Abstract Background Technological advances can be useful to overcome the mainly retrospective research in the field of suicidal behavior. Integrating established theories on suicidal behavior, namely the dynamic system theory and the network theory, the goal of the present study was to examine real life moment-to-moment mood networks between anhedonia, anxiety, depression, hopelessness, irritability, and stress in individuals with a history of suicidal thoughts only, suicidal actions, and no suicidal behavior. Methods A history of suicidal thoughts (wish, ideation) and actions (plan, attempt) was assessed face-to-face using a standardized interview in a random community-based sample of individuals aged 14 to 21 years from Dresden, Germany (N = 1,180, response rate 21.7%). Mood states were examined using smartphone-based Ecological Momentary Assessment (EMA) on four consecutive days eight times a day. The analysis sample included n = 1,072 participants with available EMA data consisting of a suicidal thought group (n = 94), a suicidal action group (n = 76), and a no suicidal behavior group (n = 902). Using vector-autoregression analyses (R package mlVAR), contemporaneous and temporal networks were determined. Results Descriptive results revealed quite similar contemporaneous networks in all groups, except for differences in some edge weights. Temporal networks differed in the overall density pointing towards stronger associations between mood states in the suicidal action group. Here, additional analyses revealed interaction effects by group in the associations between irritability and anhedonia, irritability and stress, anhedonia and hopelessness. Conclusions Future research should consider these patterns in trying to explain why some people act on their suicidal thoughts.

Social anxiety disorder (SAD) is among the most prevalent anxiety disorders, and it has been associated with signs of advanced biological ageing. Despite this, brain age research on anxiety disorders remains limited. This mega-analysis investigated brain ageing in adults with SAD within the ENIGMA-Anxiety Working Group. Structural MRI scans from 576 participants with SAD and 1 355 non-affected healthy controls (HCs) across 26 international samples were included. Brain age was estimated from 77 cortical and subcortical regions using a publicly available ENIGMA brain age model. The brain-predicted age difference (brain-PAD) was calculated as the difference between brain age and chronological age. Group and subgroup differences (comorbidity, medication) were assessed using linear mixed-effect models. In the full sample, there was no group difference in brain-PAD ( β diagnosis (SE)=0.70 (0.37) years, p =0.061). In a subgroup of participants with SAD with comorbid anxiety disorders (n=184 SAD, n=1 355 HCs), a brain-PAD of +2.39 (0.93) years (Cohen's d =0.23, p FDR=0.003) was observed. This brain-PAD became smaller after exclusion of participants with comorbid agoraphobia and specific phobia, suggesting that these disorders may partly drive the advanced brain-PAD. In conclusion, this ENIGMA-Anxiety mega-analysis did not find evidence of advanced brain ageing in the full sample of adult participants with SAD relative to HCs. However, a sub-analysis suggested that SAD with co-occurring phobic disorders, or the phobic disorders themselves, are associated with neurostructural patterns typical of older brains. Future research could utilise transdiagnostic samples with information on age of onset and disorder duration to further clarify this relation.

Specific phobia (SPH) is a prevalent anxiety disorder and may involve advanced biological aging. However, limited brain age research has been conducted in anxiety disorders. This mega-analysis investigated brain aging in SPH participants within the ENIGMA-Anxiety Working Group. 3D brain structural MRI scans from 17 international samples (600 SPH individuals, of whom 504 formally diagnosed and 96 questionnaire-based cases; 1134 controls; age range: 22-75 years) were processed with FreeSurfer. Brain age was estimated from 77 subcortical and cortical regions with a publicly available ENIGMA brain age model. The brain-predicted age difference (brain-PAD) was calculated as brain age minus chronological age. Linear mixed-effects models examined group differences in brain-PAD and moderation by age. No significant group difference in brain-PAD manifested (βdiagnosis [SE] = 0.37 years [0.43], p = 0.39). A negative diagnosis-by-age interaction was identified, which was most pronounced in formally diagnosed SPH (βdiagnosis-by-age = -0.08 [0.03], pFDR = 0.02). This interaction remained significant when excluding participants with anxiety comorbidities, depressive comorbidities, and medication use. Post hoc analyses revealed a group difference for formal SPH diagnosis in younger participants (22-35 years; βdiagnosis = 1.20 [0.60], p < 0.05, mixed-effects d [95% confidence interval] = 0.14 [0.00-0.28]), but not older participants (36-75 years; βdiagnosis = 0.07 [0.65], p = 0.91). Brain aging did not relate to SPH in the full sample. However, a diagnosis-by-age interaction was observed across analyses, and was strongest in formally diagnosed SPH. Post hoc analyses showed subtle advanced brain aging in young adults with formally diagnosed SPH. Taken together, these findings indicate the importance of clinical severity, impairment, and persistence, and may suggest a slightly earlier end to maturational processes or subtle decline of brain structure in SPH.

Prevalence of non-stereotypical Eating Disorders (EDs; e.g., characterized by normal weight, subjective binge eating) is much higher compared with stereotypical EDs (e.g., characterized by under- or overweight, objective binge eating), but treatment rates are much lower. Despite the similar subjective burden, individuals with non-stereotypical symptom presentation are often misperceived and do not receive adequate treatment. Using case vignettes, we investigate not only whether non-stereotypical cases of ED are judged differently by a sample of N = 308 psychotherapists in training than stereotypical cases. Via a quasi-randomized, controlled design, we also investigate whether a short, educational intervention improves clinical judgement. Data analyses via hierarchical modelling confirm that non-stereotypical vignettes are perceived as less severe than stereotypical vignettes. They are also less likely to receive an ED-diagnosis, and treatment is less likely to be seen as indicated. The intervention reduced this difference in judgement, leading to a higher perceived problem severity, a higher likelihood of ED-diagnosis, and a higher rating in treatment urgency for non-stereotypical vignettes. The results draw attention to the problem of misjudgement of non-stereotypical cases of ED. The promising findings regarding the intervention indicate that education of healthcare professionals might contribute to higher likelihood of treatment for individuals with non-stereotypical symptom presentation. Not applicable.

Given robust support for internalizing psychopathology as a broad construct, the field has shifted focus from its specific subcomponents to studying internalizing overall, leaving it unclear whether its components provide additional information. We investigated whether internalizing syndromes have incremental validity beyond each other in their associations with 22 external criteria (e.g., health, functioning) using the National Epidemiological Survey on Alcohol and Related Conditions data, a representative adult sample (Wave 1: N = 43,093). We extracted a five-factor model for five lower-order internalizing syndromes (generalized anxiety, major depression, social anxiety, specific phobia, panic). All were moderately correlated with each other and associated with external criteria. Adjusting for other internalizing syndromes, generalized anxiety, major depression, and panic syndromes demonstrated incremental validity, or unique associations with external criteria. Our findings suggest internalizing syndromes exhibit shared and unique features. Investigating both the internalizing spectrum and its more specific syndromes can offer deeper insights into psychopathology.

First episodes of affective disorders often emerge during adolescence and young adulthood. Alterations in resting-state functional connectivity (RSFC) have been reported in affective disorders, yet findings are heterogeneous and associations of RSFC with subclinical affective symptoms in community samples remain limited. A better understanding of these underlying neurobiological mechanisms may aid in identifying early vulnerability markers of affective disorders. We examined associations between affective symptom severity and both static and dynamic RSFC using resting-state fMRI data from 512 adolescents and young adults (aged 14-23) drawn from an age- and sex-stratified population-based sample. Group independent component analysis was used to derive RSFC measures. Associations with depressive and manic symptom severity were assessed while controlling for age and sex. Dynamic RSFC was analyzed using a sliding-window approach. Static RSFC showed significant effects of age and sex but no associations with affective symptoms. Dynamic RSFC analysis identified four connectivity states. In one state, manic symptom severity and its interaction with depressive symptom severity were associated with connectivity between the postcentral gyrus and the right superior temporal gyrus. Additionally, the dynamic index fraction of time showed interactions of affective symptoms with age and sex. Overall, RSFC measures demonstrated limited sensitivity to subclinical affective symptom variation in community youth, with only a single state-specific association observed. These findings suggest that subtle alterations in somatomotor-default mode network connectivity may reflect early vulnerability-related processes, though replications and further research are required. Key limitations include the use of very brief symptom measures and developmental heterogeneity across the sample.

Higher predicted brain age difference has been associated with several psychiatric disorders. Generalized anxiety disorder (GAD) is associated with markers of accelerated aging. In this study, we determined brain predicted age difference (PAD) in individuals with GAD and healthy controls (HC) as well as group differences in PAD variability using voxel-wise structural MRI. The training dataset included 3,511 controls, and the testing dataset included 1,595 individuals with GAD and 4,552 HC from the ENIGMA-Anxiety GAD Working Group. A convolutional neural network model using four input modalities per subject and a model ensemble approach was used to predict brain age. The PAD was then calculated by subtracting chronological age. Model performance was consistent with other image-based brain age prediction models with similar accuracy across the training set (mean absolute error (MAE) = 2.95 years) and HC in the testing set (MAE = 2.94). We found no evidence of accelerated brain aging in individuals with GAD, though we did find evidence for greater variation in PAD for individuals with GAD (Levene's test: W = 442.98, p < .001) and evidence for greater variability in PAD of those with GAD over 25 years of age. No relationships between PAD and clinical or demographic measures were found. To conclude, using large training and testing samples, the study found no significant association between GAD and PAD, although individuals with GAD had greater heterogeneity in brain-predicted age.

Disruptive behavior and emotional problems – especially anxiety – are common in children and frequently co-occur. However, the role of co-occurring emotional problems in disruptive behavior intervention response is unclear. This study aimed to compare the effectiveness of an indicated prevention program in children with disruptive behavior problems with vs. without co-occurring emotional problems. Children were screened for disruptive behavior and emotional problems during routine health check-ups and – if indicated – were offered a child-centered group prevention program. For children with disruptive behavior the “Baghira training” was administered. Training effectiveness was compared between participating children with vs. without emotional problems regarding disruptive behavior and emotional problems and anxiety in particular. Outcomes were measured before and after the training, and at six months follow-up using linear mixed effect model regression analyses. Overall, regarding disruptive behavior, children with and without co-occurring emotional problems profited equally from the Baghira training and training effectiveness was independent of the pre-training level of anxiety. However, there were few indications for greater disruptive behavior symptom reduction in children with co-occurring emotional problems. Overall, the Baghira training had little to no effect on the examined emotional problems/anxiety measures, except the Strengths and Difficulties Questionnaire emotional problems score strongly decreased in children with co-occurring emotional problems. The effectiveness of the Baghira training is not negatively affected by co-occurring emotional problems/anxiety. However, as emotional problems/anxiety do not simultaneously improve, an additional training targeting these problems for respective children seems necessary.

The relationship between stress, hair cortisol and alcohol consumption has mostly been investigated among clinical and adult study samples, with inconsistent findings. The present study aimed to examine cross-sectional and longitudinal associations between chronic stress, hair cortisol and average past-year alcohol consumption within a population-based sample of adolescents and young adults. At baseline of the epidemiological cohort study, N = 1180 individuals aged 14-21 from Dresden, Germany, were assessed (11/2015-12/2016). A maximum N = 1055 were analysed in cross-sectional analyses and a maximum N = 722 in longitudinal analyses (1-year follow-up). Multivariate linear regression analyses were conducted to reveal cross-sectional associations between perceived chronic stress, hair cortisol concentration and average past-year alcohol consumption in males and females. Longitudinally, weighted linear regression models examined relationships between (a) perceived chronic stress at baseline and altered hair cortisol concentration over 1 year, (b) perceived chronic stress/hair cortisol concentration at baseline and altered average alcohol consumption over 1 year and (c) average past-year alcohol consumption at baseline and altered stress/hair cortisol concentration over 1 year. Cross-sectionally, no significant relationships were found between stress, hair cortisol and average past-year alcohol consumption at baseline. In females, higher baseline perceived chronic stress was associated with an increase in hair cortisol concentration over 1 year, whereas no relationship was found in the cross-sectional analysis between baseline perceived chronic stress and baseline past-year average alcohol consumption. When using hair cortisol as a biomarker for stress perception, the focus of future research should be on potential time lags between perceived chronic stress and hair cortisol increase.

Background:Specific phobia (SP) is a prevalent mental disorder for which exposure-based treatments are the most effective. Little is known about the intrinsic functional connectivity of SP and its modification by treatment. While previous studies were limited to a priori-defined brain regions, we used connectome-wide analyses to capture the full extent of altered functional connectivity. Methods:We used functional magnetic resonance imaging in combination with hypothesis-free, data-driven functional connectivity multivariate pattern analysis (fc-MVPA) to identify differences between 72 individuals with SP and a nonphobic control group (CG) (n = 82). The SP group then received a one-session exposure treatment and was scanned again 9 weeks later on average. Results:fc-MVPA identified the largest differences between the SP group and CG in sensorimotor regions, with lower connectivity to temporal nodes of the default network and anticorrelations with the frontoparietal network in the SP group compared with the CG. Stronger connectivity in the pretreatment compared with the posttreatment condition was evident in visual regions, while anticorrelations with the frontoparietal network were reduced. Post hoc comparisons showed that the connectivity strengths of the SP group after treatment between almost all identified nodes of both contrasts (SP vs. CG and pre vs. post) were comparable to those of the CG at baseline. Conclusions:Given the known functions of the identified networks, it is possible that the changes in connectivity measured after treatment indicate improved action control, enabled by more accurate prediction of the environment and stronger coupling of perceptual and action regions with higher-order control regions.

BACKGROUND AND AIMS:Emotional and behavioural problems occur frequently in childhood and are usually associated with burdens on children, families, and society. Preventive interventions could reduce these burdens, but are rarely used despite their availability and effectiveness. The aim was to identify general, individual, structural, and family-related barriers/facilitators to potential and actual participation in prevention programs. METHODS:As part of a prospective implementation study, n = 3,231 project folders were handed out to parents in 28 paediatric practices in Dresden and surrounding area during routine health check-ups (U9-U11) for children aged 5 to 10 years. In addition to screening for mental health problems, a questionnaire was used to identify potential barriers/facilitators to participation in prevention programs. Of n = 2,844 families agreeing to participate in the study n = 2,122 (74.6 %) completed the questionnaire at least partially. Regression analyses were used to test associations between potential barriers/facilitators and actual participation in (a) a pre-intervention interview (PII; in order to check indications with the program provider) or (b) the prevention program among children with a prevention recommendation. RESULTS:Of the participating families, 1.8 % reported that they had already participated in a prevention program to improve mental health or had received a recommendation for it before. 59.5 % of the families expressed their general interest in such programs, and 95.7 % would participate if their paediatrician recommended it. At the structural level, a lack of knowledge about mental health prevention programs was identified as a barrier to potential participation; as only 9.2 % of the families were aware of such programs before participating in the study. 65.8 % of all the families considered full reimbursement of the participation fees after paying in advance a prerequisite for their potential program participation, and 56.7 % wanted to receive a voucher from their health insurance fund entitling them to participate without prepayment. At the individual level, the parents' attitude towards the usefulness of prevention programs predicted the actual utilisation of the PII after the paediatrician's recommendation. At the structural level, the acceptance of longer travel times (up to 60 minutes) as well as the assumption/reimbursement of the entire course fees were relevant predictors. Furthermore, male sex (of the children) and higher screening scores were also important predictors at the family-related level. After the PII, the only factor associated with actual participation in prevention programs was efficient public transport accessibility. DISCUSSION:In order to increase participation in prevention programs, funding to cover participation fees should be secured through health insurance funds. In addition, advertising and educational measures in the public as well as by paediatricians in the context of screening could raise the awareness of and improve attitudes towards useful programs. Implementing the programs in children's environments could reduce structural barriers and create equal opportunities for participation.

Introduction:Specific phobia (SPH) is a prevalent anxiety disorder and may involve advanced biological aging. However, brain age research in psychiatry has primarily examined mood and psychotic disorders. This mega-analysis investigated brain aging in SPH participants within the ENIGMA-Anxiety Working Group. Methods:3D brain structural MRI scans from 17 international samples (600 SPH individuals, of whom 504 formally diagnosed and 96 questionnaire-based cases; 1,134 controls; age range: 22-75 years) were processed with FreeSurfer. Brain age was estimated from 77 subcortical and cortical regions with a publicly available ENIGMA brain age model. The brain-predicted age difference (brain-PAD) was calculated as brain age minus chronological age. Linear mixed-effect models examined group differences in brain-PAD and moderation by age. Results:No significant group difference in brain-PAD manifested (β diagnosis (SE)=0.37 years (0.43), p=0.39). A negative diagnosis-by-age interaction was identified, which was most pronounced in formally diagnosed SPH (β diagnosis-by-age=-0.08 (0.03), pFDR=0.02). This interaction remained significant when excluding participants with anxiety comorbidities, depressive comorbidities, and medication use. Post-hoc analyses revealed a group difference for formal SPH diagnosis in younger participants (22-35 years; β diagnosis=1.20 (0.60), p<0.05, mixed-effects d (95% confidence interval)=0.14 (0.00-0.28)), but not older participants (36-75 years; β diagnosis=0.07 (0.65), p=0.91). Conclusions:Brain aging did not relate to SPH in the full sample. However, a diagnosis-by-age interaction was observed across analyses, and was strongest in formally diagnosed SPH. Post-hoc analyses showed a subtle advanced brain aging in young adults with formally diagnosed SPH. Taken together, these findings indicate the importance of clinical severity, impairment and persistence, and may suggest a slightly earlier end to maturational processes or subtle decline of brain structure in SPH.

Specific phobia (SP) is a prevalent mental disorder. Exposure-based treatments are the most effective therapy. Surprisingly, little is known about the intrinsic functional connectivity of SP and its modification by treatment, possibly due to a strong focus on a presumed fear network. Hypothesis-driven a priori selection of brain regions does not allow the full extent of potential changes in SP and the modulating effects of therapy to be captured. Therefore, we use functional magnetic resonance imaging (fMRI) in combination with hypothesis-free, data-driven functional connectivity multivariate pattern analysis (fc-MVPA), which takes into account the entire functional connectome, to identify differences between N=72 individuals with SP and a non-phobic control group (CG, N=82). The SP group then received a one-session exposure treatment and was scanned again after 16 weeks.Fc-MVPA showed the largest differences between SP and CG in somatomotor regions with higher connectivity to temporal nodes of the default network and anti-correlations to the frontoparietal network. Stronger connectivity values in the pre- compared to the post-treatment condition was evident in visual regions. while anti-correlations to the frontoparietal network were reduced. Post-hoc comparisons showed that the connectivity patterns of the SP after treatment between almost all identified nodes of both contrasts ('SP vs. CG' and 'pre vs. post') were comparable to those of the control group. Given the known functions of the identified networks, the results suggest that exposure treatment may improve the control of perceptual and action regions, leading to better environmental prediction of mentally constructed scenes and improved action control.

BACKGROUND:Decision-making processes may play a pivotal role in the etiology and maintenance of specific phobia. However, empirical evidence is limited. This study examined whether decision-making is only impaired in presence of fear-related stimuli or whether general impairments exist but are more pronounced in the presence of fear-related stimuli. Further, we examine which components of the decision-making process might be impaired. METHODS:We examined a spider phobia group (SP, n = 109) relative to matched healthy controls (HC, n = 81) using a virtual decision game. To tap the approach-avoidance-conflict, either a fear-related version (using spiders) or a non-phobic version of the task was used in a between-subjects design to measure how the presence of fear-related or non-phobic stimuli was associated with optimal decision-making (collecting rewards). Based on drift diffusion modelling, underlying decision-making processes such as processing ability and cautiousness were investigated. RESULTS:No clear evidence for general impairments of decision-making for SP participants relative to HC in the absence of fear-related stimuli was found, but a strong phobia-specific impairment when fear-related stimuli were present. These avoidant decisions were associated with a reduced ability to process the optimal choice option and increased cautiousness in the SP group. CONCLUSIONS:Decision-making processes in specific phobia are specifically impaired in the presence of fear-related stimuli, which might contribute to maladaptive, costly avoidance behavior.

BACKGROUND:Externalizing and internalizing disorders are common in youth but are often studied separately, preventing researchers from identifying shared (i.e., transdiagnostic) alterations in brain structure. Using data from the ENIGMA (Enhancing Neuro Imaging Genetics through Meta Analysis) Consortium, we conducted a mega-analysis to identify shared and distinct cortical and subcortical brain alterations across internalizing (anxiety disorders and depression) and externalizing (attention-deficit/hyperactivity disorder [ADHD] and conduct disorder [CD]) disorders in youth. METHODS:3D T1-weighted magnetic resonance imaging data from youths (age range 4-21 years) with anxiety disorders (n = 1044), depression (n = 504), ADHD (n = 1317), and CD (n = 1172) along with healthy control participants (n = 4743) were analyzed. We assessed group differences in regional cortical thickness, surface area (SA), and subcortical volume using linear models, adjusted for site, age, and sex, as well as total intracranial volume in the SA and subcortical volume models. RESULTS:We observed transdiagnostic associations, with both internalizing and externalizing disorders characterized by lower SA in the insula, entorhinal cortex, and middle temporal gyrus and lower amygdala volume (Cohen's ds = -0.07 to -0.24) as well as total SA and intracranial volume (ds = -0.11 to -0.25). Externalizing-specific reductions in SA were observed in frontoparietal regions (ds = -0.08 to -0.13), but no internalizing-specific associations were identified. Disorder-specific alterations were identified for ADHD, CD, and anxiety disorders but not depression. CONCLUSIONS:Both common and disorder-specific alterations were identified, with regions involved in salience attribution and emotion processing implicated across internalizing and externalizing disorders. These novel findings can guide future research targeting common biological processes across youth psychiatric disorders as well as features unique to individual disorders.

Disruptive behavior and emotional problems are common in children and often reduce quality of life. This study aimed to screen for these problems and to examine the effectiveness of child-based indicated prevention. N = 3231 children`s disruptive behavior and emotional problems were screened using the Strengths and Difficulties Questionnaire (SDQ) during routine pediatric health check-ups for usually 5- to 10-year old’s. We examined the prevalences of disruptive behavior and emotional problems (n = 2825) and its association with quality of life (KINDL; n = 1104). If indicated, children were recommended to participate in the prevention program “Baghira training” (nine 90 min group sessions and one parents’ evening) or “Tiger training” (two one-on-one and nine group sessions of 60 min each). To evaluate the training effectiveness of the two indicated prevention programs, SDQ and KINDL scores were followed-up for 6 and 12 months post screening and compared between the Training group (SDQ n = 337; KINDL n = 334; additionally divided into Baghira and Tiger), children not participating despite indication (NoTraining; SDQ n = 595; KINDL n = 146; additionally divided into NoBaghira and NoTiger), healthy children (SDQ n = 1928; KINDL n = 907), and children with clinical symptom levels (SDQ n = 85; KINDL n = 54) using mixed effect models. 37.0

Subclinical disruptive behavior problems often occur during childhood and are a risk factor for developing a mental disorder later in life. To prevent a manifestation of dysfunctional disruptive behavior, early intervention is critical. This study aimed to examine the effectiveness of an indicated prevention program in children with disruptive behavior problems. Screening for disruptive behavior problems was conducted using the Strength and Difficulties Questionnaire during routine pediatric health check-ups. Depending on their risk status (normal vs. borderline vs. abnormal), children received a recommendation for no intervention, an indicated prevention program (i.a. “Baghira”) or further diagnostics. Questionnaires such as the Child Behavior Checklist and the Parent Rating Scale for Conduct Disorder (DISYPS Competence scale) were administered at three time points (T0: pre-intervention, T1: 6 months after screening/ post-intervention, T2: 6 months after T1). Children who participated in “Baghira” (BA n = 171), a cognitive-behavioral group program for children with disruptive behaviors, were compared to children screened as normal (NOR n = 881) or received a recommendation for “Baghira” but refused participation (NO BA n = 46). Disruptive behavior problems decreased (BA: β = − 3.61, p <.001) and prosocial behavior increased (BA: β = 1.67, p <.001) in the BA compared to the NOR group from T0 to T1. These effects were maintained at T2 follow-up (BA: β = − 1.60; p =.035; β = 1.12; p =.019). However, the NO BA group also improved in prosocial behavior and from T0 to T1. Although an improvement in disruptive behavior symptoms as well as an increase in prosocial behavior were observed, controlled studies using matched or stratified designs are needed to replicate the effectiveness of “Baghira” in a prevention context, apart from the Covid-19 pandemic, to improve children’s mental health.

BackgroundThis study examined the cognitive, behavioral, and affective mechanisms underlying the efficacy of Applied Relaxation (AR) in reducing psychopathological symptoms. AR is a cognitive-behavioral technique that allows for rapid relaxation at the first sign of stress or tension in daily life.MethodsA randomized controlled trial was conducted in 277 adults (18-55 years) with elevated symptoms of depression, anxiety, or stress but without a 12-month DSM-5 mental disorder at study entry. Participants were randomized to an intervention group receiving AR training (10 weeks, n=139) and an assessment-only control group (n=138). Mental health outcomes (depressive, anxiety, and stress symptoms) and potential cognitive (self-efficacy, perceived control), behavioral (coping behaviors) and affective (positive and negative affect) mediators of the intervention efficacy were assessed at baseline and post-assessment in both groups.ResultsStructural equation models indicated that baseline to post reductions in psychopathological symptoms due to AR partially passed through less avoidance-oriented and less other dysfunctional coping (proportion of total effect mediated; ratio of indirect to total effect: resignation: 55.0%, rumination: 27.9%, escape: 27.4%, aggression: 21.3%), less negative affect (46.3%), more positive affect (41.8%), lower external control beliefs (14.5%), and higher self-efficacy (13.3%).ConclusionsOur results suggest that improvements in cognitive, behavioral, and affective mediator variables partially explain the intervention efficacy of AR in improving mental health.Trial registration and data statementThe study protocol has been pre-registered on ClinicalTrials.gov (NCT03311529). The study protocol, minimum dataset, and analysis codes are available at OpARA - Open Access Repository and Archive. Supplementary materials (e.g., the course manual and additional training materials) are available on request from the last author (katja.beesdo-baum@tu-dresden.de).