Differential diagnosis and psychopharmacology of dual disorders.

There are multiple potential interactions of substances of abuse with psychiatric illnesses. The individual agents, the stage of abuse, withdrawal, or recovery, and the patient's psychiatric illness must be considered as an integrated whole to ascertain the appropriate interventions. Polysubstance abuse can cause still more complicated interactions. Assessment of differential treatment needs for both the psychiatric illness component and the substance use disorder component permits both elements to be approached, often simultaneously, and can facilitate treatment of both. Ignoring either component can lead to inappropriate treatment or exacerbation of illness. The high rate of comorbidity of chemical dependence and other psychiatric illnesses is intriguing in light of studies that demonstrate vulnerability to drug abuse associated with specific alleles of the dopamine D2 receptor gene in some families. It is hoped that further investigations will shed light on the complex interactions and associations between chemical dependency and other psychiatric illnesses and result in new treatment strategies for both. In the past, many substance abuse treatment programs used to emphasize the complete cessation of all medications including some potentially beneficial prescription medications. This was likely because of previous excessive prescription by physicians of sedatives or benzodiazepines. Increasingly, recovery programs support intelligent, responsible use of nonaddictive psychiatric medications, and AA World Services prints a pamphlet supporting such physician-supervised use. Conversely, psychiatrists previously frequently overlooked or neglected diagnosis and treatment of chemical-dependency disorders. Greater efforts are needed to focus equal energy on diagnosis and treatment of chemical-dependency disorders in "psychiatric" populations. Many studies show that physicians neglect to collect adequate information and are not sufficiently aggressive in referring patients to chemical dependence treatment programs. By combining knowledge and appropriate therapeutic interventions from both psychiatric and addiction treatment fields, the needs of the dually diagnosed patient can be met more adequately.