Despite the importance of medications in modern mental health treatment, the therapeutic potential of the clinician-patient interaction itself may prove to be the single most effective tool available to the primary health care provider. Regardless of variations in training and clinical strengths, primary care providers have opportunities for roles in mental health treatment in four areas. These are the evaluation and treatment of psychiatric illness; interim medication review and refills for stable patients, in cooperation with the prescribing psychiatrist; the use of appropriate pharmacologic interventions in the treatment of conditions commonly associated with mental health symptoms (cocaine withdrawal, chronic pain); and the prevention of avoidable decompensation through the use of nonpharmacologic interventions. In additional areas such as sleep disturbance and situational anxiety, the use of pharmacological treatments remain controversial. 3 references (Author abstract modified)