“Antisocial behavior” is a very broad term encompassing acts ranging in severity from misdemeanors such as petty theft to murder. Thus a specific role for neurochemical or neuroendocrine factors certainly cannot be postulated or elucidated to explain such behavior in its entirety. Even when the term “antisocial” is used in other than a legal or criminological sense – for example, when it is applied in psychiatric diagnostics in an attempt to define and understand individual human behavior more fully – it remains overinclusive. From a clinical standpoint, the term “antisocial” most often signifies antisocial personality disorder (American Psychiatric Association, 1952, 1968, 1980), which in the third edition of the American Psychiatric Association's Diagnostic and Statistical Manual of Mental Disorders (DSM-III) is considered an “axis II” personality disorder, which may or may not coexist with certain “axis I” clinical syndromes or other conditions. Simply stated, this means that, according to current diagnostic nomenclature, an antisocial personality disorder theoretically could coexist with an organic mental disorder, substance use disorder, paranoid disorder, depressive disorder, psychosexual disorder, and so on.

For the diagnosis of antisocial personality disorder, the individual must be at least 18 years old and have a history, before the age of 15, of three or more symptoms that include truancy, expulsion or suspension from school, delinquency, running away, lying, substance abuse, thefts, vandalism, fights, and so on.