Hypothesized neurochemical models for psychiatric syndromes in alcohol and drug dependence

Exploration of the neurochemistry of psychiatric and substance use disorders in dual diagnosis patients may help explain the greater than chance comorbidity of these disorders and lead to advances in treatment. This paper will focus on the hypothesized neurochemical changes associated with primary substance use disorders which might lead to secondary psychiatric disorders by mimicking the hypothesized neurochemical changes of primary psychiatric disorders. For example, hypothesized serotonergic deficits in alcoholism, endorphin deficits in opioid dependence, and dopamine depletion in cocaine dependence all might predispose to depression. A vicious cycle of cocaine dependence and depression and a vicious cycle of alcohol and drug dependence and panic anxiety are reviewed as models for hypothesized alcohol or drug withdrawal related neurochemical changes predisposing to continued chemical dependency. Exploration of the neurochemistry of dual diagnosis patients reinforces the need for treatment approaches that take into account both aspects of illness.