Editing Pervasive developmental disorder (section)

==Signs and symptoms==
Symptoms of PDD may include behavioral and communication problems such as:
* Difficulty using and understanding language<ref name="NINDS"/>
* Difficulty relating to people, objects, and events;<ref name="NINDS"/> for example, lack of eye contact, pointing behavior, and lack of facial responses
* Unusual play with toys and other objects.<ref name="NINDS"/>
* Paranoia, a characteristic form of social anxiety, derealization, transient psychosis, and unconventional beliefs if environment or routine are changed without notice<ref name="NINDS"/>
* [[Stereotypy|Repetitive body movements]] or behavior patterns,<ref name="NINDS"/> such as hand flapping, hair twirling, foot tapping, or more complex movements<ref name=":0">{{Cite journal |last1=Baird |first1=G. |last2=Douglas |first2=H. R. |last3=director |first3=a. |last4=Murphy |first4=M. S. |date=2011-10-21 |title=Recognising and diagnosing autism in children and young people: summary of NICE guidance |url=https://www.bmj.com/lookup/doi/10.1136/bmj.d6360 |journal=BMJ |language=en |volume=343 |issue=oct21 1 |pages=d6360 |doi=10.1136/bmj.d6360 |pmid=22021468 |s2cid=31196910 |issn=0959-8138|url-access=subscription }}</ref>
* Difficulty regulating behaviors and emotions, which may result in temper tantrums, anxiety, and aggression<ref name=":0" />
* Emotional breakdowns{{citation needed|date=August 2021}}
* Delusional or unconventional perception of the world{{citation needed|date=August 2021}}
* [[Maladaptive daydreaming]]{{citation needed|date=August 2021}}

===Degrees===
Children with PDD vary widely in abilities, intelligence, and behaviors. Some children do not speak at all, others speak in limited phrases or conversations, and some have relatively normal language development. Repetitive play skills and limited social skills are generally evident. Unusual responses to sensory information—loud noises, lights—are common.<ref name="NINDS"/>