TNAD are not simply treated alcoholics observed early in their alcohol use histories but, rather, come from a different population than (later) treated alcoholics. In fact, they drank 50% less than long-term abstinent treated alcoholics (LTAA) in the period immediately after meeting criteria for heavy drinking (Fein and Landman, 2005). They have a lower family history density of alcohol problems than do LTAA (di Sclafani et al., 2008). They have less psychiatric comorbidity than LTAA, but more comorbidity than NAC (di Sclafani et al., 2008). TNAD showed less severe brain structural differences from NAC than do LTAA samples, with the primary finding in TNAD being a greater age-related decline in cortical gray matter when compared to non-alcoholic controls (Fein et al., 2002).
