Initial Antidepressant Therapy Research Articles

Partial Response and Nonresponse to Antidepressant Therapy

Response to antidepressant drug therapy is less than optimal for a considerable proportion of depressed patients; at present, however, few data exist to guide their rational therapeutic management. This review describes general principles for the management of such patients. This review is the result of an expert roundtable meeting convened to review published clinical data and clinical experience and provide clinicians with evidence-based principles on the management of patients who fail to respond optimally to initial antidepressant therapy. Failure to respond may be defined as a < 25% decrease on an accepted symptom rating scale such as the Montgomery-Asberg Depression Rating Scale (MADRS) or the Hamilton Rating Scale for Depression (HAM-D) in a patient who has received an adequate dosage for 4 weeks. In these patients, a neuropharmacologic rationale exists to switch to an agent with a different mode of action or a dual action. Partial response may be defined as 6 to 8 weeks at an adequate dosage and 25% to 50% decrease in MADRS or HAM-D score. In these patients, dose escalation should be considered, followed by augmentation and switching strategies. For augmentation, knowledge of neuropharmacology may allow prediction of which second agent will potentiate or complement the action of the first agent; it may also permit the prediction of potential safety concerns. On the basis of a review of the medical literature and clinical experience regarding patients with partial response or nonresponse to antidepressant drug therapy, it appears that simultaneous targeting of both the noradrenergic and serotonergic systems is one of the most effective augmentation strategies. Switching to an agent of a different class is probably optimal for those patients who fail to respond to first-line therapy.

SSRI antidepressant use patterns and their relation to clinical global impression scores: a naturalistic study

Background: A cascade of events follows initial antidepressant selection which includes the subsequent antidepressant use pattern, resultant clinical outcomes, and associated health care expenditures. Purpose: The purpose of this study using data from a clinical practice setting was to test whether the pattern of antidepressant use was correlated with patients' treatment response as measured by the score on the Clinical Global Impression-Improvement scale. Data and Methods: A retrospective dataset of patients who initiated therapy on fluoxetine, fluvoxamine, paroxetine, or sertraline in a primary care setting in Spain was used. A Cox proportional hazard analysis was used to predict the likelihood of treatment response based upon the pattern of initial antidepressant use, while minimizing the influence of other factors. Results: After controlling for other observed baseline characteristics including initial disease severity, (a) patients who remained on their initial antidepressant therapy for at least 2 months with no switching, augmentation, or upward dose titration were 1.63 times more likely to experience a treatment response than patients who had an adjustment to therapy; and (b) patients who initiated therapy on sertraline were 0.46 times as likely to experience a treatment response as patients who initiated therapy on the most common study antidepressant, fluoxetine. Conclusion: The pattern of antidepressant use is an important determinant of treatment response among patients initiating therapy on the newer antidepressants in clinical practice.

MHA4 SSRI Antidepressant Use Patterns and their Relation to Clinical Global Impressions Scores: A Naturalistic Study

Previous studies of antidepressants in clinical practice have established a link between initial antidepressant selection and patterns of antidepressant use and health care expenditures. However, there has been far less research to date demonstrating a link between the patterns of antidepressant use and patients' clinical outcomes using data from actual clinical practice. OBJECTIVE: The purpose of this study using data from a clinical practice setting was to test whether the pattern of antidepressant use was correlated with patients' treatment response as measured by the score on the Clinical Global Impressions-Improvement scale. DATA AND METHODS: A dataset of patients who initiated therapy on one the most common selective serotonin reuptake inhibitors (SSRLs) fluoxetine, fluvoxamine, paroxetine, or sertaline in a general practitioner setting in Spain was used. A Cox proportional hazard analysis was used to predict the liklihood of treatment response based upon the pattern of initial antidepressant use, while controlling for the influence of other baseline characteristics. RESULTS: After controlling for other observed baseline characteristics including initial disease severity, patients who remained on their initial antidepressant therapy for at least two months with no switching, augmentation, or upward dose titration were 63.2% more likely (p < 0.05) than patients who had an adjustment to therapy to exprience a treatment response. CONCLUSION: The pattern of antidepressant use is an important determinant of treatment response among patients initiating therapy on the newer antidepressants in clinical practice.