Efficacy Issues With Antidepressants

Clinical trials of antidepressant medications have shown that, overall, these drugs are effective, asmeasured by a ≥ 50% decrease in Hamilton Rating Scale for Depression (HAM-D) total scores inabout two thirds of patients. However, the results of long-term trials under rigorously controlled conditionsshow that, even with close follow-up and provision of interpersonal psychotherapy, a third ormore of the patients will not achieve or maintain a response to medication for depression. Nevertheless,the improved efficacy of some antidepressants for certain features or types of depression hasbeen shown. Factors associated with a better response to a specific agent or class of drugs includeseverity of symptoms, patient age, and the symptom profile of the depressive episode, as revealed byassessment scales or subscale scores for selected symptoms. Moreover, a number of studies indicatethat a patient’s early response to a given medication may assist in predicting long-term outcome.However, outcome measures in traditional trials of antidepressant drug efficacy, such as a 50% reductionin scores on one or more depression rating scales, do not necessarily reflect an improvement inthe patient’s ability to function in the workplace; they only show that a particular patient at a particulartime has responded to treatment in a significant manner by measurement of a depression scale.