Remission is spontaneous in about 20% of people with alcohol dependence, who achieve long term sobriety without active treatment (DSMIV 1994). Gender and age do not substantially affect prognosis. Positive prognostic factors are good social functioning (employment, family relationship, absence of legal problems) and good health status. Retention in treatment for at least one month increases the likelihood of remaining abstinent for one year (Hales 1999). Psychiatric comorbidity is a negative prognostic factor.