Erwartungseffekte beim Absetzen von Antidepressiva: Implikationen für die Praxis

Study protocol: combined N-of-1 trials to assess open-label placebo treatment for antidepressant discontinuation symptoms [FAB-study]

BACKGROUND

Antidepressant discontinuation is associated with a broad range of adverse effects. Debilitating discontinuation symptoms can impede the discontinuation process and contribute to unnecessary long-term use of antidepressants. Antidepressant trials reveal large placebo effects, indicating a potential use of open-label placebo (OLP) treatment to facilitate the discontinuation process. We aim to determine the effect of OLP treatment in reducing antidepressant discontinuation symptoms using a series of N-of-1 trials.

METHODS

A series of randomized, single-blinded N-of-1 trials will be conducted in 20 patients with fully remitted DSM-V major depressive disorder, experiencing moderate to severe discontinuation symptoms following antidepressant discontinuation. Each N-of-1 trial consists of two cycles, each comprising two-week alternating periods of OLP treatment and of no treatment in a random order, for a total of eight weeks. Our primary outcome will be self-reported discontinuation symptoms rated twice daily via the smartphone application 'StudyU'. Secondary outcomes include expectations about discontinuation symptoms and (depressed) mood. Statistical analyses will be based on a Bayesian multi-level random effects model, reporting posterior estimates of the overall and individual treatment effects.

DISCUSSION

Results of this trial will provide insight into the clinical application of OLP in treating antidepressant discontinuation symptoms, potentially offering a new cost-effective therapeutic tool. This trial will also determine the feasibility and applicability of a series of N-of-1 trials in a clinical discontinuation trial.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT05051995, first registered September 20, 2021.

Disentangling pharmacological and expectation effects in antidepressant discontinuation among patients with fully remitted major depressive disorder: study protocol of a randomized, open-hidden discontinuation trial

BACKGROUND

Antidepressants are established as an evidence-based, guideline-recommended treatment for Major Depressive Disorder. Prescriptions have markedly increased in past decades, with a specific surge in maintenance prescribing. Patients often remain on antidepressants longer than clinically necessary. When attempting to stop, many patients experience adverse discontinuation symptoms. Discontinuation symptoms can be debilitating and hinder successful discontinuation. While discontinuation symptoms can result from pharmacological effects, evidence on nocebo-induced side effects of antidepressant use suggests that patients' expectations may also influence occurrence.

METHODS

To disentangle pharmacological and expectation effects in antidepressant discontinuation, patients with fully remitted Major Depressive Disorder who fulfill German guideline recommendations to discontinue will either remain on or discontinue their antidepressant. Participants' expectations will be manipulated by varying verbal instructions using an open-hidden paradigm. Within the open trial arms, participants will receive full information about treatment, i.e., high expectation. Within the hidden trial arms, participants will be informed about a 50% chance of discontinuing versus remaining on their antidepressant, i.e., moderate expectation. A total of N = 196 participants will be randomly assigned to either of the four experimental groups: open discontinuation (OD; n = 49), hidden discontinuation (HD; n = 49), open continuation (OC; n = 49), or hidden continuation (HC; n = 49). Discontinuation symptom load during the 13-week experimental phase will be our primary outcome measure. Secondary outcome measures include discontinuation symptom load during the subsequent 39-week clinical observation phase, recurrence during the 13-week experimental period, recurrence over the course of the complete 52-week trial evaluated in a time-to-event analysis, and stress, anxiety, and participants' attentional and emotional processing at 13 weeks post-baseline. Blood and saliva samples will be taken as objective markers of antidepressant blood serum level and stress. Optional rsfMRI measurements will be scheduled.

DISCUSSION

Until today, no study has explored the interplay of pharmacological effects and patients' expectations during antidepressant discontinuation. Disentangling their effects has important implications for understanding mechanisms underlying adverse discontinuation symptoms. Results can inform strategies to manage discontinuation symptoms and optimize expectations in order to help patients and physicians discontinue antidepressants more safely and effectively.

TRIAL REGISTRATION

ClinicalTrials.gov (NCT05191277), January 13, 2022.

Analgetische Placeboeffekte und Implikationen für die Behandlung chronischer Schmerzen

Die Behandlung von chronischen Schmerzen kann langwierig sein. Erste Ansätze zur Nutzung von Placeboeffekten bei der Behandlung von chronischen Schmerzen zeigen erfolgversprechende Ergebnisse und können dazu beitragen, die z. T. frustranen Therapieoptionen zu verbessern. Daher sollten Placeboeffekte zur verbesserten Behandlung genutzt werden. Im derzeitigen Modell zur Entstehung von Placeboeffekten spielt die Erwartung eine zentrale Rolle. Eine positive oder negative Erwartung wird durch psychologische und biologische „State“- und „Trait“-Faktoren der Patient:innen sowie die früheren Lernerfahrungen, die der:die Patient:in mitbringt, beeinflusst. Aus diesem Modell ergeben sich Implikationen für die klinische Praxis: Positive Erwartungen sollten unterstützt werden, wobei unrealistische Erwartungen wiederum den Placeboeffekt reduzieren. Negative Erwartungen sollten kritisch diskutiert werden. Es sollte im interdisziplinären Team eine gemeinsame Botschaft an die Patient:innen vermittelt werden. Open-Label-Placebos können als Intervention genutzt werden, um die Selbstwirksamkeit zu steigern.