Insights from a laboratory and naturalistic investigation on stress, rumination and frontal brain functioning in MDD: An fNIRS study

Fig. 1. Time course of the TSST. BADO = Social Demographic Data, BDI = Beck Depression Inventory II, RRS = Rumination Response Scale, FEEL-E = Questionnaire to assess emotion regulation strategies, LSAS = Liebowitz Social Anxiety Scale, PANAS = Positive and Negative Affect Schedule, VAS = Visual Analogue Scale assessing the subjective stress ratings, SRQ = state rumination questionnaire, RSQ = resting-state questionnaire, CTL1 = Control Task 1/reading numbers, CTL2 = Control Task 2/calculations without social stress. BADO, BDI and RRS were only assessed at the first measurement date, FEEL-E and LSAS at the second measurement date. Participants got debriefed only after completion of both measurements.

Fig. 2. Time course of the SECPT. BADO = Social Demographic Data, BDI = Beck Depression Inventory II, RRS = Rumination Response Scale, FEEL-E = Questionnaire to assess emotion regulation strategies, LSAS = Liebowitz Social Anxiety Scale, PANAS = Positive and Negative Affect Schedule, VAS = Visual Analogue Scale assessing the subjective stress ratings, SRQ = state rumination questionnaire, RSQ = resting-state questionnaire. BADO, BDI and RRS were only assessed at the first measurement date, FEEL-E and LSAS at the second measurement date. Participants got debriefed only after completion of both measurements.

Fig. 3. Cortisol and heart rate in response to the TSST and SECPT. Heart rate in beats per minute (bpm) dependent on condition and group in the TSST (A.1/2) and the SECPT (B.1/2). Error bars indicate standard errors. *p < .05, **p < .01,***p < .001. CTL = control task, anti = anticipation phase, inter = job interview, arit = arithmetic task, rest = resting state.

Fig. 4. Subjective stress ratings assessed with the Visual Analogue Scale (VAS) dependent on condition and group in the TSST (A) and SECPT (B). Error bars indicate standard errors. *p < .05, **p < .01,***p < .001, comparisons in both graphs are related to differences between time points.

Fig. 5. Negative affect assessed by the PANAS dependent on condition and group in the TSST (A.1) and SECPT (B.1). State rumination dependent on condition and group in the TSST (A.2) and SECPT (B.2). Error bars indicate standard errors. *p < .05, **p < .01,***p < .001.

Fig. 6. Boxplots indicating the percentage of triggers of rumination over the two weeks of EMA assessment dependent on group (MDD = depressed patients, HC = healthy controls). Note that only the three triggers significantly differing in their occurrence between the groups were depicted. No events = average number of reporting no stressful event per subject, interactions = average number of social interactions that led to stress per subject, internal = average number of internal events (e.g. thoughts, emotions) that led to the experience of stress per subject.

Fig. 7. Correlation of the TSST- (A) and SECPT- (B) related increases in state rumination and daily rumination reactivity. Confidence bands indicate standard errors.

Fig. 8. Differences between MDD and HC during control task 1 (CTL1 = reading numbers), control task 2 (CTL2 = performing calculations without social stress) and TSST (arithmetic challenge). Cool colors indicate reduced O2Hb-levels in the MDD group as compared to the HC group; warm colors vice versa. Differences are depicted in Cohen's d. (For interpretation of the references to color in this figure legend, the reader is referred to the Web version of this article.)