Background: Exercise efficaciously reduces disorder-specific symptoms of psychiatric disorders. The current study aimed to examine the efficacy of a group exercise intervention on global symptom severity and disorder-specific symptoms among a mixed outpatient sample. Methods: Groups of inactive outpatients, waiting for psychotherapy, with depressive disorders, anxiety disorders, insomnia, and attention-deficit/hyperactivity disorders were randomized to a manualized 12-week exercise intervention, combining moderate to vigorous aerobic exercise with techniques for sustainable exercise behaviour change (n = 38, female = 71.1% (n = 27), M_age = 36.66), or a passive control group (n = 36, female = 75.0% (n = 27), M_age = 34.33). Primary outcomes were global symptom severity and disorder-specific symptoms, measured with the Symptom Checklist-90-Revised and Pittsburgh Sleep Quality Index pre- and post-treatment. Secondary outcome was the self-reported amount of exercise (Physical Activity, Exercise, and Sport Questionnaire), measured pre-treatment, intermediate-, and post-treatment. Intention-to-treat analyses were conducted using linear mixed models. Linear regressions were conducted to examine the effect of the change of exercise behaviour on the change of symptoms. Results: The intervention significantly improved global symptom severity (d = 0.77, p = .007), depression (d = 0.68, p = .015), anxiety (d = 0.87, p = .002), sleep quality (d = 0.88, p = .001), and increased the amount of exercise (d = 0.82, p < .001), compared to the control group. Post-treatment differences between groups were significant for depression (d = 0.63, p = .031), sleep quality (d = 0.61, p = .035) and the amount of exercise (d = 1.45, p < .001). Across both groups, the reduction of global symptom severity was significantly predicted by an increase of exercise (b = .35, p = .012). Conclusions: The exercise intervention showed transdiagnostic efficacy among a heterogeneous clinical sample in a realistic outpatient setting and led to sustained exercise behaviour change. Exercise may serve as an efficacious and feasible transdiagnostic treatment option improving the existing treatment gap within outpatient mental health care settings. Trial registration: The study was registered on ClinicalTrials.gov (ID: NCT03542396, 25/04/2018).

Background: Mental disorders are prevalent and cause considerable burden of disease. Exercise has been shown to be efficacious to treat major depressive disorders, insomnia, panic disorder with and without agoraphobia and post traumatic stress disorder (PTSD). Methods: This pragmatic, two arm, multi-site randomised controlled trial will evaluate the efficacy and cost-effectiveness of the manualized, group-based six-months exercise intervention “ImPuls”, among physically inactive patients with major depressive disorders, insomnia, panic disorder, agoraphobia and PTSD within a naturalistic outpatient context in Germany. A minimum of 375 eligible outpatients from 10 different study sites will be block-randomized to either ImPuls in addition to treatment as usual (TAU) or TAU only. ImPuls will be conducted by trained exercise therapists and delivered in groups of six patients. The program will combine (a) moderate to vigorous aerobic exercise carried out two-three times a week for at least 30 min with (b) behavior change techniques for sustained exercise behavior change. All outcomes will be assessed pre-treatment, post-treatment (six months after randomization) and at follow-up (12 months after randomization). Primary outcome will be self-reported global symptom severity assessed with the Brief Symptom Inventory (BSI-18). Secondary outcomes will be accelerometry-based moderate to vigorous physical activity, self-reported exercise, disorder-specific symptoms, quality-adjusted life years (QALY) and healthcare costs. Intention-to-treat analyses will be conducted using mixed models. Cost-effectiveness and cost-utility analysis will be conducted using incremental cost-effectiveness and cost-utility ratios. Discussion: Despite its promising therapeutic effects, exercise programs are currently not provided within the outpatient mental health care system in Germany. This trial will inform service providers and policy makers about the efficacy and cost-effectiveness of the group-based exercise intervention ImPuls within a naturalistic outpatient health care setting. Group-based exercise interventions might provide an option to close the treatment gap within outpatient mental health care settings. Trial registration: The study was registered in the German Clinical Trials Register (ID: DRKS00024152, 05/02/2021).

This study investigated emotion regulation (ER) difficulties and repetitive negative thinking (RNT) in individuals with depression, anxiety disorders, or both, compared to nonclinical controls. We aimed to determine which aspects of ER difficulties and RNT are transdiagnostic or specific to one of the disorders, and whether the presence of comorbidities is associated with greater ER difficulties and higher levels of RNT. A total of N = 731 participants, including n = 354 individuals with depression, anxiety disorders, or both (mixed group), and n = 377 nonclinical controls, completed the Difficulties in Emotion Regulation Scale (DERS) and the Perseverative Thinking Questionnaire (PTQ). Parametric and nonparametric analyses were conducted to assess group differences and comorbidity effects. The depression and anxiety disorders groups exhibited significantly greater ER difficulties and higher levels of RNT than nonclinical controls. The mixed group showed more pronounced difficulties in certain aspects of ER (nonacceptance of emotional responses, difficulties engaging in goal‐directed behavior, impulse control difficulties, and limited access to ER strategies) and higher levels of RNT compared to the single‐diagnosis groups. No significant differences were found in emotional awareness and clarity across clinical groups. Evidence regarding the relationship between the number of comorbid diagnoses and the severity of the difficulties was less clear. This suggests that specific disorders may have a more significant impact than comorbidity alone. Our findings highlight the transdiagnostic role of ER difficulties and RNT in depression and anxiety disorders and suggest that they may be a promising target for transdiagnostic interventions. Future research should further explore the nuanced ways in which ER difficulties and RNT vary across different mental disorders.