Onset and staging of DSM-IV alcohol dependence using mean age and survivalazard methods.

Orderly onset of psychiatric symptoms has implications for both case detection and the construct validity of the underlying illness. Mean age and survival-hazard techniques were used to study the onset of alcohol abuse and dependence (as defined in the 4th edition of the Diagnostic and Statistical Manual of Mental Disorders; American Psychiatric Association, 1994) in 369 clinical cases drawn from a heterogeneous regional sample. The methods provided a similar general pattern of symptom sequencing, though only survival-hazard analysis described a punctuated onset of alcoholism in 3 discrete stages: alcohol abuse, dependence, and accommodation to the illness. This model survived a rigorous program of tests for goodness of fit and described the majority of the sample, supporting the construct validity of both alcohol abuse as a discrete first illness phase and of dependence as a set of core constructs distinct from and succeeding abuse. The specific strengths of survival-hazard analysis as a research tool in illness staging research are discussed.