Generalized anxiety disorder

Generalized anxiety disorder (GAD) is an anxiety disorder characterized by excessive, uncontrollable and often irrational worry about events or activities.<ref name="DSM-5">Template:Cite book</ref> Worry often interferes with daily functioning. Individuals with GAD are often overly concerned about everyday matters such as health, finances, death, family, relationship concerns, or work difficulties.<ref name="nimh">"What Is Generalized Anxiety Disorder?", National Institute of Mental Health. Accessed 28 May 2008.</ref><ref>Template:Cite journal</ref> Symptoms may include excessive worry, restlessness, trouble sleeping, exhaustion, irritability, sweating, and trembling.<ref name=NIH2019>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref>

Symptoms must be consistent and ongoing, persisting at least six months for a formal diagnosis.<ref name="DSM-5" /><ref name="nimh" /> Individuals with GAD often have other disorders including other psychiatric disorders, substance use disorder, or obesity, and may have a history of trauma or family with GAD.<ref name=":3">Template:Cite book</ref> Clinicians use screening tools such as the GAD-7 and GAD-2 questionnaires to determine if individuals may have GAD and warrant formal evaluation for the disorder. In addition, screening tools may enable clinicians to evaluate the severity of GAD symptoms.<ref>Template:Cite journal</ref><ref>Template:Cite journal</ref>

Treatment includes types of psychotherapy and pharmacological intervention.<ref name=":2">Template:Cite journal</ref><ref name=":3" /> CBT and selective serotonin reuptake inhibitors (SSRIs) are first-line psychological and pharmacological treatments; other options include serotonin–norepinephrine reuptake inhibitors (SNRIs). In more severe, last resort cases, benzodiazepines, though not as first-line drugs as benzodiazepines are frequently abused and habit forming. In Europe, pregabalin is also used.<ref>European Medicines Agency. EPAR summary for the public (Lyrica/pregabalin) EMA/229012/2010.</ref> The potential effects of complementary and alternative medications (CAMs), exercise, therapeutic massage and other interventions have been studied.<ref>Template:Cite journal</ref><ref name=":9" /> Brain stimulation, exercise, LSD, and other novel therapeutic interventions also under study.

Genetic and environmental factors both contribute to GAD. A hereditary component influenced by brain structure and neurotransmitter function interacts with life stressors such as parenting style and abusive relationships. Emerging evidence also links problematic digital media use to increased anxiety. GAD involves heightened amygdala and prefrontal cortex activity, reflecting an overactive threat-response system. It affects about 2–6% of adults worldwide, usually begins in adolescence or early adulthood, is more common in women, and often recurs throughout life. GAD was defined as a separate diagnosis in 1980, with changing criteria over time that have complicated research and treatment development.Template:TOC limit

Causes

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Genetics, family and environment

The relationship between genetics and anxiety disorders is an ongoing area of research.<ref name=":6">Template:Cite journal</ref> It is broadly understood that there exists a hereditary basis for GAD, but the exact nature of this hereditary basis is not fully understood.<ref name=":3" />  While investigators have identified several genetic loci that are regions of interest for further study, there is no singular gene or set of genes that have been identified as causing GAD.<ref name=":6" />  Nevertheless, genetic factors may play a role in determining whether an individual is at greater risk for developing GAD,<ref name=":7">Template:Cite book</ref> structural changes in the brain related to GAD,<ref name=":02" /> or whether an individual is more or less likely to respond to a particular treatment modality.<ref name=":7" />  Genetic factors that may play a role in development of GAD are usually discussed in view of environmental factors (e.g., life experience or ongoing stress) that might also play a role in development of GAD.<ref name=":8">Template:Cite journal</ref> The traditional methods of investigating the possible hereditary basis of GAD include using family studies and twin studies (there are no known adoption studies of individuals who have anxiety disorders, including GAD).<ref name=":3" /><ref name=":8" /> Meta-analysis of family and twin studies suggests that there is strong evidence of a hereditary basis for GAD in that GAD is more likely to occur in first-degree relatives of individuals who have GAD than in non-related individuals in the same population.<ref name=":8" /> Twin studies also suggest that there may be a genetic linkage between GAD and major depressive disorder (MDD), which may explain the common occurrence of MDD in individuals who have GAD (e.g., comorbidity of MDD in individuals with GAD has been estimated at 60%<ref>Template:Cite journal</ref>).<ref name=":3" /><ref>Template:Cite journal</ref> When GAD is considered among all anxiety disorders (e.g., panic disorder, social anxiety disorder), genetic studies suggest that hereditary contribution to the development of anxiety disorders amounts to only approximately 30–40%, which suggests that environmental factors are likely more important to determining whether an individual may develop GAD.<ref name=":3" /><ref name=":8" /> In regard to environmental influences in the development of GAD, it has been suggested that parenting behaviour may be an important influence since parents potentially model anxiety-related behaviours.<ref name=":3" /> It has also been suggested that individuals with GAD have experienced a greater number of minor stress-related events in life and that the number of stress-related events may be important in development of GAD (irrespective of other individual characteristics).<ref name=":3" /> Further research on the life context and social factors of individuals with GAD has provided greater insight into the influence of interpersonal relationships, with one study noting strong associations between partner abuse in women with the anxiety apparent in GAD.<ref>Template:Cite journal</ref> Thus, strained or stressful social relationships, as evidenced by abusive partners, display some association with the emergence of anxiety as a symptom of GAD.

Studies of possible genetic contributions to the development of GAD have examined relationships between genes implicated in brain structures involved in identifying potential threats (e.g., in the amygdala) and also implicated in neurotransmitters and neurotransmitter receptors known to be involved in anxiety disorders.<ref name=":02">Template:Cite journal</ref> More specifically, genes studied for their relationship to development of GAD or demonstrated to have had a relationship to treatment response include:

• PACAP (A54G polymorphism): remission after 6-month treatment with Venlafaxine suggested to have a significant relationship with the A54G polymorphism (Cooper et al. (2013))<ref name=":02" />
• HTR2A gene (rs7997012 SNP G allele): HTR2A allele suggested to be implicated in a significant decrease in anxiety symptoms associated with response to six months of Venlafaxine treatment (Lohoff et al. (2013))<ref name=":02" />
• SLC6A4 promoter region (5-HTTLPR): Serotonin transporter gene suggested to be implicated in significant reduction in anxiety symptoms in response to six months of Venlafaxine treatment (Lohoff et al. (2013))<ref name=":02" />

Pathophysiology

File:Amygdala small.gif

Amygdala (in red) brain structures linked to anxiety disorders

The pathophysiology of GAD is an active and ongoing area of research often involving the intersection of genetics and neurological structures.<ref name=":3" /> GAD has been linked to changes in functional connectivity of the amygdala and its processing of fear and anxiety.<ref name="Etkin">Template:Cite journal</ref> Sensory information enters the amygdala through the nuclei of the basolateral complex (consisting of lateral, basal and accessory basal nuclei).<ref name="Etkin" /> The basolateral complex processes the sensory-related fear memories and communicates information regarding threat importance to memory and sensory processing elsewhere in the brain, such as the medial prefrontal cortex and sensory cortices.<ref name="Etkin" /> Neurological structures traditionally appreciated for their roles in anxiety include the amygdala, insula and orbitofrontal cortex (OFC).<ref name=":3" /> It is broadly postulated that changes in one or more of these neurological structures are believed to allow greater amygdala response to emotional stimuli in individuals who have GAD as compared to individuals who do not have GAD.<ref name=":3" />

Individuals with GAD have been suggested to have greater amygdala and medial prefrontal cortex (mPFC) activation in response to stimuli than individuals who do not have GAD.<ref name=":3" /> However, the exact relationship between the amygdala and the frontal cortex (e.g., prefrontal cortex or the orbitofrontal cortex [OFC]) is not fully understood because there are studies that suggest increased or decreased activity in the frontal cortex in individuals who have GAD.<ref name=":3" /> Consequently, because of the tenuous understanding of the frontal cortex as it relates to the amygdala in individuals who have GAD, it's an open question as to whether individuals who have GAD bear an amygdala that is more sensitive than an amygdala in an individual without GAD or whether frontal cortex hyperactivity is responsible for changes in amygdala responsiveness to various stimuli.<ref name=":3" /> Recent studies have attempted to identify specific regions of the frontal cortex (e.g., dorsomedial prefrontal cortex [dmPFC]) that may be more or less reactive in individuals who have GAD<ref name=":3" /> or specific networks that may be differentially implicated in individuals who have GAD.<ref name="Etkin" /> Other lines of study investigate whether activation patterns vary in individuals who have GAD at different ages with respect to individuals who do not have GAD at the same age (e.g., amygdala activation in adolescents with GAD).<ref name=":3" />

Evolutionary Explanations

From an evolutionary perspective, generalized anxiety can be viewed as an overextension of the protective mechanisms that help organisms avoid danger. Cost–benefit analyses, sometimes referred to as the “smoke detector principle,”<ref>Template:Cite journal</ref> propose that false alarms (unnecessary worry) are less costly than failing to detect real threats. As a result, having a relatively low threshold for perceiving danger may have historically conferred survival benefits. In individuals with GAD, however, this adaptive threshold appears to be set too low or activated too often, generating pervasive worry about routine events and relatively minor stressors.<ref>Template:Cite book</ref>

Empirical work supports the idea that GAD involves heightened reactivity in brain regions associated with threat detection, including the amygdala. Researchers have also found links between GAD and elevated inflammation markers, suggesting a possible physiological correlate for the chronic anxiety seen in the disorder. Although anxiety's defensive functions may have been advantageous in unpredictable environments, modern contexts can render this vigilance maladaptive when it persists as near-constant worry and avoidance. This view places GAD at the extreme end of a continuum, where otherwise beneficial anxiety responses overshoot, leading to significant distress and functional impairment.<ref>Template:Cite book</ref>

Diagnosis

DSM-5 criteria

The diagnostic criteria for GAD as defined by the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5),<ref name="DSM-5" /> published by the American Psychiatric Association, are paraphrased as follows:<ref name="DSM-5" />Template:Ordered listNo major changes to GAD have occurred since publication of the Diagnostic and Statistical Manual of Mental Disorders (2004); minor changes include wording of diagnostic criteria.<ref>Template:Cite journal</ref>

ICD-10 criteria

The 10th revision of the International Statistical Classification of Disease (ICD-10) provides a different set of diagnostic criteria for GAD than the DSM-5 criteria described above. In particular, ICD-10 allows diagnosis of GAD as follows:

Template:Ordered listSee ICD-10 F41.1<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> Note: For children different ICD-10 criteria may be applied for diagnosing GAD (see F93.80).

Treatment

Traditional treatment modalities broadly fall into two categories, i.e., psychotherapeutic and pharmacological intervention.<ref name=":2"/> In addition to these two conventional therapeutic approaches, areas of active investigation include complementary and alternative medications (CAMs), brain stimulation, exercise, therapeutic massage, balneotherapy and other interventions that have been proposed for further study.<ref name=":12">Template:Cite journal</ref> MindMed’s MM120 (a form of lysergic acid diethylamide; LSD) is also being investigated in clinical settings after it showed strong, lasting anxiety relief after one dose in a Phase 2b trial, earning FDA breakthrough status and advancing to Phase 3 in 2024.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> Treatment modalities can, and often are, utilized concurrently so that an individual may pursue psychological therapy (i.e., psychotherapy) and pharmacological therapy.<ref name=":53">Template:Cite journal</ref> Both cognitive behavioral therapy (CBT) and medications (such as SSRIs) have been shown to be effective in reducing anxiety.<ref name=":10">Template:Cite journal</ref> A combination of both CBT and medication is generally seen as the most desirable approach to treatment.<ref name="Bandelow">Template:Cite journal</ref> Use of medication to lower extreme anxiety levels can be important in enabling patients to engage effectively in CBT.Template:Cn

Psychotherapy

Psychotherapeutic interventions<ref name="Strawn 1057–1070">Template:Cite journal</ref> include a plurality of therapy types that vary based upon their specific methodologies for enabling individuals to gain insight into the working of the conscious and subconscious mind and which sometimes focus on the relationship between cognition and behavior.<ref name=":32">Template:Cite book</ref><ref name=":53"/> Cognitive behavioral therapy (CBT) is widely regarded as the first-line psychological therapy for treating GAD.<ref name=":53" /> Additionally, many of these psychological interventions may be delivered in an individual or group therapy setting.<ref name=":53" /> While individual and group settings are broadly both considered effective for treating GAD, individual therapy tends to promote longer-lasting engagement in therapy (i.e., lower attrition over time).<ref name=":53" />

For children, the role of the parent is important. They serve as co-therapists who make sure the tasks set by the therapists are implemented and for giving children positive reinforcement throughout the tasks. The "transfer of control" model highlights the growing responsibility of the parents as the role of the therapist fades away. <ref>Template:Cite journal</ref>

Psychodynamic therapy

Psychodynamic therapy is a type of therapy premised upon Freudian psychology in which a psychologist enables an individual explore various elements in their subconscious mind to resolve conflicts that may exist between the conscious and subconscious elements of the mind.<ref>Template:Cite journal</ref><ref name=":53" /> In the context of GAD, the psychodynamic theory of anxiety suggests that the unconscious mind engages in worry as a defense mechanism to avoid feelings of anger or hostility because such feelings might cause social isolation or other negative attribution toward oneself.<ref name=":32" /> Accordingly, the various psychodynamic therapies attempt to explore the nature of worry as it functions in GAD in order to enable individuals to alter the subconscious practice of using worry as a defense mechanism<ref name=":32" /> and to thereby diminish GAD symptoms.<ref name=":53" /> Variations of psychotherapy include a near-term version of therapy, "short-term anxiety-provoking psychotherapy (STAPP).<ref name=":53" />

Behavioral therapy

Behavioral therapy is therapeutic intervention premised upon the concept that anxiety is learned through classical conditioning (e.g., in view of one or more negative experiences) and maintained through operant conditioning (e.g., one finds that by avoiding a feared experience that one avoids anxiety). Thus, behavioral therapy enables an individual to re-learn conditioned responses (behaviors) and to thereby challenge behaviors that have become conditioned responses to fear and anxiety, and which have previously given rise to further maladaptive behaviors.<ref name=":32" />

Cognitive therapy

Cognitive therapy (CT) is premised upon the idea that anxiety is the result of maladaptive beliefs and methods of thinking.<ref name=":32" /> Thus, CT involves assisting individuals to identify more rational ways of thinking and to replace maladaptive thinking patterns (i.e., cognitive distortions) with healthier thinking patterns (e.g., replacing the cognitive distortion of catastrophizing with a more productive pattern of thinking).<ref name=":32" /> Individuals in CT learn how to identify objective evidence, test hypotheses, and ultimately identify maladaptive thinking patterns so that these patterns can be challenged and replaced.<ref name=":32" />

Acceptance and commitment therapy

Acceptance and commitment therapy (ACT) is a behavioral treatment based on acceptance-based models. ACT is designed with the purpose to target three therapeutic goals: (1) reduce the use of avoiding strategies intended to avoid feelings, thoughts, memories, and sensations; (2) decreasing a person's literal response to their thoughts (e.g., understanding that thinking "I'm hopeless" does not mean that the person's life is truly hopeless), and (3) increasing the person's ability to keep commitments to changing their behaviors. These goals are attained by switching the person's attempt to control events to working towards changing their behavior and focusing on valued directions and goals in their lives as well as committing to behaviors that help the individual accomplish those personal goals.<ref>Template:Cite journal</ref> This psychological therapy teaches mindfulness (paying attention on purpose, in the present, and in a nonjudgmental manner) and acceptance (openness and willingness to sustain contact) skills for responding to uncontrollable events and therefore manifesting behaviors that enact personal values.<ref>Template:Cite journal</ref>

Intolerance of uncertainty therapy

Intolerance of uncertainty (IU) refers to a consistent negative reaction to uncertain and ambiguous events regardless of their likelihood of occurrence. Intolerance of uncertainty therapy (IUT) is used as a stand-alone treatment for GAD patients. Thus, IUT focuses on helping patients in developing the ability to tolerate, cope with and accept uncertainty in their life in order to reduce anxiety. IUT is based on the psychological components of psychoeducation, awareness of worry, problem-solving training, re-evaluation of the usefulness of worry, imagining virtual exposure, recognition of uncertainty, and behavioral exposure. Studies have shown support for the efficacy of this therapy with GAD patients with continued improvements in follow-up periods.<ref name="Hoyer, J. 2011">Template:Cite journal</ref>

Motivational interviewing

A promising innovative approach to improving recovery rates for the treatment of GAD is to combine CBT with motivational interviewing (MI). Motivational interviewing is a strategy centered on the patient that aims to increase intrinsic motivation and decrease ambivalence about change due to the treatment. MI contains four key elements: (1) express empathy, (2) heighten dissonance between behaviors that are not desired and values that are not consistent with those behaviors, (3) move with resistance rather than direct confrontation, and (4) encourage self-efficacy. It is based on asking open-ended questions and listening carefully and reflectively to patients' answers, eliciting "change talk", and talking with patients about the pros and cons of change. Some studies have shown the combination of CBT with MI to be more effective than CBT alone.<ref name="Hoyer, J. 2011" />

Cognitive behavioral therapy

Cognitive behavioral therapy (CBT) is an evidence-based type of psychotherapy that demonstrates efficacy in treating GAD and which integrates the cognitive and behavioral therapeutic approaches.<ref name=":53" /> The objective of CBT is to enable individuals to identify irrational thoughts that cause anxiety and to challenge dysfunctional thinking patterns by engaging in awareness techniques such as hypothesis testing and journaling.<ref name=":53" /> Because CBT involves the practice of worry and anxiety management, CBT includes a plurality of intervention techniques that enable individuals to explore worry, anxiety and automatic negative thinking patterns.<ref name=":53" /> These interventions include anxiety management training, cognitive restructuring,<ref name=":62">Template:Cite journal</ref> progressive relaxation,<ref name=":62" /> situational exposure and self-controlled desensitization.<ref name=":53" /> Several modes of delivery are effective in treating GAD, including internet-delivered CBT, or iCBT.<ref>Template:Cite journal</ref>

Emotion-focused therapy

Emotion-focused therapy (EFT) is a short-term psychotherapy that is focused on humanistic needs of emotions when treating individuals with GAD. EFT can incorporate numerous practices such as experimental therapy, systemic therapy, and elements of CBT to allow individuals to work through difficult emotional states.<ref>Template:Cite journal</ref> The primary goal of EFT is assisting individuals in living with their vulnerable emotions and overcoming avoidance so that adaptive experiences such as compassion and protective anger can be generated in response to the emotional needs that are embedded in core emotional vulnerability.

Sandplay therapy

Sandplay therapy (SPT) is an intervention based on nonverbal therapeutic practices. The main objective of SPT is to allow the individual the ability to work through their emotional problems from childhood traumas (CT) through play using sand and toy figures.<ref>Template:Cite journal</ref> Although the therapy is mainly focused on nonverbal cues, verbal cues are also observed and documented during the rehabilitation process of the individual.<ref>Template:Cite journal</ref> SPT allows a multi-sensory experience through a safe and protected space allowing the individual the opportunity to regulate their mind and emotions. This therapeutic practice is offered in both adults and children.

Exposure therapy

There is empirical evidence that exposure therapy can be an effective treatment for people with GAD, citing specifically in vivo exposure therapy (exposure through a real-life situation),<ref name="Kaplan_2021">Template:Cite journal</ref> which has greater effectiveness than imaginal exposure in regards to generalized anxiety disorder. The aim of in vivo exposure treatment is to promote emotional regulation using systematic and controlled therapeutic exposure to traumatic stimuli.<ref>Template:Cite journal</ref> Exposure is used to promote fear tolerance.<ref>"Instead of teaching patients to resist, control or "fix" their fear or anxiety, exposure is used to promote 'fear tolerance' given that fear and anxiety are universal, inevitable and safe." Exposure Therapy for Anxiety, Second Edition (2019), p18, Abramowitz, Deacon and Whiteside</ref>

Exposure therapy is also a preferred method for children who struggle with anxiety.<ref>Template:Cite journal</ref> Children also typically prefer using a group format for exposure therapy treatment. This allows for peer learning and the opportunity to develop social skills. <ref>Template:Cite journal</ref>

Other forms of psychological therapy

• Relaxation techniques (e.g., relaxing imagery, meditational relaxation)<ref name=":53" />
• Metacognitive therapy (MCT): The objective of MCT is to alter thinking patterns regarding worry so that worry is no longer used as a coping strategy. It has promising results in treatment of GAD as well as other mental issues.<ref>Template:Cite journal</ref>
• Mindfulness based stress reduction (MBSR)<ref name=":32" />
• Mindfulness based cognitive therapy (MBCT):<ref name=":32" /> The goal of MBCT is to be used as an alternative or adjunctive to Cognitive Behavior Therapy (CBT).<ref>Template:Cite book</ref>
• Supportive therapy: This is a Rogerian method of therapy in which subjects experience empathy and acceptance from their therapist to facilitate increasing awareness.<ref name=":53" /> Variations of active supportive therapy include Gestalt therapy, Transactional analysis and Counseling.<ref name=":53" />
• Internet-delivered interpretation training: The focus of this training is to reduce worry and anxiety while promoting positive outcomes and positive interpretations.<ref>Template:Cite journal</ref>

Pharmacotherapy

Medications that have been studied were reviewed in a recent network meta-analysis that compared all studied medications with placebo and also with each other <ref name="pmid30712879">Template:Cite journal</ref> and another compared the rates of remission between different medications.<ref name="pmid33343351">Template:Cite journal</ref> Benzodiazepines (BZs) have been used to treat anxiety starting in the 1960s.<ref>Template:Cite news</ref> There is a risk of dependence and tolerance to benzodiazepines.<ref name=":53" /><ref name=":72">Template:Cite journal</ref> BZs have a number of effects that make them a good option for treating anxiety including anxiolytic, hypnotic (induce sleep), myorelaxant (relax muscles), anticonvulsant, and amnestic (impair short-term memory) properties.<ref name=":72" /> While BZs work well to alleviate anxiety shortly after administration, they are also known for their ability to promote dependence and are frequently used recreationally or non-medically.<ref name="Strawn 1057–1070"/><ref name=":72" /> Antidepressants (e.g., SSRIs / SNRIs) have become a mainstay in treating GAD in adults.<ref name=":53" /><ref name=":10" /> First-line medications from any drug category often include those that have been approved by the Food and Drug Administration (FDA) or other similar regulatory body such as the EMA or TGA for treating GAD because these drugs have been shown to be safe and effective.<ref name="Strawn 1057–1070"/>

FDA-approved medications for treating GAD

FDA-approved medications for treating GAD include:<ref name="Strawn 1057–1070"/><ref name=":53" /><ref name=":02"/><ref>Escitalopram Oxalate: Mechanism of Action. (2020). In Micromedex for iOS (Version No. 1.81.0b3005) [electronic version]. Retrieved 8 November 2020.</ref><ref>Venlafaxine Hydrochloride: Mechanism of Action. (2020). In Micromedex for iOS (Version No. 1.81.0b3005) [electronic version]. Retrieved 8 November 2020.</ref><ref name=":43">Template:Cite journal</ref>Template:Excessive citations inline Template:Ordered list

Non-FDA approved medications

While certain medications are not specifically FDA approved for treatment of GAD, there are a number of medications that historically have been used or studied for treating GAD.<ref name=":43"/> Other medications that have been used or evaluated for treating GAD include:

• SSRIs
  • Citalopram<ref name="Strawn 1057–1070"/>
  • Fluoxetine<ref name="Strawn 1057–1070"/>
  • Sertraline<ref name="Strawn 1057–1070"/><ref name=":43"/>
  • Fluvoxamine<ref name=":43"/>
• Benzodiazepines
  • Clonazepam<ref name="Strawn 1057–1070"/>
  • Lorazepam<ref name="Strawn 1057–1070"/>
  • Diazepam<ref name="Strawn 1057–1070"/>
• GABA analogs
  • Pregabalin<ref name="Strawn 1057–1070"/><ref name=":02" /><ref name=":43"/><ref name=":1">Template:Cite journal</ref><ref>Template:Cite journal</ref>Template:Excessive citations inline
  • Tiagabine<ref name="Strawn 1057–1070"/>
• Second-generation antipsychotics
  • Olanzapine (evidence of effectiveness is merely a trend)<ref name="Strawn 1057–1070"/>
  • Ziprasidone<ref name="Strawn 1057–1070"/>
  • Risperidone<ref name="Strawn 1057–1070"/>
  • Aripiprazole (studied as an adjunctive measure in concert with other treatment)<ref name="Strawn 1057–1070"/>
  • Quetiapine (atypical antipsychotic studied as an adjunctive measure in adults and geriatric patients)<ref name="Strawn 1057–1070"/><ref name=":02" />
• Antihistamines
  • Hydroxyzine (H₁ receptor antagonist)<ref name="Strawn 1057–1070"/><ref name=":43" />
  • Mirtazapine (atypical antidepressant having 5-HT_2A and 5-HT_2C receptor affinity)<ref name="Strawn 1057–1070" />
• Tricyclic antidepressants
  • Amitriptyline<ref name="Strawn 1057–1070"/>
  • Clomipramine<ref name="Strawn 1057–1070"/>
  • Doxepin<ref name="Strawn 1057–1070"/>
  • Imipramine<ref name="Strawn 1057–1070"/>
  • Trimipramine<ref name="Strawn 1057–1070"/>
  • Desipramine<ref name="Strawn 1057–1070"/>
  • Nortriptyline<ref name="Strawn 1057–1070"/>
  • Protriptyline<ref name="Strawn 1057–1070"/>
  • Opipramol (atypical TCA)<ref name=":43"/>
  • Trazodone<ref name="Strawn 1057–1070"/>
• Monoamine oxidase inhibitors (MAOIs)
  • Tranylcypromine<ref name="Strawn 1057–1070"/>
  • Phenelzine<ref name="Strawn 1057–1070"/>

Selective serotonin reuptake inhibitors

Pharmaceutical treatments for GAD include selective serotonin reuptake inhibitors (SSRIs).<ref name="mayo">"Generalized anxiety disorder", Mayo Clinic. Accessed 29 May 2007.</ref> SSRIs increase serotonin levels through inhibition of serotonin reuptake receptors.<ref>Template:Cite journal</ref>

FDA approved SSRIs used for this purpose include escitalopram<ref name="pmid19961809">Template:Cite journal</ref> and paroxetine.<ref>Template:Cite journal</ref> However, guidelines suggest using sertraline first due to its cost-effectiveness compared to other SSRIs used for generalized anxiety disorder and a lower risk of withdrawal compared to SNRIs. If sertraline is found to be ineffective, then it is recommended to try another SSRI or SNRI.<ref name=":0">{{#invoke:citation/CS1|citation |CitationClass=web }}</ref>

Common side effects include nausea, sexual dysfunction, headache, diarrhea, constipation, restlessness, increased risk of suicide in young adults and adolescents,<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> among others. Sexual side effects, weight gain, and higher risk of withdrawal are more common in paroxetine than escitalopram and sertraline.<ref>Template:Cite journal</ref> In older populations or those taking concomitant medications that increase risk of bleeding, SSRIs may further increase the risk of bleeding.<ref name=":0" /> Overdose of an SSRI or concomitant use with another agent that causes increased levels of serotonin can result in serotonin syndrome, which can be life-threatening.

Serotonin norepinephrine reuptake inhibitors

First line pharmaceutical treatments for GAD also include serotonin-norepinephrine reuptake inhibitors (SNRIs).<ref>Template:Cite journal</ref> These inhibit the reuptake of serotonin and noradrenaline to increase their levels in the CNS.<ref>Template:Cite journal</ref>

FDA approved SNRIs used for this purpose include duloxetine (Cymbalta) and venlafaxine (Effexor).<ref name="Strawn 1057–1070"/><ref>Template:Cite journal</ref> While SNRIs have similar efficacy as SSRIs,<ref>Template:Cite journal</ref> many psychiatrists prefer to use SSRIs first in the treatment of Generalized Anxiety Disorder.<ref name="Strawn 1057–1070" /><ref>Template:Cite journal</ref><ref>Template:Cite journal</ref><ref name="Katzman 2014 S1">Template:Cite journal</ref> The slightly higher preference for SSRIs over SNRIs as a first choice for treatment of anxiety disorders may have been influenced by the observation of poorer tolerability of the SNRIs in comparison to SSRIs in systematic reviews of studies of depressed patients.<ref name=":10" /><ref>Template:Cite journal</ref><ref>Template:Cite journal</ref><ref>Template:Cite journal</ref>

Side effects common to both SNRIs include anxiety, restlessness, nausea, weight loss, insomnia, dizziness, drowsiness, sweating, dry mouth, sexual dysfunction and weakness.<ref name="Santarsieri 2015 212290">Template:Cite journal</ref> In comparison to SSRIs, the SNRIs have a higher prevalence of the side effects of insomnia, dry mouth, nausea and high blood pressure.<ref name="Santarsieri 2015 212290" /><ref>Template:Cite journal</ref> Both SNRIs have the potential for discontinuation syndrome after abrupt cessation, which can precipitate symptoms including motor disturbances and anxiety and may require tapering.<ref name="Chow 2017 169–170">Template:Citation</ref><ref>Template:Cite journal</ref> Like other serotonergic agents, SNRIs have the potential to cause serotonin syndrome, a potentially fatal systemic response to serotonergic excess that causes symptoms including agitation, restlessness, confusion, tachycardia, hypertension, mydriasis, ataxia, myoclonus, muscle rigidity, diaphoresis, diarrhea, headache, shivering, goose bumps, high fever, seizures, arrhythmia and unconsciousness.<ref>Template:Cite journal</ref> SNRIs like SSRIs carry a black box warning for suicidal ideation, but it is generally considered that the risk of suicide in untreated depression is far higher than the risk of suicide when depression is properly treated.<ref>Template:Cite journal</ref>

Pregabalin and gabapentin

Pregabalin (Lyrica) is effective for treating GAD.<ref>Template:Cite journal</ref><ref name=":13">Template:Cite journal</ref> It acts on the voltage-dependent calcium channel to decrease the release of neurotransmitters such as glutamate, norepinephrine and substance P. Its therapeutic effect appears after one week of use and is similar in effectiveness to lorazepam, alprazolam and venlafaxine but pregabalin has demonstrated superiority by producing more consistent therapeutic effects for psychic and somatic anxiety symptoms. Long-term trials have shown continued effectiveness without the development of tolerance and additionally, unlike benzodiazepines, it does not disrupt sleep architecture and produces less severe cognitive and psychomotor impairment. It also has a low potential for misuse and dependency and may be preferred over the benzodiazepines for these reasons.<ref>Template:Cite journal</ref><ref>Template:Cite journal</ref> The anxiolytic effects of pregabalin appear to persist for at least six months continuous use, suggesting tolerance is less of a concern; this gives pregabalin an advantage over certain anxiolytic medications such as benzodiazepines.<ref name="pmid22395254">Template:Cite journal</ref>

Gabapentin (Neurontin), a closely related medication to pregabalin with the same mechanism of action, has also demonstrated effectiveness in the treatment of GAD,<ref name="El-MallakhGhaemi2007">Template:Cite book</ref> though unlike pregabalin, it has not been approved specifically for this indication. Nonetheless, it is likely to be of similar usefulness in the management of this condition, and by virtue of being off-patent, it has the advantage of being significantly less expensive in comparison.<ref name="StahlMoore2013">Template:Cite book</ref> In accordance, gabapentin is frequently prescribed off-label to treat GAD.<ref name="ReynoldsColeman2011">Template:Cite book</ref>

Complementary and alternative medicines studied for potential in treating GAD

Complementary and alternative medicines (CAMs) are widely used by individuals with GAD despite having no evidence or varied evidence regarding efficacy.<ref name=":12"/> Efficacy trials for CAM medications often have various types of bias and low quality reporting in regard to safety.<ref name=":12"/> In regard to efficacy, critics point out that CAM trials sometimes predicate claims of efficacy based on a comparison of a CAM against a known drug after which no difference in subjects is found by investigators and which is used to suggest an equivalence between a CAM and a drug. Because this equates a lack of evidence with the positive assertion of efficacy, a "lack of difference" assertion is not a proper claim for efficacy.<ref name=":12"/> Moreover, an absence of strict definitions and standards for CAM compounds further burdens the literature regarding CAM efficacy in treating GAD.<ref name=":12"/> CAMs academically studied for their potential in treating GAD or GAD symptoms along with a summary of academic findings are given below. What follows is a summary of academic findings. Accordingly, none of the following should be taken as offering medical guidance or an opinion as to the safety or efficacy of any of the following CAMs.

1. Kava (Piper methysticum) extracts: Meta-analysis does not suggest efficacy of kava extracts due to few data available yielding inconclusive results or non-statistically significant results.<ref name=":12"/> Nearly a quarter (25.8%) of subjects experienced adverse effects (AEs) from Kava Kava extracts during six trials.<ref name=":12"/> Traditional kava is low-risk; solvent-based extracts or poor-quality forms may harm the liver.<ref>Template:Cite report</ref>
2. Lavender (Lavandula angustifolia) extracts: Small and varied studies may suggest some level of efficacy as compared to placebo or other medication; claims of efficacy are regarded as needing further evaluation.<ref name=":12"/><ref name="Strawn 1057–1070"/> Silexan is an oil derivative of Lavender studied in pediatric patients with GAD.<ref name="Strawn 1057–1070"/> Concern exists regarding the question as to whether Silexan may cause unopposed estrogen exposure in boys due to disruption of steroid signaling.<ref name="Strawn 1057–1070"/>
3. Galphimia glauca extracts: While Galphima glauca extracts have been the subject of two randomised controlled trials (RCTs) comparing Galphima glauca extracts to lorazepam, efficacy claims are regarded as "highly uncertain."<ref name=":12"/>
4. Chamomile (Matricaria chamomilla) extracts: Poor quality trials have trends that may suggest efficacy but further study is needed to establish any claim of efficacy.<ref name=":12"/>
5. Crataegus oxycantha and Eschscholtzia californica extracts combined with magnesium: A single 12-week trial of Crataegus oxycantha and Eschscholtzia californica compared to placebo has been used to suggest efficacy. However, efficacy claims require confirmation studies.<ref name=":12"/> For the minority of subjects who experienced AEs from extracts, most AEs implicated gastrointestinal tract (GIT) intolerance.<ref name=":12"/>
6. Echium amoneum extract: A single, small trial used this extract as a supplement to fluoxetine (vs using a placebo to supplement fluoxetine); larger studies are needed to substantiate efficacy claims.<ref name=":12"/>
7. Gamisoyo-San: Small trials of this herbal mixture compared to placebo have suggested no efficacy of the herbal mixture over placebo but further study is necessary to allow definitive conclusion of a lack of efficacy.<ref name=":12"/>
8. Passiflora incarnata extract: Claims of efficacy or benzodiazepine equivalence are regarded as "highly uncertain."<ref name=":12"/>
9. Valeriana extract: A single 4-week trial suggests no effect of Valeriana extract on GAD but is regarded as "uninformative" on the topic of efficacy in view of its finding that the benzodiazepine diazepam also had no effect.<ref name=":12"/> Further study may be warranted.<ref name=":12"/>

A 2022 meta-analysis found that some herbs—particularly lavender (Silexan), kava, Ginkgo biloba, and Withania somnifera—show promise for treating anxiety, though overall evidence remains preliminary due to small sample sizes and possible placebo effects.<ref name=":9">Template:Cite journal</ref>

Lifestyle

Lifestyle factors including: stress management, stress reduction, relaxation, sleep hygiene, and caffeine and alcohol reduction can influence anxiety levels. Physical activity has shown to have a positive impact whereas low physical activity may be a risk factor for anxiety disorders.<ref>Template:Cite journal</ref>

Engaging in physical activity appears to significantly reduce the risk of developing anxiety symptoms and disorders, though limitations in study quality and consistency highlight the need for further research.<ref>Template:Cite journal</ref>

Substances and GAD

Certain substances or the withdrawal from certain substances have been implicated in promoting the experience of anxiety.<ref name="Strawn 1057–1070"/> For example, even while benzodiazepines may afford individuals with GAD relief from anxiety, withdrawal from benzodiazepines is associated with the experience of anxiety among other adverse events like sweating and tremor.<ref name="Strawn 1057–1070"/>

Nicotine withdrawal symptoms may provoke anxiety in tobacco smokers<ref>Template:Cite journal</ref> and excessive caffeine use has been linked to aggravating and maintaining anxiety.<ref>Template:Cite journal</ref>

Comorbidity

Depression

A longitudinal cohort study found 12% of 972 participants had GAD comorbid with major depressive disorder.<ref name="MDDandGAD">Template:Cite journal</ref> Accumulating evidence indicates that patients with comorbid depression and anxiety tend to have greater illness severity and a lower treatment response than those with either disorder alone.<ref name="Wolitzky-Taylor et al-2010">Template:Cite journal</ref> In addition, social function and quality of life are more greatly impaired.

For many, the symptoms of both depression and anxiety are not severe enough (i.e., are subsyndromal) to justify a primary diagnosis of either major depressive disorder (MDD) or an anxiety disorder. However, dysthymia is the most prevalent comorbid diagnosis of GAD clients. Patients can also be categorized as having mixed anxiety-depressive disorder, though this is an unstable diagnosis that typically either goes away or shifts to a different diagnosis later on.<ref>Template:Cite journal</ref>

Various explanations for the high comorbidity between GAD and depressive disorders have been suggested, ranging from genetic pleiotropy (i.e., GAD and nonbipolar depression might represent different phenotypic expressions of a common etiology <ref name="Crocq2017">Template:Cite journal</ref>) to impaired executive control <ref name="Coussement, De Longueville, & Heeren-2022">Template:Cite journal</ref> or sleep problems and fatigue as potential bridging mechanisms between the two disorders.<ref name="Coussement & Heeren-2022">Template:Cite journal</ref>

Both disorders are found to be precede each other, or help the other develop. In 32% of anxiety cases, depression was seen to begin before or concurrently, while in 37% of depression cases, anxiety was seen to begin before or concurrently. Within 72% of anxiety cases, a history of depression was found. <ref name="MDDandGAD" />

Comorbidity and treatment

Therapy has been shown to have equal efficacy in patients with GAD and patients with GAD and comorbid disorders. Patients with comorbid disorders have more severe symptoms when starting therapy, but demonstrated a greater improvement than patients with GAD alone.Template:Citation needed

Pharmacological approaches (i.e., the use of antidepressants) must be adapted for different comorbidities. For example, selective serotonin reuptake inhibitors (SSRIs) and benzodiazepines are used for depression and anxiety. However, for patients with anxiety and a substance use disorder, benzodiazepines should be avoided due to their addictive properties.<ref>Template:Cite journal</ref> CBT has been found an effective treatment since it improves symptoms of GAD and substance use.

Compared to the general population, patients with internalizing disorders such as depression, generalized anxiety disorder, and post-traumatic stress disorder (PTSD) have higher mortality rates, but die of the same age-related diseases as the population, such as heart disease, cerebrovascular disease and cancer.<ref>Template:Cite journal</ref>

Patients with GAD can sometimes present with symptoms such as insomnia or headaches.Template:Citation needed

There is also observed comorbidity between GAD and attention deficit hyperactivity disorder (ADHD). Anxiety disorders and major depressive disorder occur in a minority of individuals with ADHD, but more often than in the general population.<ref>Template:Cite book</ref> Further research suggests that about 20 to 40 percent of individuals with ADHD have comorbid anxiety disorders, with GAD being the most prevalent.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref>

Those with GAD have a lifetime comorbidity prevalence of 30% to 35% with alcohol use disorder and 25% to 30% for another substance use disorder.<ref name="Scott 2011">Scott, E. L. (2011, September 6). Anxiety Disorders With Comorbid Substance Abuse. Psychiatric Times. Retrieved July 1, 2013, from http://www.psychiatrictimes.com/anxiety/anxiety-disorders-comorbid-substance-abuse Template:Webarchive</ref> People with both GAD and a substance use disorder also have a higher lifetime prevalence for other comorbidities.<ref name="Scott 2011" /> A study found that GAD was the primary disorder in slightly more than half of the 18 participants that were comorbid with alcohol use disorder.<ref>Template:Cite journal</ref>

Epidemiology

GAD is often estimated to affect approximately 3–6% of adults and 5% of children and adolescents.<ref name="Strawn 1057–1070"/><ref name=":1" /> Although estimates have varied to suggest a GAD prevalence of 3% in children and 10.8% in adolescents.<ref>Template:Cite book</ref> When GAD manifests in children and adolescents, it typically begins around 8 to 9 years of age.<ref name="PedGAD2009">Template:Cite journal</ref>

Estimates regarding prevalence of GAD or lifetime risk (i.e., lifetime morbid risk [LMR])<ref name=":4">Template:Cite journal</ref> for GAD vary depending upon which criteria are used for diagnosing GAD (e.g., DSM-5 vs ICD-10) although estimates do not vary widely between diagnostic criteria.<ref name=":3" /> In general, ICD-10 is more inclusive than DSM-5, so estimates regarding prevalence and lifetime risk tend to be greater using ICD-10.<ref name=":3" /> In regard to prevalence, in a given year, about two (2%) percent of adults in the United States<ref name=":4" /> and Europe have been suggested to have GAD.<ref name="numbers">"The Numbers Count" Template:Webarchive, National Institute of Mental Health. Accessed 28 May 2007.</ref><ref name=":5">Template:Cite journal</ref> However, the risk of developing GAD at any point in life has been estimated at 9.0%.<ref name=":4" /> Although it is possible to experience a single episode of GAD during one's life, most people who experience GAD experience it repeatedly over the course of their lives as a chronic or ongoing condition.<ref name=":3" /> GAD is diagnosed twice as frequently in women as in men<ref name="Ged2012">Template:Cite book</ref><ref name=":3" /> and is more often diagnosed in those who are separated, divorced, unemployed, widowed or have low levels of education,<ref>Template:Cite journal</ref> and among those with low socioeconomic status.<ref name=":3" /> African Americans have higher odds of having GAD and the disorder often manifests itself in different patterns.<ref>Template:Cite journal</ref><ref>Template:Cite journal</ref> It has been suggested that greater prevalence of GAD in women may be because women are more likely than men to live in poverty, are more frequently the subject of discrimination, and be sexually and physically abused more often than men.<ref name="Schacter559">Template:Cite book</ref> In regard to the first incidence of GAD in an individual's life course, a first manifestation of GAD usually occurs between the late teenage years and the early twenties<ref name=":3" /> with the median age of onset being approximately 31<ref>Template:Cite journal</ref> and mean age of onset being 32.7.<ref name="GRANT 1747">Template:Cite journal</ref> However, GAD can begin or reoccur at any point in life.<ref name=":3" /> Indeed, GAD is common in the elderly population.<ref>Template:Cite book</ref>

United States

United States: Approximately 3.1 percent of people age 18 and over in a given year (9.5 million).<ref name="numbers" />

UK

5.9 percent of adults were affected by GAD in 2019.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref>

Other

• Australia: 3 percent of adults<ref name="WHO">"Relating the burden of anxiety and depression to effectiveness of treatment", World Health Organization.</ref>
• Canada: 2.5 percent<ref>{{#invoke:citation/CS1|citation

|CitationClass=web }}</ref>

• Italy: 2.9 percent<ref name="emed">Template:Cite journal</ref>
• Taiwan: 0.4 percent<ref name="emed" />

History

The American Psychiatric Association introduced GAD as a diagnosis in the DSM-III in 1980, when anxiety neurosis was split into GAD and panic disorder.<ref name="Crocq2017" /> The definition in the DSM-III required uncontrollable and diffuse anxiety or worry that is excessive and unrealistic and persists for one month or longer. High rates in comorbidity of GAD and major depression led many commentators to suggest that GAD would be better conceptualized as an aspect of major depression instead of an independent disorder.<ref name="Kessler 2001">Template:Cite journal</ref> Many critics stated that the diagnostic features of this disorder were not well established until the DSM-III-R.<ref name="Craighead 2013">Template:Cite book</ref> Since comorbidity of GAD and other disorders decreased with time, the DSM-III-R changed the time requirement for a GAD diagnosis to six months or longer.<ref>Template:Cite journal</ref> The DSM-IV changed the definition of excessive worry and the number of associated psychophysiological symptoms required for a diagnosis.<ref name="Kessler 2001" /> Another aspect of the diagnosis the DSM-IV clarified was what constitutes a symptom as occurring "often".<ref>Template:Cite journal</ref> The DSM-IV also required difficulty controlling the worry to be diagnosed with GAD. The DSM-5 emphasized that excessive worrying had to occur more days than not and on a number of different topics.<ref name="Craighead 2013" /> It has been stated that the constant changes in the diagnostic features of the disorder have made assessing epidemiological statistics such as prevalence and incidence difficult, as well as increasing the difficulty for researchers in identifying the biological and psychological underpinnings of the disorder. Consequently, making specialized medications for the disorder is more difficult as well. This has led to the continuation of GAD being medicated heavily with SSRIs.<ref name="Craighead 2013" />

See also

• Daily Assessment of Symptoms – Anxiety
• Mental health
• Mental health professional
• Psychotherapy
• Psychiatry

Sources

• Template:Cite journal

Further reading

• Brown, T. A., O'Leary, T. A., & Barlow, D. H. (2001). "Generalised anxiety disorder". In D. H. Barlow (ed.), Clinical handbook of psychological disorders: A step-by-step treatment manual (3rd ed.). New York: Guilford Press.
• Barlow, D. H., & Durand, V. M. (2005). Abnormal psychology: An integrative approach. Australia; Belmont, Calif.: Wadsworth.
• Template:Cite journal

External links

• Mayo Clinic – Information on diagnosis and treatment for GAD
• WebMD – Information on symptoms and causes of GAD
• Anxiety Disorders Association of America – Information for families, clinicians, and researchers
• National Institute of Mental Health, Generalized Anxiety Disorder: When Worry Gets Out of Control
• National Center for Complementary and Integrative Health, Anxiety and Complementary Health Approaches