Trajectories of improvement for six depression-related outcomes

Although depression treatment improves diverse outcomes, it is unclear whether these improvements are comparable in magnitude and timing. The objective was therefore to compare treatment-related improvements in depressive symptoms, work and social functioning, hopefulness, somatic complaints and positive well-being.

Secondary analysis of a large clinical trial of selective serotonin reuptake inhibitors for primary care depression. Depressed patients (n=573) from 37 practices from two primary care networks were randomized to fluoxetine, paroxetine or sertraline, and then followed naturalistically. At 1, 3, 6 and 9 months after treatment initiation, assessments were made of depressive symptom severity, social and work functioning, positive well-being, hopefulness beliefs and somatic complaints. Data were analyzed with linear regression modeling.

Although 68% and 88% of total mood improvement occurred by Months 1 and 3, respectively, improvement plateaued sooner for somatic complaints (P=.001 at Month 1), and more gradually for hopefulness [P (Month 1)=.015, P (Month 3)=.036]. Although magnitude of improvement was interrelated across outcomes, timing of mood improvement was unrelated to the timing of improvement in both somatic complaints and hopefulness. Improvement in somatic complaints was primarily attributable to improvements in head, back and stomach pain.

Work and social functioning, and positive affect improve synchronously with mood. Compared to mood, improvement in pain complaints peaks earlier, whereas improvement in hopefulness is much more linear over time. Because depression treatment response appears to be complex and multidimensional, a broader conceptualization of depression remission may be indicated.