Improving Treatment of Severe Major Depressive Disorder by Reducing Negative Future-Oriented Mental Imagery

Patients with major depressive disorder (MDD) often do not sufficiently benefit from treatment. That is, around 50% of patients with MDD do not respond to treatment and 20-30% only achieve partial remission. Future-oriented negative mental imagery (e.g., mental images of suicide or own funeral) is likely an important maintaining factor of depression and initial studies in depression indicate that targeting mental imagery with 'imagery rescripting' could be a promising therapeutic technique to reduces depressive symptomatology by targeting these images directly that elicits strong affects/emotions and depressive symptomatology.

Before testing the (cost)effectiveness of future-oriented imagery rescripting to treatment as usual (TAU), a pilot study is needed to examine 1) the acceptability of the intervention, 2) the feasibility of the study, and 3) the variance of effect on reducing depressive symptomatology that can serve as estimate of the sample size for a follow-up randomized controlled trial (RCT).

A multicenter pilot RCT with a mixed factorial design with three time points (i.e., baseline, post-treatment, and follow-up of 3 months) will test 50 patients with MDD who will be randomly allocated to future-oriented imagery rescripting plus TAU or TAU only.

The sample consists of adult patients of 18 years or older with an MDD diagnosis.

All patients in this pilot study receive TAU, which involves a combination of pharmacological and psychological interventions. Half of the patients will also receive 3-5 sessions of future-oriented imagery rescripting (ImRes). In each ImRes session, patients identify an image of a autobiographic catastrophic future event (e.g., catastrophic images of future suicide or the loss of work or a loved one). They are subsequently asked to "rescript" this image into a more benign one.

The primary aim of this pilot study is to determine the acceptability of the intervention. The secondary aims are to elucidate factors that may facilitate or hinder the feasibility of the follow-up RCT (e.g., recruitment process) and to estimate the variance of the effect on reduction of depressive symptomatology, which informs the sample size calculation of the follow-up RCT. To study acceptability, the investigators assess depressive symptoms (BDI-II and BADS) and treatment satisfaction (SRS and CSQ-8). To measure feasibility, the investigators will assess recruitment/admission ratio, dropout and (serious) adverse events. Finally, to estimate the variance of effects, group effects on the BDI-II will be tested at post-treatment and follow-up (corrected for baseline).

Imagery rescripting on negative memories has already proven effective and safe in MDD patients. There is no known major risk associated with study participation. Patient burden comprises an online or phone-based screening interview of maximum 60 minutes and several questionnaires. Participants receive a reimbursement of €25,- after study completion (i.e., after follow-up assessment). The project will contribute to improving the care for patients with MDD. If the results show that the intervention is feasible and acceptable, this pilot study will inform the setup of the main RCT on the (cost)effectiveness of the intervention (ZonMW).