# What to target? Interventions to modulate key mechanisms underlying the trajectories of affective disorders in the transregional Collaborative Research Center 393

## TL;DR

This paper introduces a research project aiming to understand how to modify key mechanisms in affective disorders through targeted interventions.

## Contribution

It is the first study to investigate the modifiability of four key mechanisms in affective disorders both cross-sectionally and longitudinally.

## Key findings

- The study will examine modifiability of emotion regulation, expectation, social cognition, and cognitive-behavioral rhythms.
- Results will provide insights into how these mechanisms affect disease trajectories in affective disorders.

## Abstract

Affective disorders are associated with an enormous disease burden, necessitating research on the mechanisms of effective treatments.

This article introduces the intervention projects of the transregional Collaborative Research Center 393 (CRC/TRR 393). By employing targeted interventions, we aim to induce modifiability in the key mechanisms underlying the trajectories of affective disorders studied in CRC/TRR 393: emotion regulation, expectation, social cognition, and (circadian) cognitive–behavioral rhythms.

The longitudinal design of the CRC/TRR 393 study will examine four interventions targeting specific mechanisms in subgroups of the German Mental Health Cohort (GEMCO). GEMCO includes patients with a current or lifetime diagnosis of major depressive disorder (MDD), bipolar disorder (BD), and healthy control (HC) participants. Multilevel measurements of these targeted mechanisms will allow us to investigate their fine-grained modifiability and their effects on disease trajectories.

The results will provide insights into how these mechanisms can be modified. Together with the CRC/TRR 393 mechanisms projects, we will examine the effects of key cognitive–emotional mechanisms on disease trajectories.

For the first time, the modifiability of four key mechanisms underlying the trajectories of affective disorders will be investigated both cross-sectionally and longitudinally.

The online version of this article (10.1007/s00115-025-01929-0) contains an additional table.