• Alcoholics have been proposed to be comprised of subtypes who differ in their age at onset and in type 1 vs type 2 characteristics. This study examined whether the clinical course of primary alcoholics was associated with age at onset as well as the type 1-vs-type 2 classification scheme. Interviews with 171 consecutive primary alcoholic men entering an alcohol treatment program revealed that age at onset of alcoholism was correlated with alcohol, drug, and childhood criminality problem histories. Neither classification of these alcoholics into discrete type 1 and type 2 categories nor placing them along a continuum of type 2 characteristics was consistently associated with severity of clinical histories. These findings underscore the clinical importance of age at onset and suggest the possibility that the type 2 prototype might represent a separate diagnosis, antisocial personality disorder, and not alcoholism itself.
Irwin M, Schuckit M, Smith TL. Clinical Importance of Age at Onset in Type 1 and Type 2 Primary Alcoholics. Arch Gen Psychiatry. 1990;47(4):320–324. doi:10.1001/archpsyc.1990.01810160020003