How Do Doctors Define Autism?
The DSM-5 defines 3 main characteristics as necessary for diagnosing autism. These are deficits in socio-emotional reciprocity, which refers to deficits in conversations and social interactions, non-verbal communication, which include hand gestures and eye contact, and deficits in relationships, which includes making friends.
Outside of these 3 main characteristics, there are 4 symptoms that often accompany autism. However, a patient does not need all 4 to qualify as autistic. By definition, patients need to show at least two of these four symptoms, either currently or in the past, to qualify as having Autism Spectrum Disorder.
The Diagnostic Statistical Manual is the most commonly used manual for diagnosing psychiatric disorders and conditions. Since psychiatric disorders are often not well defined by an underlying cause, manuals like these are used to define what consistitutes a disorder and what is normal behavior.