Anxiety onset in adolescents: a machine-learning prediction.

Recent longitudinal studies in youth have reported MRI correlates of prospective anxiety symptoms during adolescence, a vulnerable period for the onset of anxiety disorders. However, their predictive value has not been established. Individual prediction through machine-learning algorithms might help bridge the gap to clinical relevance. A voting classifier with Random Forest, Support Vector Machine and Logistic Regression algorithms was used to evaluate the predictive pertinence of gray matter volumes of interest and psychometric scores in the detection of prospective clinical anxiety. Participants with clinical anxiety at age 18-23 (N = 156) were investigated at age 14 along with healthy controls (N = 424). Shapley values were extracted for in-depth interpretation of feature importance. Prospective prediction of pooled anxiety disorders relied mostly on psychometric features and achieved moderate performance (area under the receiver operating curve = 0.68), while generalized anxiety disorder (GAD) prediction achieved similar performance. MRI regional volumes did not improve the prediction performance of prospective pooled anxiety disorders with respect to psychometric features alone, but they improved the prediction performance of GAD, with the caudate and pallidum volumes being among the most contributing features. To conclude, in non-anxious 14 year old adolescents, future clinical anxiety onset 4-8 years later could be individually predicted. Psychometric features such as neuroticism, hopelessness and emotional symptoms were the main contributors to pooled anxiety disorders prediction. Neuroanatomical data, such as caudate and pallidum volume, proved valuable for GAD and should be included in prospective clinical anxiety prediction in adolescents.

Cognitive and brain development is independently influenced by socioeconomic status and polygenic scores for educational attainment.

Genetic factors and socioeconomic status (SES) inequalities play a large role in educational attainment, and both have been associated with variations in brain structure and cognition. However, genetics and SES are correlated, and no prior study has assessed their neural associations independently. Here we used a polygenic score for educational attainment (EduYears-PGS), as well as SES, in a longitudinal study of 551 adolescents to tease apart genetic and environmental associations with brain development and cognition. Subjects received a structural MRI scan at ages 14 and 19. At both time points, they performed three working memory (WM) tasks. SES and EduYears-PGS were correlated (r = 0.27) and had both common and independent associations with brain structure and cognition. Specifically, lower SES was related to less total cortical surface area and lower WM. EduYears-PGS was also related to total cortical surface area, but in addition had a regional association with surface area in the right parietal lobe, a region related to nonverbal cognitive functions, including mathematics, spatial cognition, and WM. SES, but not EduYears-PGS, was related to a change in total cortical surface area from age 14 to 19. This study demonstrates a regional association of EduYears-PGS and the independent prediction of SES with cognitive function and brain development. It suggests that the SES inequalities, in particular parental education, are related to global aspects of cortical development, and exert a persistent influence on brain development during adolescence.

Linked patterns of biological and environmental covariation with brain structure in adolescence: a population-based longitudinal study.

Adolescence is a period of major brain reorganization shaped by biologically timed and by environmental factors. We sought to discover linked patterns of covariation between brain structural development and a wide array of these factors by leveraging data from the IMAGEN study, a longitudinal population-based cohort of adolescents. Brain structural measures and a comprehensive array of non-imaging features (relating to demographic, anthropometric, and psychosocial characteristics) were available on 1476 IMAGEN participants aged 14 years and from a subsample reassessed at age 19 years (n = 714). We applied sparse canonical correlation analyses (sCCA) to the cross-sectional and longitudinal data to extract modes with maximum covariation between neuroimaging and non-imaging measures. Separate sCCAs for cortical thickness, cortical surface area and subcortical volumes confirmed that each imaging phenotype was correlated with non-imaging features (sCCA r range: 0.30-0.65, all PFDR < 0.001). Total intracranial volume and global measures of cortical thickness and surface area had the highest canonical cross-loadings (|ρ| = 0.31-0.61). Age, physical growth and sex had the highest association with adolescent brain structure (|ρ| = 0.24-0.62); at baseline, further significant positive associations were noted for cognitive measures while negative associations were observed at both time points for prenatal parental smoking, life events, and negative affect and substance use in youth (|ρ| = 0.10-0.23). Sex, physical growth and age are the dominant influences on adolescent brain development. We highlight the persistent negative influences of prenatal parental smoking and youth substance use as they are modifiable and of relevance for public health initiatives.

Randomized controlled trial of cognitive remediation therapy in adolescent inpatients with anorexia nervosa: Neuropsychological outcomes.

OBJECTIVE: Neuropsychological dysfunction exists in anorexia nervosa (AN). Cognitive Remediation Therapy (CRT), mainly evaluated in adults with AN, targets these impairments. METHODS: Adolescent inpatients (age = 11-17 years) with AN were randomized to 5 weeks of either 10 sessions of individually delivered CRT or non-specific cognitive-training (NSCT). Co-primary outcomes included cognitive domain 'flexibility' [composite score of Wisconsin Card Sorting Test (WSCT) and Trail Making Test (TMT-4)] and 'central coherence' [composite score of Central Coherence Index (CCI) and Group Embedded Figures Test (GEFT)] at end of treatment (FU1). Secondary outcomes included individual test scores and self-reported everyday-life flexibility at FU1 and at 6-months post-treatment (FU2). Independent sample t-tests, Pearson chi-square-tests and mixed models for repeated measures (MMRM) analyses were conducted. RESULTS: In 56 females (age = 15.1 ± 1.5 years), CRT was not superior to NSCT at FU1 regarding 'flexibility' (p = 0.768) or 'central coherence' (p = 0.354), nor at FU2 (p = 0.507; p = 0.624) (effect sizes = 0.02-0.26). Both groups improved over time in central coherence (CCI p = 0.001; GEFT p < 0.001), self-reported flexibility (p = 0.002) and WCST (p = 0.18), but not TMT-4 (p = 0.286). NSCT was superior to CRT regarding self-reported planning/organisation ability at FU1 (p < 0.001) and FU2 (p = 0.003). CONCLUSIONS: CRT was not superior to NSCT in adolescent inpatients with AN. More randomized controlled studies are needed.

Distinct brain structure and behavior related to ADHD and conduct disorder traits.

Attention-Deficit/Hyperactivity Disorder (ADHD) and conduct disorder (CD) exemplify top-down dysregulation conditions that show a large comorbidity and shared genetics. At the same time, they entail two different types of symptomology involving mainly non-emotional or emotional dysregulation. Few studies have tried to separate the specific biology underlying these two dimensions. It has also been suggested that both types of conditions consist of extreme cases in the general population where the symptoms are widely distributed. Here we test whether brain structure is specifically associated to ADHD or CD symptoms in a general population of adolescents (n = 1093) being part of the IMAGEN project. Both ADHD symptoms and CD symptoms were related to similar and overlapping MRI findings of a smaller structure in prefrontal and anterior cingulate cortex. However, our regions of interest (ROI) approach indicated that gray matter volume (GMV) and surface area (SA) in dorsolateral/dorsomedial prefrontal cortex and caudal anterior cingulate cortex were negatively associated to ADHD symptoms when controlling for CD symptoms while rostral anterior cingulate cortex GMV was negatively associated to CD symptoms when controlling for ADHD symptoms. The structural findings were mirrored in performance of neuropsychological tests dependent on prefrontal and anterior cingulate regions, showing that while performance on the Stop Signal test was specifically related to the ADHD trait, delayed discounting and working memory were related to both ADHD and CD traits. These results point towards a partially domain specific and dimensional capacity in different top-down regulatory systems associated with ADHD and CD symptoms.

Sex effects on structural maturation of the limbic system and outcomes on emotional regulation during adolescence.

Though adolescence is a time of emerging sex differences in emotions, sex-related differences in the anatomy of the maturing brain has been under-explored over this period. The aim of this study was to investigate whether puberty and sexual differentiation in brain maturation could explain emotional differences between girls and boys during adolescence. We adapted a dedicated longitudinal pipeline to process structural and diffusion images from 335 typically developing adolescents between 14 and 16 years. We used voxel-based and Regions of Interest approaches to explore sex and puberty effects on brain and behavioral changes during adolescence. Sexual differences in brain maturation were characterized by amygdala and hippocampal volume increase in boys and decrease in girls. These changes were mediating the sexual differences in positive emotional regulation as illustrated by positive attributes increase in boys and decrease in girls. Moreover, the differential maturation rates between the limbic system and the prefrontal cortex highlighted the delayed maturation in boys compared to girls. This is the first study to show the sex effects on the differential cortico/subcortical maturation rates and the interaction between sex and puberty in the limbic system maturation related to positive attributes, reported as being protective from emotional disorders.

Heavy drinking in adolescents is associated with change in brainstem microstructure and reward sensitivity.

Heavy drinker adolescents: altered brainstem microstructure.

The cortical-cerebellar circuit is vulnerable to heavy drinking (HD) in adults. We hypothesized early microstructural modifications of the pons/midbrain region, containing core structures of the reward system, in HD adolescents. Thirty-two otherwise symptom-free HDs at age 14 (HD14) and 24 abstainers becoming HDs at age 16 (HD16) were identified in the community with the Alcohol Use Disorders Identification Test (AUDIT) and compared with abstainers. The monetary incentive delay (MID) task assessed reward-sensitive performance. Voxelwise statistics of diffusion tensor imaging (DTI) values in the thalamo-ponto-mesencephalic region were obtained using tract-based spatial statistics. Projections between the ventral tegmental area (VTA) and the nucleus accumbens (NAcc) were identified by probabilistic tractography. Lower fraction of anisotropy and higher radial diffusivity (RD) values were detected in the upper dorsal pons of HD14 adolescents, and a trend for higher RD in HD16, compared with abstainers. When expecting reward, HD14 had higher MID task success scores than abstainers, and success scores were higher with a lower number of tracts in all adolescents. In symptom-free community adolescents, a region of lower white matter (WM) integrity in the pons at age 14 was associated with current HD and predicted HD at age 16. HD was related to reward sensitivity.

A multicentre randomized controlled trial on trans-generational attention deficit/hyperactivity disorder (ADHD) in mothers and children (AIMAC): an exploratory analysis of predictors and moderators of treatment outcome.

OBJECTIVE: We examined predictors and moderators of treatment outcome in mothers and children diagnosed with ADHD in a large multicentre RCT. METHOD: In total, 144 mother-child dyads with ADHD were randomly assigned to either a maternal ADHD treatment (group psychotherapy and open methylphenidate medication, TG) or to a control treatment (individual counselling without psycho- or pharmacotherapy, CG). After maternal ADHD treatment, parent-child training (PCT) for all mother-child dyads was added. The final analysis set was based on 123 dyads with completed primary outcome assessments (TG: n = 67, CG: n = 56). The primary outcome was the change in each child's externalizing symptoms. Multiple linear regression analyses were performed. RESULTS: The severity of the child's externalizing problem behaviour in the family at baseline predicted more externalizing symptoms in the child after PCT, independent of maternal treatment. When mothers had a comorbid depression, TG children showed more externalizing symptoms after PCT than CG children of depressive mothers. No differences between the treatment arms were seen in the mothers without comorbid depression. CONCLUSIONS: Severely impaired mothers with ADHD and depressive disorder are likely to need additional disorder-specific treatment for their comorbid psychiatric disorders to effectively transfer the contents of the PCT to the home situation (CCTISRCTN73911400).

Differences in set-shifting and central coherence across anorexia nervosa subtypes in children and adolescents.

OBJECTIVE: Regarding executive functioning in anorexia nervosa (AN), little is known about differences between the restricting (AN-R) and binge eating/purging (AN-BP) subtypes. Especially for adolescents, there is sparse data. Hence, the current aim is to investigate differences in set-shifting, central coherence, and self-reported executive functioning across adolescent AN subtypes. METHODS: Ninety AN-R, 21 AN-BP, and 63 controls completed an extensive assessment battery including neuropsychological tests for executive functioning and the self-report questionnaire Behavior Rating Inventory of Executive Functioning. RESULTS: Patients with AN-R and AN-BP did not differ on neuropsychological measures, and both performed similarly to controls. Behavior Rating Inventory of Executive Functioning scores fell within the normal range with AN subtypes showing mostly comparable ratings. AN-BP patients scored higher on 2 composite indices and the "shift" subscale compared with AN-R. CONCLUSIONS: The results suggest similar cognitive functioning in adolescent AN subtypes as well as healthy controls. However, more research is needed to draw more general conclusions.

Clinical characteristics of early onset anorexia nervosa.

The aim of the current paper is to evaluate clinical characteristics of 30 children with early onset anorexia nervosa (EO-AN; age = 12.2 ± 1.6 years) compared with 30 patients with adolescent onset AN (AO-AN; age = 15.9 ± 0.7 years) and 60 age-matched healthy controls. Statistical analyses included one-way analyses of variance with three planned comparisons and chi-square tests. Compared with AO-AN, EO-AN patients displayed more restrictive eating behaviour (p = 0.038), received more tube-feeding (p = 0.024), and had less problems with self-esteem (p < 0.001) and perfectionism (p = 0.001). EO-AN patients have similar eating disorder pathology (p = 0.183), body-image distortion (p = 0.060), and number of hospitalizations (p = 0.358) as AO-AN. Only a third of EO-AN patients suffer from low self-esteem. Overall, core AN pathology seems similar in EO-AN and AO-AN. However, EO-AN patients show differences in their pathological eating behaviour and the need for tube-feeding.

Follow-up Assessment of Cognitive Remediation Therapy in Adolescent Anorexia Nervosa: A Pilot Study.

OBJECTIVE: Cognitive remediation therapy (CRT) is a specialized treatment approach targeting cognitive weaknesses in anorexia nervosa (AN). Regarding follow-up effects of CRT, there are only few studies available; for adolescents, there are no data. METHODS: Forty-eight adolescents with AN were assigned to receive either CRT and treatment as usual (TAU) or TAU alone. Assessments were performed at baseline (n = 48) and compared with assessments at a 6-month follow-up (n = 33). Outcome measures were set-shifting, central coherence, eating disorder and general psychopathology. RESULTS: The completion rate was higher in CRT compared with TAU. There were no significant differences in neuropsychological and clinical variables. Changes in body mass index percentile showed a trend towards significance for CRT. Dropout analyses revealed no significant predictors. CONCLUSIONS: Results provide a first insight into follow-up-assessments of CRT in adolescent AN. More randomized controlled studies are needed to clarify the long-term effects of CRT. Copyright © 2017 John Wiley & Sons, Ltd and Eating Disorders Association.

Cognitive Flexibility in Juvenile Anorexia Nervosain Relation to Comorbid Symptoms of Depression, Obsessive Compulsive Symptoms and Duration of Illness.

OBJECTIVE: Whereas the evidence in adolescents is inconsistent, anorexia nervosa (AN) in adults is characterized by weak cognitive flexibility. This study investigates cognitive flexibility in adolescents with AN and its potential associations with symptoms of depression, obsessive compulsive disorder (OCD), and duration of illness. METHODS: 69 patients and 63 age-matched healthy controls (HC) from 9 till 19 years of age were assessed using the Trail-Making Test (TMT) and self-report questionnaires. RESULTS: In hierarchical regression analyses, set-shifting ability did not differ between AN and HC, whereas AN patients reported significantly higher rates of depression symptoms and OCD symptoms. Age significantly predicted set-shifting in the total sample. Only among AN patients aged 14 years and older did set-shifting decline with increasing age. DISCUSSION: The presence of AN with depression or OCD symptoms or the duration of illness do not influence cognitive flexibility in children and adolescents. Early interventions may be helpful to prevent a decline in cognitive flexibility in adolescent AN with increasing age.

Cognitive performance in children with acute early-onset anorexia nervosa.

When anorexia nervosa (AN) occurs in children below the age of 14 years, it is referred to as early-onset AN (EO-AN). Over the last years, there has been an increased focus on the role of cognitive functioning in the development and maintenance of AN. Adults with AN show inefficiencies in cognitive functions such as flexibility and central coherence. Systematic neuropsychological examinations of patients with EO-AN are missing. Thirty children with EO-AN and 30 adolescents with AN, as well as 60 healthy controls (HC) underwent an extensive neuropsychological examination. ANOVAs with post hoc tests and explorative regression analyses were conducted. Patients with EO-AN (mean age = 2.17 ± 1.57 years) showed no significant differences in flexibility, inhibition, planning, central coherence, visuospatial short- and long-term memory or recognition in comparison to HC (mean age = 11.62 ± 1.29 years). Performance of adolescents with AN (mean age = 15.93 ± 0.70 years) was not significantly different compared to HC (mean age = 16.20 ± 1.26 years). Explorative regression analyses revealed a significant interaction of age and group for flexibility (adjusted R 2  = 0.30, F = 17.85, p = 0.013, η p2  = 0.32). Contrary to expectations, the current study could not confirm the presence of inefficient cognitive processing in children with EO-AN compared to HC. Nonetheless, the expected age-related improvement of flexibility might be disrupted in children and adolescents with AN. Longitudinal neuropsychological examinations are necessary to provide more information about the role of cognitive functioning in the development and maintenance of AN.

Neuropsychological and Behavioural Short-Term Effects of Cognitive Remediation Therapy in Adolescent Anorexia Nervosa: A Pilot Study.

OBJECTIVE: Cognitive remediation therapy (CRT) aims to strengthen weak cognitive flexibility and central coherence in adult and adolescent anorexia nervosa (AN). Currently, there are no studies in adolescents with AN that control for learning effects because of re-testing while evaluating CRT. METHOD: Twenty in- and outpatients with AN aged 12 to 18 years received CRT. Assessment took place directly before and after the intervention. Performance was compared to 20 age-, gender-, IQ-, and test-retest interval matched healthy controls, which did not receive CRT. RESULTS: AN patients showed an improvement in flexibility on neuropsychological assessment directly after CRT, whereas HC did not improve over time. Self-report assessment of flexibility, as well as central coherence, did not show significant improvement after CRT. DISCUSSION: Results suggest that CRT may be beneficial for enhancing flexibility in adolescents with AN. However, randomized controlled studies are essential to determine the actual efficacy of this intervention.

[Feedback on Cognitive Remediation Therapy from Adolescents with Anorexia Nervosa - A Qualitative Study]. / Therapiewahrnehmung der 'Cognitive Remediation Therapy' bei Jugendlichen mit Anorexia nervosa - Eine qualitative Analyse.

BACKGROUND: Cognitive remediation therapy (CRT) is a relatively new therapy for patients with anorexia nervosa (AN). There is an increased demand to include the patient view during the evaluation of treatment programs. So far, there is no structured evaluation of the subjective view of adolescents with AN on CRT available. METHODS: 20 patients with AN between the ages of 12 and 18 years completed 10 CRT sessions. 19 patients (age: 15.6±1.3; BMI-percentile: 2.4±3.5) filled out a feedback questionnaire on their subjective CRT experience. The positive and negative aspects of CRT from a patient's perspective were inducted from the feedback material using the 'Qualitative content analysis' from Mayring, allowing the data to be summarized into different categories. The software program MAXQDA 11 was used for the data analysis. RESULTS: The final category system consisted of 6 general categories, which in turn were summarized into 4 main categories: "general therapy perception", "content specific therapy perception", "relationship to everyday life" and "relationship with CRT therapist". 10 patients described CRT (53%) as 'fun'. 12 patients (63%) noticed positive changes in their everyday lives, which they attributed to their participation in CRT. 4 patients (21%) were not able to notice any changes in their everyday lives. 3 patients (16%) valued the good atmosphere during the CRT sessions and 6 patients (32%) found CRT to be a welcome distraction from their daily lives on the ward. 5 patients (26%) mentioned that CRT was too demanding and that difficulties arose during their reflection on thinking styles. DISCUSSION: Overall, CRT is evaluated positively by adolescent patients with AN. A small number of patients reports difficulties with CRT and experiences CRT as strenuous. This positive evaluation of CRT is in line with results from the few qualitative studies in adults with AN. Due to a potential social desirability bias, the patient's perspective should be interpreted with slight caution. CONCLUSION: CRT is received well by adolescents with AN and poses an interesting, new therapy module in the eating disorder field.

Anti-NMDA receptor encephalitis presenting as atypical anorexia nervosa: an adolescent case report.

Since 2007, more than 600 patients have been diagnosed with anti-N-methyl-D-aspartate (NMDA) receptor encephalitis, with almost 40 % of those affected being children or adolescents. In early phases of the illness, this life-threatening disease is characterized by psychiatric symptoms, such as depression, anxiety, obsessions, hallucinations or delusions. Consequently, a high percentage of patients receive psychiatric diagnoses at first, hindering the crucial early diagnosis and treatment of the anti-NMDA receptor encephalitis. We report on a 15-year-old girl initially presenting with pathological eating behaviour and significant weight loss resulting in an (atypical) anorexia nervosa (AN) diagnosis. Her early course of illness, diagnostic process, treatment and short-term outcome are described. This case report aims to raise awareness about the association between anorectic behaviour and anti-NMDA receptor encephalitis and highlight the importance of multidisciplinary teams in child and adolescent services.

Cognitive Remediation Therapy for Children with Anorexia Nervosa.

OBJECTIVE: Evidence-based treatment programs for children with anorexia nervosa (AN) are scarce, while their prognosis is negative and the incidence rate rises. A new therapeutic approach recently received positive attention: cognitive remediation therapy (CRT). This intervention targets inflexibility and the inability to perceive the bigger picture in persons with AN. So far, studies and case reports have focused on either adolescent or adult patients and less on young children with AN. This case report therefore describes and evaluates the implementation of CRT with a child with AN. METHOD: A 12-year-old girl with severe chronic AN was treated with 10 sessions of CRT. Her clinical and neuropsychological evaluations before, directly after and 7 months after CRT are reported. Additionally, the patient's written and verbal feedbacks are reviewed. RESULTS: At the 7-month follow-up the patient showed a stable healthy weight and reported a reduced presence of psychopathology. Her neuropsychological performance directly after CRT and after 7 months did not improve. CONCLUSIONS: The clinical evaluation of our case report suggests that CRT may be a promising add-on therapy in the clinical treatment of young girls with AN.

[Anorexia nervosa - from a neuroscience perspective]. / Anorexia nervosa. Aktuelle neurowissenschaftliche Befunde.

Anorexia nervosa is a frequent disorder especially among adolescent girls and young women, with high morbidity, mortality, and relapse rates. To date, no single therapeutic approach has proved to be superior to others (Herpertz et al., 2011). It remains unclear how its etiology and pathology are encoded within cognitive, neural, and endocrinological processes that modulate important mechanisms in appetitive processing and weight regulation. Yet, several trait characteristics have been identified in AN which might reflect predisposing factors. Further, altered levels of neuropeptides and hormones that regulate appetite and feeding behavior have been found during both the acute and the recovered state, pointing to dysfunctional mechanisms in AN that persist even after malnutrition has ceased. Researchers are also hoping that brain imaging techniques will allow for a more detailed investigation of the neural basis of reward and punishment sensitivity that appears to be altered in AN. The integration and extension of recent findings in these areas will hopefully provide a more comprehensive understanding of the disorder and hence enable the development of more effective treatments.

Lifetime victimization experiences, depressiveness, suicidality, and feelings of loneliness in youth in care.

BACKGROUND: Research has demonstrated the damaging effects of poly-victimization on the mental health of children and adolescents. However, few studies have been conducted in high-risk youth in care (Y-IC) samples. OBJECTIVE: The study examines the frequency of lifetime victimization and the association of poly-victimization and victimization types on depressiveness, suicidality, and feelings of loneliness among Y-IC. PARTICIPANTS AND SETTING: 164 participants aged 14 and 21 years (M = 17.39, SD = 1.95), who live in family-based care or residential care. METHODS: The Juvenile Victimization Questionnaire (JVQ) was used to assess lifetime victimization. The Patient Health Questionnaire (PHQ-9), and the Loneliness Scale-SOEP (LS-S) to measure depressiveness, suicidality, and loneliness. Hierarchical regression models were calculated. RESULTS: Participants reported on average 12.66 (SD = 6.58) victimization experiences. The female and diverse gender groups reported higher rates of victimization, loneliness, depressiveness, and suicidality than the males. Participants in residential care reported more victimizations and stronger feelings of loneliness than those in family-based care. Poly-victimization was not associated with any of these internalizing symptoms but peer victimization was significantly associated with depressiveness (ß = 0.23, p = .002) and loneliness (ß = 0.22, p = .006), sexual victimization with depressiveness (ß = 0.22, p = .004). CONCLUSION: Y-IC show high levels of victimization and internalizing symptoms, with higher burden on girls and youth living in residential care. Findings underscore the relevance of social exclusion experiences among peers within Y-IC. Interventions should address multiple forms of victimization, with a special focus on sexual and peer victimization.

Impaired flexible reward learning in ADHD patients is associated with blunted reinforcement sensitivity and neural signals in ventral striatum and parietal cortex.

Reward-based learning and decision-making are prime candidates to understand symptoms of attention deficit hyperactivity disorder (ADHD). However, only limited evidence is available regarding the neurocomputational underpinnings of the alterations seen in ADHD. This concerns flexible behavioral adaption in dynamically changing environments, which is challenging for individuals with ADHD. One previous study points to elevated choice switching in adolescent ADHD, which was accompanied by disrupted learning signals in medial prefrontal cortex. Here, we investigated young adults with ADHD (n = 17) as compared to age- and sex-matched controls (n = 17) using a probabilistic reversal learning experiment during functional magnetic resonance imaging (fMRI). The task requires continuous learning to guide flexible behavioral adaptation to changing reward contingencies. To disentangle the neurocomputational underpinnings of the behavioral data, we used reinforcement learning (RL) models, which informed the analysis of fMRI data. ADHD patients performed worse than controls particularly in trials before reversals, i.e., when reward contingencies were stable. This pattern resulted from 'noisy' choice switching regardless of previous feedback. RL modelling showed decreased reinforcement sensitivity and enhanced learning rates for negative feedback in ADHD patients. At the neural level, this was reflected in a diminished representation of choice probability in the left posterior parietal cortex in ADHD. Moreover, modelling showed a marginal reduction of learning about the unchosen option, which was paralleled by a marginal reduction in learning signals incorporating the unchosen option in the left ventral striatum. Taken together, we show that impaired flexible behavior in ADHD is due to excessive choice switching ('hyper-flexibility'), which can be detrimental or beneficial depending on the learning environment. Computationally, this resulted from blunted sensitivity to reinforcement of which we detected neural correlates in the attention-control network, specifically in the parietal cortex. These neurocomputational findings remain preliminary due to the relatively small sample size.