Frequently Asked Questions

Yes. In this 12-week randomized study of 50 drug-naive patients with OCD, early improvement predicted 12-week response with 77.8% sensitivity and 85.7% specificity. Early improvement was defined as a 20% or greater reduction in Yale-Brown Obsessive-Compulsive Scale (YBOCS) score, and final response was defined as a 35% or greater reduction in YBOCS score at 12 weeks.

Early improvement was observed at 4 weeks after achieving the minimum therapeutic dose. In the study protocol, patients started at 50 mg/day, doses were escalated over a 2-week induction period to at least a therapeutic dose, and early response was then assessed during the following 4 weeks using a 20% or greater reduction in YBOCS score.

Sixty percent of patients (30 of 50) showed early response, defined as a 20% or greater reduction in YBOCS score at 4 weeks after reaching the minimum therapeutic dose. The number of early responders was comparable between the sertraline and fluvoxamine groups.

In this study, patients with early improvement were very likely to respond by 12 weeks. Of the 30 patients who showed early response, 93.3% met the study's 12-week response criterion of a 35% or greater reduction in YBOCS score (Pearson χ2 = 16.93, P = .000).

No. Although early improvement was predictive, lack of early response did not rule out later benefit. In this study, 40% of patients (20 of 50) did not show early response, and 8 of those 20 patients still met response criteria by 12 weeks.

The study found a mixed result. Fluvoxamine had a significantly higher categorical response rate than sertraline at 12 weeks (Pearson χ2 = 6.349, P = .012), but the reduction in mean YBOCS scores between the 2 groups was not significantly different (sertraline 13.80 vs fluvoxamine 11.96 at 12 weeks, P = .443).

Yes. The authors reported that both medications had similar side effect profiles and concluded that sertraline and fluvoxamine were equally well tolerated in this sample of drug-naive patients with OCD.

Participants in both groups started at 50 mg/day. By the end of the 2-week induction period, the average minimum dose reached was 95 mg/day for sertraline and 102 mg/day for fluvoxamine. The mean maximum tolerable therapeutic doses later reached were 196 mg/day for sertraline and 284 mg/day for fluvoxamine.

Across the full sample, OCD severity improved significantly over 12 weeks. The mean baseline YBOCS score was 23.48 ± 6.29, and the mean YBOCS score at 12 weeks was 12.88, a statistically significant reduction (P = .000).

No. The study found no significant difference in sociodemographic or clinical characteristics between early responders and early nonresponders. In this sample, short-term symptom change was more informative than baseline patient characteristics for estimating 12-week outcome.

This study suggests that a full 12-week wait may not be necessary for all patients. The authors concluded that if a patient does not show early improvement after 4 weeks at a minimum therapeutic SSRI dose, a long 12-week drug trial may not be warranted in all cases, although some early nonresponders still improved by week 12.

The main limitations were a small sample size and the coincidental inclusion of more patients with moderate severity of illness. The authors stated that larger studies are needed before revising current treatment expectations for OCD.