[5] Starting in 1928 he published a series of studies conducted at The Sheppard and Enoch Pratt Hospital in Baltimore on the 'psychopathic personality' — a broad category used somewhat differently from some predominant definitions today.
"[7] In a 1930 review from the Research Service of the Sheppard and Enoch Pratt Hospital, Partridge identifies confusion in the definition and application of the diagnosis of psychopathy, as at the time the term could cover almost any kind of personality deviation acutely or chronically, or only certain more specific conditions, or act virtually as a holder for any otherwise unclassified mental disorder.
He also argues that the practice, then common, of calling psychopathy "constitutional" was speculative (in fact very little being known about its causes); and that bisecting personality into the "normal" and "abnormal" is simplistic for something complex, finely nuanced, and individual.
[12] The American Psychiatric Association created a diagnosis of "Sociopathic Personality Disturbance" in the first edition of its Diagnostic and Statistical Manual of Mental Disorders in 1952, which included four subtypes dubbed "reactions": antisocial, dyssocial, sexual, and addiction.
In 1976 psychiatrist Richard L. Jenkins (who wrote the child and adolescent behavioral disorders section of the DSM-II) pointed out that although sociopathy had become widely used as a diagnosis, it was not a diagnostic term per se in the DSM-I or II.
Nevertheless, the term psychopath gradually came into wider clinical use, partly through the influence of Canadian psychologist Robert D. Hare's Psychopathy Checklist, which revived and modified Cleckley's criteria in a criminological context.
Both the DSM-IV and DSM-5 noted: "The essential feature of antisocial personality disorder is a pervasive pattern of disregard for, and violation of, the rights of others that begins in childhood or early adolescence and continues into adulthood.