Many alcoholics present with depressive symptoms. The majority of depressive symptoms are substance induced. Depressive symptoms in the context of independent and induced depressions are very similar. Independent and induced depressions breed true. The depressive symptoms are temporary.
Children of alcoholics show no increase in major depressive episodes.
Similar data can be given regarding bipolar disorders. It is essential to distinguish between acute or protracted withdrawal related overactivity versus true mania. Even after controlling for these factors, however, there is a greater than chance relationship between independent bipolar disorder and substance dependence. There are a number of potential explanations for this relationship, including genetic factors. V. Similar conclusions can be drawn regarding the major anxiety disorders.