Psychotherapy and pharmacotherapy in depression.

BACKGROUND Depression is a condition with various modes of treatment, including pharmacotherapy, psychotherapy, and some combination of each. The role of psychotherapy in the treatment of depression relative to the role of pharmacotherapy is not well understood, and guidelines for psychotherapy in the primary care setting differ from guidelines for specialty care. There is little evidence concerning circumstances in actual practice that affect the use of psychotherapy in conjunction with pharmacotherapy. AIMS OF THE STUDY We retrospectively identify the most important factors associated with the use of psychotherapy in combination with pharmacotherapy in the treatment of depression. Specifically, we study provider choice, health plan characteristics, and patient characteristics. METHODS We use a comprehensive medical and pharmacy claims data sample of 1,023 individuals during 1992 1994. We select persons prescribed with an antidepressant medication and diagnosed with a depressive disorder by a primary care physician, psychiatrist, or non-physician mental health specialist. Controlling for depression diagnosis, comorbidity, and demographics, we examine the role of provider type and insurance plan benefit characteristics. We study the intensity of psychotherapy using zero-inflated count regression, the intensity of pharmacotherapy using truncated count regression, and the likelihood of treatment failure using logistic regression. RESULTS Patients initially seeing a psychiatrist receive more than double the amount of psychotherapy and slightly more pharmacotherapy than patients of other providers. An additional prescription for antidepressant medication reduces by five percent the likelihood of treatment failure, but the amount of psychotherapy does not affect treatment failure. Patients seeing a psychiatrist are half as likely to have failed treatment, independent of any effect of psychotherapy. Case management and coinsurance rates do not affect the amount of psychotherapy, but the presence of case management positively affects the amount of pharmacotherapy and the likelihood of treatment failure. DISCUSSION Although the amount of psychotherapy provided in conjunction with medication does not lower the rate of treatment failure, psychotherapy may nonetheless provide beneficial outcomes not studied here. Choice of a psychiatrist reduces the likelihood of treatment failure, independent of the number of psychotherapy sessions and antidepressant prescriptions. The effect of provider choice on treatment failure could be an artefact of differences in provider follow-up practices or could represent a difference in provider skills. Managed care strategies do not appear to reduce the intensity of depression treatment, but case management does increase the likelihood of treatment failure. IMPLICATIONS FOR HEALTH CARE PROVISION Combined treatment with pharmacotherapy and psychotherapy appears to be individualized, as there is no pattern of more or less psychotherapy associated with antidepressant medication use. Choice of psychiatrist as the initial provider appears to reduce the likelihood of treatment failure, suggesting coordinated care may be beneficial. The link between psychiatrists and more psychotherapy is consistent with the hypothesis that patients resistant to treatment may nonetheless receive high quality care. IMPLICATIONS FOR HEALTH POLICIES Managed care tools such as case management and coinsurance rates do not appear to restrict the use of either psychotherapy or pharmacotherapy. The association of case management with an increased likelihood of treatment failure suggests that plan characteristics can affect outcomes. IMPLICATIONS FOR FURTHER RESEARCH Our study focuses on psychotherapy combined with medication and does not consider psychotherapy alone in the treatment of depression, which may be a preferred mode of treatment for some. Outcomes other than treatment failure, as well as costs, should also be considered. Our findings that psychiatrists are associated with a decreased likelihood of treatment failure and that case management is associated with an increased likelihood of treatment failure despite a correlation with greater pharmacotherapy intensity present avenues for additional study.