Antidepressant monotherapy: A claims database analysis of treatment changes and treatment duration.

BACKGROUND: The basic principles of pharmacotherapy for depression are consistent among most US and western European guidelines. All recommend ≥6 months of antidepressant therapy and propose several alternatives in cases of inappropriate response.
OBJECTIVES: The aims of this analysis were to describe antidepressant treatment changes and treatment duration in patients undergoing treatment for a new episode of depression and to identify risk factors for treatment changes and treatment discontinuation.
METHODS: For this claims database analysis, adults and children treated with antidepressants for a new episode of depression in the time period from 2004 to 2006 were identified using the IMS LifeLink Health Plan Database. Treatment changes (defined as switches to an antidepressant or antipsychotic; combination with an antidepressant; or augmentation with lithium, an anticonvulsant, or an atypical antipsychotic) were described. Antidepressant treatment duration was assessed and described per treatment change. Risk factors for treatment change or discontinuation were identified using multivariate logistic regression (treatment change) or Cox regression (treatment duration).
RESULTS: Of 134,287 patients identified using the database (mean [SD] age, 39.1 [14.9] years; 68.1% women), 31,123 (23.2%) had a treatment change, most commonly an antidepressant switch (12,735 [9.5%]) or combination (12,214 [9.1%]). Antipsychotics were introduced in <5% of patients. The median overall treatment duration (111 days) was shorter than that recommended in the guidelines (≥ 6 months). Index antidepressant class was significantly associated with treatment change (higher for tricyclic antidepressants [TCAs] [odds ratio (OR) = 1.59 (95% CI, 1.48-1.70)]; lower for selective serotonin reuptake inhibitors [OR = 0.87 (95% CI, 0.84-0.91)]) and duration (increased risk for early discontinuation for TCAs [hazard ratio (HR) = 1.36 (95% CI, 1.30-1.44)]; lower risk for late discontinuation for serotonin-norepinephrine reuptake inhibitors [HR = 0.81 (95% CI, 0.79-0.84)]). Indicators of depression severity or complexity (prescription by a mental health specialist, previous use of psychotropics, previous psychiatric hospitalization, and presence of psychosomatic comorbidities) were associated with a higher risk for treatment change and inconsistently associated with treatment duration. Two health plans were associated with increased risk for discontinuation (Medicaid, HR = 1.35 [95% CI, 1.28-1.42]; Medicare, HR = 1.38 [95% CI, 1.12-1.71]). Combination and augmentation strategies were associated with a lower risk for treatment discontinuation (combination, HR = 0.83 [95% CI, 0.81-0.86]; augmentation, HR = 0.75 [95% CI, 0.73-0.77]). Overall treatment duration was <30 days in 31,177 patients (26.2%) and >6 months in 54,502 (37.5%).
CONCLUSIONS: In this claims database analysis, changes in antidepressant treatment involved 23.2% of patients. The median overall treatment duration was shorter than recommended by guidelines due to a quarter of patients having early treatment discontinuation.