A randomized controlled outcome and follow-up study of Mann's time-limited psychotherapy.

Thirty-three patients were assessed for suitability for time-limited psychotherapy (TLP). A battery of outcome measures was composed of patient self-report measurements and objective judgments by external ("masked") raters. Patients were randomly assigned to either the experimental group, which received TLP immediately, or the control group, whose TLP was delayed for 3 months. Patients were evaluated on outcome measures at TLP termination and again at 6 and 12 months after termination. Significant improvement was observed in the experimental group after TLP, but the control patients did not show any systemic changes after waiting. However, after TLP, the control patients improved significantly. The average effect size measured by the differences between gain scores of the experimental patients (before vs. after treatment) and those of the control patients (before vs. after waiting) was 0.986 SD. The gains achieved after therapy were stable in both groups after 6- and 12-month follow-ups.