In situ fNIRS measurements during cognitive behavioral emotion regulation training in rumination-focused therapy: A randomized-controlled trial

Abstract

Repetitive negative thinking (RNT), including rumination, plays a key role in various psychopathologies. Although several psychotherapeutic treatments have been developed to reduce RNT, the neural correlates of those specific treatments and of psychotherapy in general are largely unknown. Functional near-infrared spectroscopy (fNIRS) offers the potential to investigate the neural correlates of psychotherapeutic techniques in situ. Therefore, in this study we investigated the efficacy and neural correlates of a fNIRS adapted Mindfulness-based Emotion Regulation Training (MBERT) for the treatment of depressive rumination in 42 subjects with major depressive disorder (MDD) in a cross-over designed randomized controlled trial. Using psychometric measures, subjective ratings and fNIRS, we analyzed in situ changes in depressive symptom severity, ruminative thoughts and cortical activity in the Cognitive Control Network (CCN). Our results show that MBERT is effective in treating depressive symptoms and rumination. On a neural level, we found consistently higher cortical activation during emotion regulation training compared to control trials in the bilateral inferior frontal gyrus (IFG) and dorsolateral prefrontal cortex (DLPFC). Furthermore, cortical oxygenation decreased from session to session in the bilateral DLPFC. The relevance of the results for the psychotherapeutic treatment of MDD as well as further necessary investigations are discussed.

Trial registration: ClinicalTrials.gov NCT04560192.

Keywords: Emotion Regulation; In situ measurements; Major Depression; Psychotherapy; Repetitive Negative Thinking (RNT); functional near-infrared spectroscopy (fNIRS).

Fig. 1

Flow of participants. Note. TSST = non-willingness to participate in another stress paradigm later in the study. ^aOne participant demanded all collected data to be deleted. ^bTwo patients did not complete the whole study procedure but participated in all eight therapeutic training sessions, so their data could be used in some of the conducted analyses.

Fig. 2

Study design of the project. Note. BDI-II = Beck-Depressions-Inventar II (Hautzinger et al., 2009). SWE = Skala zur Allgemeinen Selbstwirksamkeitserwartung (Jerusalem and Schwarzer, 2003). SCS = The Self-Compassion Scale (Hupfeld & Ruffieux, 2011). SRQ = state rumination questionnaire (see supplementary material). TAU = Treatment as usual. t₁, t₂, t₃ = measurement points of the Trier Social Stress Test (TSST).

Fig. 3

Procedure of the trials in the MBERT.

Fig. 4

Changes in depressive symptom severity (4a), self-efficacy (4b), self-compassion (4c) and ruminative thoughts (4d) in the course of the study participation, differentiated by group (treatment vs. TAU). Small brackets symbolize significant group differences.

Fig. 5a

Overall amount of given therapeutic interventions.

Fig. 5b

Amount of therapeutic interventions/instructions, differentiated by sessions and session phases.

Fig. 6

Changes in subjective rating means over sessions and session phases.

Fig. 7

Activation maps for the experimental contrast (training vs. rest) for the different sessions (S1 to S8; top to bottom). Differences are plotted as effect sizes in Cohen's d. Warm colors indicate higher activation during training trials, while cold colors indicate higher activation in rest trials.