Anchoring perceptions of clinical change on accurate recollection of the past: memory enhanced retrospective evaluation of treatment (MERET)

Psychiatry (Edgmont). 2007 Mar;4(3):39-45.


Objective: To evaluate patients' self-reports of treatment efficacy with and without self-prompted memory aids regarding their clinical experiences obtained prior to treatment initiation.

Design: Double-blind, placebo-controlled trial with variable expected duration placebo lead-in and washout.

Setting: Multisite (US) randomized clinical trial.

Participants: Seventy-four patients with initial or recurrent DSM-IV diagnosis of major depression with symptoms of at least four weeks duration. A minimum Clinical Global Impression of Severity rating of Moderately Depressed and a clinician 17-item Hamilton Rating Scale for Depression score of 15 or greater, with the depressed mood item score of at least 2 were required for study entry.

Measurements: Patient global impression of improvement (PGI-I) ratings obtained using an interactive voice response (IVR) computer-automated telephone system prior to and following playback of impromptu patient recordings obtained prior to the start of treatment (MERET).

Results: MERET PGI-I ratings differentiated the effects of drug treatment from placebo more effectively than did standard PGI-I ratings. The drug-placebo treatment effect size obtained using standard PGI-I ratings was 0.525, whereas the effect size with MERET PGI-I ratings was 0.612.

Conclusion: The enhanced drug-placebo separation appeared to be primarily due to increased patients' perceptions of drug treatment effectiveness. Patients perceiving the greatest degree of clinical improvement indicated more benefit from hearing the MERET recordings. MERET appears to be a viable method for enhancing patients' insights into the benefits of effective treatments by allowing them to use personal descriptions provided in their own words and voice.

Keywords: IVR; MERET; clinical trial; methodology; patient-reported outcomes.