Article Summary
Clinical Summary: Early Improvement as a Predictor of Treatment Response in Patients With Obsessive-Compulsive Disorder: A 12-Week Randomized Trial of Sertraline and Fluvoxamine
When starting an SSRI for obsessive-compulsive disorder, clinicians often wait 12 weeks before deciding whether the trial has worked, even though delayed improvement prolongs symptoms and uncertainty for patients. This study asks a practical question: can symptom change early in treatment identify who is likely to respond by 12 weeks, and does that differ between sertraline and fluvoxamine?
Design
This was a randomized, open-label, prospective, intent-to-treat study comparing sertraline and fluvoxamine in patients with OCD.
N
A total of 50 patients aged 18–55 years who consented to participate were enrolled in the study.
Population
Drug-naive patients with OCD, diagnosed per DSM-5 criteria, visiting the walk-in clinic of the department of psychiatry for the first time were approached.
Duration
The study period of 12 weeks
Key Findings
- Of the total sample, 60% (n = 30) of patients showed early response at 4 weeks, defined as ≥ 20% reduction in YBOCS score; of those responders, 93.3% showed a response at the end of 12 weeks (Pearson χ2 = 16.93, P = .000).
- Early response predicted response at 12 weeks with 77.8% sensitivity and 85.7% specificity.
- The number of responders was significantly higher in the fluvoxamine group compared to the sertraline group at 12 weeks (Pearson χ2 = 6.349, P = .012).
- Among the 40% (n = 20) of patients who did not show an early response, 8 showed a response at the end of 12 weeks.
- The mean YBOCS score (N = 50) after 12 weeks of treatment was 12.88, which showed a statistically significant reduction in the severity score (P = .000), while the reduction in mean YBOCS scores across 12 weeks in both drug groups (sertraline group = 13.80, fluvoxamine group = 11.96) was statistically insignificant (P = .443).
Clinical Bottom Line
A ≥ 20% YBOCS reduction by 4 weeks after reaching a minimum therapeutic SSRI dose strongly identifies patients likely to respond by 12 weeks. In this drug-naive OCD sample, fluvoxamine yielded a higher categorical response rate than sertraline, despite no significant between-drug difference in mean YBOCS reduction.
Practice Implications
- Reassess OCD symptoms after 4 weeks at a minimum therapeutic SSRI dose using YBOCS, because early improvement was linked to 12-week response with 77.8% sensitivity and 85.7% specificity.
- Do not assume early nonresponse rules out later benefit: 40% (n = 20) did not improve early, and 8 of those patients still responded by 12 weeks.
- When choosing an initial SSRI for a drug-naive patient with OCD, consider fluvoxamine if maximizing likelihood of categorical response is the priority, while also discussing its higher mean per month cost of 2,790 Indian rupees (US$ 37.41) versus 1,284 Indian rupees (US$ 17.22) for sertraline.
- Dose optimization matters: the average minimum dose achieved at the end of the induction period was 95 mg/d for sertraline and 102 mg/d for fluvoxamine, and the mean maximum tolerable therapeutic doses were 196 mg/d and 284 mg/d, respectively.
