Symptom-specific Temporal Phenotyping of Anti-depressant Response to Citalopram in STAR*D Trial

AbstractImportance: Depression treatments do not have equal potency for all depression symptoms. To inform research design and improve clinical care, it is critical to determine if these symptom-specific effects occur at different rates.Objective: To determine the symptom-specific time-to-improvement of depression symptoms during citalopram treatment.Design: The study uses STAR*D data, which prescribed citalopram as the first stage of an open-label, multi-stage clinical trial of stepwise treatment strategies for depression. This first stage typically lasted 12 weeks and follow-up assessments were, on average, every-other-week.Setting: Multi-centerParticipants: Over 4,000 adults aged 18-75 years diagnosed with Major Depressive Disorder without psychotic features participated in the STAR*D trial. Participants were prospectively enrolled patients in both primary and specialty care venues.Interventions: All participants started 20 mg/day of citalopram. If this dose was well tolerated, it could be increased to a maximum of 60 mg/day. Stage 1 typically lasted 12 weeks.Main Outcome(s) and Measure(s): This exploratory secondary data analysis focuses on change in the total score and each of the individual items, of the Quick Inventory of Depressive Symptomatology-SR.Results: 3,248 depressed adults were available for the present analyses (Mean age = 41 year (SD=13 years), 62% female)). The number of observations differed for each model. The median time for 1 standard deviation improvement in depression symptoms was 28 days. Median time for 1 point improvement (all possible thresholds are reported in text) varied widely for individual symptoms. The quickest improving symptom had a median-time-to-improvement of 15 days (increased weight) and the longest took 41 days (mid-nocturnal insomnia). The rank-order of which symptoms improved the quickest was highly consistent across models with different improvement thresholds (Spearman’s ρ = .66-.91, all p