The current social communication domain criteria for autism diagnosis require individuals to have deficits across three social skills: social-emotional reciprocity, nonverbal communication, and developing and sustaining relationships. Communication deficits are due to problems with social-emotional skills like joint attention and social reciprocity.A range of social-emotional reciprocity difficulties (an individuals ability to naturally engage in social interactions) may be present. Autistic individuals may lack mutual sharing of interests, for example many autistic children prefer not to play or interact with others. They may lack awareness or understanding of other peoples thoughts or feelings – a child may get too close to peers (entering their personal space) without noticing that this makes them uncomfortable. They may also engage in atypical behaviors to gain attention, for example a child may push a peer to gain attention before starting a conversation.Older children and adults with ASD perform worse on tests of face and emotion recognition than non-autistic individuals, although this may be partly due to a lower ability to define a persons own emotions.Autistic people experience deficits in their ability to develop, maintain, and understand relationships, as well as difficulties adjusting behavior to fit social contexts. ASD presents with impairments in pragmatic communication skills, such as difficulty initiating a conversation or failure to consider the interests of the listener to sustain a conversation. The ability to be focused exclusively on one topic in communication is known as monotropism, and can be compared to "tunnel vision".
They are common among children with ASD; there are no firm data, but studies have reported prevalences ranging from 11% to 84%. Many anxiety disorders have symptoms that are better explained by ASD itself, or are hard to distinguish from ASDs symptoms. Rates of comorbid depression in individuals with an ASD range from 4–58%. The relationship between ASD and schizophrenia remains a controversial subject under continued investigation, and recent meta-analyses have examined genetic, environmental, infectious, and immune risk factors that may be shared between the two conditions. Oxidative stress, DNA damage and DNA repair have been postulated to play a role in the aetiopathology of both ASD and schizophrenia. Deficits in ASD are often linked to behavior problems, such as difficulties following directions, being cooperative, and doing things on other peoples terms. Symptoms similar to those of attention deficit hyperactivity disorder (ADHD) can be part of an ASD diagnosis. Sensory processing disorder is also comorbid with ASD, with comorbidity rates of 42–88%. Starting in adolescence, some people with Asperger syndrome (26% in one sample) fall under the criteria for the similar condition schizoid personality disorder, which is characterized by a lack of interest in social relationships, a tendency towards a solitary or sheltered lifestyle, secretiveness, emotional coldness, detachment and apathy. Asperger syndrome was traditionally called "schizoid disorder of childhood." Genetic disorders - about 10–15% of autism cases have an identifiable Mendelian (single-gene) condition, chromosome abnormality, or other genetic syndromes. Several metabolic defects, such as phenylketonuria, are associated with autistic symptoms.