Tackle your Tics, a brief intensive group-based exposure treatment for young people with tics: results of a randomised controlled trial

Tics can have a serious impact on the quality of life of children and their families. Behavioural therapy is an evidence-based first line treatment for tic disorders. This randomised controlled trial studied the efficacy of a brief, condensed group-based programme for children with tics (Dutch Trial Registry NL8052, 27 September 2019). Tackle your Tics is a four-day group treatment, including exposure and response prevention and supporting components, delivered by therapists and 'experts by experience'. We collected outcome measures at baseline (T1), directly post-treatment (T2), and at three- and 6-months follow-up (T3, T4) including tic severity (primary outcome measure), tic-related impairment, quality of life, tic-related cognitions, emotional/behavioural functioning, family functioning, treatment satisfaction and adherence. Outcomes directly post-treatment improved in both the treatment group (n = 52) and waiting list (n = 54), but showed no statistically significant differences between the conditions (differential change over time T1-T2) on tic severity (Yale Global Tic Severity Scale), quality of life (Gilles de la Tourette Syndrome Quality of Life Scale), tic-related cognitions and family functioning. At longer term (T3), again no between-group difference was found on tic severity, but tic-related impairment, quality of life and emotional/behavioural functioning significantly improved in the treatment group compared to the waiting list. Mean treatment satisfaction scores were favourable for both children and parents. Directly posttreatment, Tackle your Tics showed no superior effect compared to waiting list. However, on longer term this brief four-day group treatment was effective in improving tic-related impairment, quality of life and emotional/behavioural functioning.

Long-term methylphenidate exposure and 24-hours blood pressure and left ventricular mass in adolescents and young adults with attention deficit hyperactivity disorder

Young people with attention deficit hyperactivity disorder (ADHD) are now being treated with psychostimulant medication for longer than was previously the case and are increasingly likely to remain on methylphenidate into adolescence and adulthood. This study was designed to determine whether the long-term use of methylphenidate (MPH, immediate release or extended release) increases blood pressure and left ventricular mass (LVM) identified by echocardiography in adolescents and young adults with ADHD aged 12-25 years. In a five-site cross-sectional design two groups were compared for 24- hour blood pressure and heart rate (HR) registrations and LVM: 1) adolescents and young adults with ADHD who had been treated with MPH for > 2 years (N=162, age mean (SD) 15.6 (3.0)), and 2) adolescents and young adults with ADHD who had never been treated with methylphenidate (N=71, age mean 17.4 (4.2)). The analyses were controlled for propensity scores derived from age, sex, height, weight, and 19 relevant background variables. A blood pressure indicative of hypertension (>95th percentile) was observed in 12.2% (95% confidence interval 7.3 - 18.9%) of the participants in the MPH treated group and in 9.6% (95%CI 3.2 - 21.0%) of the MPH naïve group, with overlapping intervals. The 24-hour recorded systolic blood pressure (SBP) and HR were significantly higher during daytime in medicated individuals with ADHD than in those with unmedicated ADHD, but were similar in both groups during the night. 24-hour diastolic blood pressure (DBP) did not differ between both groups during either daytime or at night. LVM, corrected for body-surface area (LVMBSA), also did not differ between the two groups (p=0.20, controlling for confounders). Further, MPH daily dose and duration of treatment were unrelated to LVMBSA, SBP, and DBP. Long-term MPH use in adolescents and young adults with ADHD is associated with small but significant increases of SBP and HR during daytime. Given the current sample size, the proportions of hypertension do not differ significantly between MPH treated and MPH-naïve individuals with ADHD. Future studies with larger samples, longer treatment duration, and/or with within-subject designs are necessary. The results do, however, further support recommendations that highlight the importance of monitoring blood pressure and HR during MPH treatment.

Training is not enough: child and adolescent psychiatry clinicians' impressions of telepsychiatry during the first COVID-19 related lockdown

To ensure the continuity of care during the COVID-19 pandemic, clinicians in Child and Adolescent Psychiatry (CAP) were forced to immediately adapt in-person treatment into remote treatment. This study aimed to examine the effects of pre-COVID-19 training in- and use of telepsychiatry on CAP clinicians' impressions of telepsychiatry during the first two weeks of the Dutch COVID-19 related lockdown, providing a first insight into the preparations necessary for the implementation and provision of telepsychiatry during emergency situations. All clinicians employed by five specialized CAP centres across the Netherlands were invited to fill in a questionnaire that was specifically developed to study CAP clinicians' impressions of telepsychiatry during the COVID-19 pandemic. A total of 1065 clinicians gave informed consent and participated in the study. A significant association was found between pre-COVID-19 training and/or use of telepsychiatry and CAP clinicians' impressions of telepsychiatry. By far, the most favourable impressions were reported by participants that were both trained and made use of telepsychiatry before the pandemic. Participants with either training or use separately reported only slightly more favourable impressions than participants without any previous training or use. The expertise required to provide telepsychiatry is not one-and-the-same as the expertise that is honed through face-to-face consultation. The findings of this study strongly suggest that, separately, both training and (clinical) practice fail to sufficiently support CAP clinicians in the implementation and provision of telepsychiatry. It is therefore recommended that training and (clinical) practice are provided in conjunction.

Exposure to challenging behaviours and burnout symptoms among care staff: the role of psychological resources

BACKGROUND

Staff supporting individuals with intellectual disabilities are at risk of burnout symptoms. Evidence suggests an association between exposure to challenging behaviours of individuals with intellectual disabilities and burnout symptoms of staff, but the protective role of staff psychological resources in this relation has been understudied.

METHOD

We investigated the association between exposure to challenging behaviours and burnout symptoms of staff and the direct and moderating effects of several psychological resources. Staff (N = 1271) completed an online survey concerning burnout symptoms (subscale Emotional Exhaustion of the Maslach Burnout Inventory), exposure to challenging behaviours and a range of potential psychological resources. We examined main and moderating effects with multilevel analyses. In order to control for the multiple comparisons, P values corrected for false discovery rate (PFDR ) were reported.

RESULTS

We found a direct relation between exposure to challenging behaviours and increased levels of burnout symptoms in staff (b = .15, t(670) = 4.466, PFDR  < .0001). Perceived supervisor social support (b = -.97, t(627) = -7.562, PFDR  < .0001), staff self-efficacy (b = -.23, t(673) = -3.583, PFDR  < .0001), resilience (b = -.19, t(668) = -2.086, PFDR  < .05) and extraversion (b = -.20, t(674) = -3.514, PFDR  < .05) were associated with reduced burnout symptoms. None of the proposed psychological resources moderated the association between exposure to challenging behaviours and burnout symptoms of staff.

CONCLUSIONS

Of the psychological resources found to be associated with reduced risk of burnout symptoms, staff self-efficacy and access of staff to supervisor social support seem to be the factors that can be influenced best. These factors thus may be of importance in reducing the risk of developing burnout symptoms and improving staff well-being, even though the current study was not designed to demonstrate causal relations between psychological resources and burnout symptoms.

Tackle your Tics: pilot findings of a brief, intensive group-based exposure therapy program for children with tic disorders

Tourette syndrome (TS) and other chronic tic disorders (CTD) are prevalent neurodevelopmental disorders, which can have a huge burden on families and society. Behavioral treatment is a first-line intervention for tic disorders. Despite demonstrated efficacy, tic reduction and utilization rates of behavioral treatment remain relatively low. Patient associations point to an urgent need for easy-to-undergo treatments that focus both on tic reduction and improvement of quality of life. To enhance treatment outcome and overcome treatment barriers, this pilot study's aim was to investigate the feasibility and preliminary results of a brief, intensive group-based treatment. Tackle your Tics is a 4-day intensive and comprehensive group-based program for children and adolescents (9-17 years) with a tic disorder, consisting of exposure and response prevention (ERP) treatment and additional supporting components, such as coping strategies, relaxing activities and parent support. Assessments were performed pre- and post-treatment and at 2 months follow-up, to test outcomes on tic severity and quality of life, and explore premonitory urges, emotional and behavioral functioning and treatment satisfaction (N = 14, of whom 13 completed the treatment). Parents and children rated this treatment positive on a treatment satisfaction questionnaire. On tic severity (Yale Global Tic Severity Scale) and quality of life (Gilles de la Tourette Syndrome Quality of Life Scale for children and adolescents), improvements between pre-treatment and follow-up were found. Intensive ERP in group format is promising as a feasible treatment to improve both tic severity as well as quality of life. Larger controlled trials are needed to establish its effectiveness.

Non-pharmacological interventions for challenging behaviours of adults with intellectual disabilities: A meta-analysis

BACKGROUND

Non-pharmacological interventions are recommended for the treatment of challenging behaviours in individuals with intellectual disabilities by clinical guidelines. However, evidence for their effectiveness is ambiguous. The aim of the current meta-analysis is to update the existing evidence, to investigate long-term outcome, and to examine whether intervention type, delivery mode, and study design were associated with differences in effectiveness.

METHOD

An electronic search was conducted using the databases Medline, Eric, PsychINFO and Cinahl. Studies with experimental or quasi-experimental designs were included. We performed an overall random-effect meta-analysis and subgroup analyses.

RESULTS

We found a significant moderate overall effect of non-pharmacological interventions on challenging behaviours (d = 0.573, 95% CI [0.352-0.795]), and this effect appears to be longlasting. Interventions combining mindfulness and behavioural techniques showed to be more effective than other interventions. However, this result should be interpreted with care due to possible overestimation of the subgroup analysis. No differences in effectiveness were found across assessment times, delivery modes or study designs.

CONCLUSIONS

Non-pharmacological interventions appear to be moderately effective on the short and long term in reducing challenging behaviours in adults with intellectual disabilities.

Psychosocial risk factors for suicidality in children and adolescents

Suicidality in childhood and adolescence is of increasing concern. The aim of this paper was to review the published literature identifying key psychosocial risk factors for suicidality in the paediatric population. A systematic two-step search was carried out following the PRISMA statement guidelines, using the terms 'suicidality, suicide, and self-harm' combined with terms 'infant, child, adolescent' according to the US National Library of Medicine and the National Institutes of Health classification of ages. Forty-four studies were included in the qualitative synthesis. The review identified three main factors that appear to increase the risk of suicidality: psychological factors (depression, anxiety, previous suicide attempt, drug and alcohol use, and other comorbid psychiatric disorders); stressful life events (family problems and peer conflicts); and personality traits (such as neuroticism and impulsivity). The evidence highlights the complexity of suicidality and points towards an interaction of factors contributing to suicidal behaviour. More information is needed to understand the complex relationship between risk factors for suicidality. Prospective studies with adequate sample sizes are needed to investigate these multiple variables of risk concurrently and over time.

[Dilemmas in discontinuation of antipsychotic drug use in people with intellectual disabilities]

The prevalence of antipsychotic drug use in people with intellectual disability (id) is high and largely off-label for challenging behaviour (cb), while evidence for their efficacy lacks. Side-effects frequently occur. Guidelines recommend appropriate psychotropic drug use by monitoring of effects and side-effects and discontinuing off-label use for cb. However, they are insufficiently adhered to. Discontinuation often fails due to behavioural worsening by largely unknown causes.<br/> AIM: To offer an overview of results of off-label antipsychotic drug discontinuation and determinants for success or failure.<br/> METHOD: Literature search in Medline, embase and Psycinfo.<br/> RESULTS: Prospective open-label studies show that discontinuation in selected populations is possible in 33-40% and in placebo-controlled studies in 55-82%. Challenging behaviours, as measured with a standardized scale, mostly remained similar in those who succeeded as well as in those who failed to discontinue. Health problems, extrapyramidal symptoms, higher antipsychotic drug dosage, more severe cb, autism and male gender in participants, negative emotions towards cb, less knowledge on psychotropic drugs and male gender of support professional were related to less chance of successful discontinuation.<br/> CONCLUSION: To improve results of antipsychotic drug discontinuation, proper diagnostics of underlying causes for cb, involvement of all stakeholders and enhancement of treatment opportunities for psychopathology in people with id are needed. Integrative care and knowledge development of id- and mental health care may be helpful.

Is risperidone effective in reducing challenging behaviours in individuals with intellectual disabilities after 1 year or longer use? A placebo-controlled, randomised, double-blind discontinuation study

BACKGROUND

Many people with intellectual disabilities use risperidone long term for the management of challenging behaviours, despite its limited proof of effectiveness and its clear association with adverse events. Therefore, this study aimed to investigate the effectiveness of ongoing treatment with risperidone in reducing challenging behaviours versus controlled discontinuation on behaviour and health parameters.

METHOD

This was a placebo-controlled, double-blind, randomised discontinuation trial of risperidone. In the discontinuation group, risperidone was gradually replaced by a placebo over 14 weeks, while the control group maintained their existing dosage. Eight weeks after discontinuation, behaviour (as measured by the 'Aberrant Behavior Checklist') and health parameters (dyskinesia, akathisia, parkinsonism, weight, waist circumference, sedation and laboratory outcomes) were compared in both groups.

RESULTS

A total of 25 participants were included in the trial, of which 11 were randomised into the discontinuation group and 14 were randomised into the continued treatment group. In the discontinuation group, 82% completely withdrew from risperidone. There was no significant change in irritability, compared with the continuation group, although there was a Group*Time effects on stereotypical behaviour in favour of the continuation group. Significant Group*Time effects were also found for weight, waist, body mass index, prolactin levels and testosterone levels, with beneficial effects for the discontinuation group.

CONCLUSION

Discontinuation of long-term risperidone for reducing challenging behaviours is possible, without an increase in irritability. Discontinuation of risperidone may have beneficial effects on weight, waist circumference, prolactin levels and testosterone levels. The study suffered from difficulties in achieving the required sample size, which affected study power and generalizability.

A Potential Role for the STXBP5-AS1 Gene in Adult ADHD Symptoms

We aimed to detect Attention-deficit/hyperactivity (ADHD) risk-conferring genes in adults. In children, ADHD is characterized by age-inappropriate levels of inattention and/or hyperactivity-impulsivity and may persists into adulthood. Childhood and adulthood ADHD are heritable, and are thought to represent the clinical extreme of a continuous distribution of ADHD symptoms in the general population. We aimed to leverage the power of studies of quantitative ADHD symptoms in adults who were genotyped. Within the SAGA (Study of ADHD trait genetics in adults) consortium, we estimated the single nucleotide polymorphism (SNP)-based heritability of quantitative self-reported ADHD symptoms and carried out a genome-wide association meta-analysis in nine adult population-based and case-only cohorts of adults. A total of n = 14,689 individuals were included. In two of the SAGA cohorts we found a significant SNP-based heritability for self-rated ADHD symptom scores of respectively 15% (n = 3656) and 30% (n = 1841). The top hit of the genome-wide meta-analysis (SNP rs12661753; p-value = 3.02 × 10^-7) was present in the long non-coding RNA gene STXBP5-AS1. This association was also observed in a meta-analysis of childhood ADHD symptom scores in eight population-based pediatric cohorts from the Early Genetics and Lifecourse Epidemiology (EAGLE) ADHD consortium (n = 14,776). Genome-wide meta-analysis of the SAGA and EAGLE data (n = 29,465) increased the strength of the association with the SNP rs12661753. In human HEK293 cells, expression of STXBP5-AS1 enhanced the expression of a reporter construct of STXBP5, a gene known to be involved in "SNAP" (Soluble NSF attachment protein) Receptor" (SNARE) complex formation. In mouse strains featuring different levels of impulsivity, transcript levels in the prefrontal cortex of the mouse ortholog Gm28905 strongly correlated negatively with motor impulsivity as measured in the five choice serial reaction time task (r² = - 0.61; p = 0.004). Our results are consistent with an effect of the STXBP5-AS1 gene on ADHD symptom scores distribution and point to a possible biological mechanism, other than antisense RNA inhibition, involved in ADHD-related impulsivity levels.

Evaluating Sex and Age Differences in ADI-R and ADOS Scores in a Large European Multi-site Sample of Individuals with Autism Spectrum Disorder

Research on sex-related differences in Autism Spectrum Disorder (ASD) has been impeded by small samples. We pooled 28 datasets from 18 sites across nine European countries to examine sex differences in the ASD phenotype on the ADI-R (376 females, 1763 males) and ADOS (233 females, 1187 males). On the ADI-R, early childhood restricted and repetitive behaviours were lower in females than males, alongside comparable levels of social interaction and communication difficulties in females and males. Current ADI-R and ADOS scores showed no sex differences for ASD severity. There were lower socio-communicative symptoms in older compared to younger individuals. This large European ASD sample adds to the literature on sex and age variations of ASD symptomatology.

Physicians' reasons not to discontinue long-term used off-label antipsychotic drugs in people with intellectual disability

BACKGROUND

People with intellectual disability (ID) frequently use antipsychotic drugs on an off-label base, often for many years. Physicians' decisions to discontinue these drugs not only depend on patient characteristics, like the presence of mental or behavioural disorders, but also on environmental factors, such as inappropriate living circumstances, and on attitudes, knowledge and beliefs of staff, clients and their representatives towards the effects of antipsychotic drug use. In this study, we therefore investigated the influence of participant and setting-related factors on decisions of physicians not to discontinue off-label prescribed antipsychotics.

METHODS

The study took place in living facilities of six service providers for people with ID spread over the Netherlands and staffed with support professionals, nurses, behavioural scientist and physicians and was part of an antipsychotics discontinuation trial. ID physicians had to decide whether the off-label use of antipsychotics could be discontinued. Medical and pharmaceutical records were used to establish the prevalence of antipsychotic drug use in the study population, along with duration of use and whether the use was off-label. Reasons of physicians not to discontinue the prescription of antipsychotics in those participants who used off-label antipsychotics for more than a year were collected and categorised as related to participant or setting characteristics, including lack of consent to discontinue, and staff members, participants or their legal representatives.

RESULTS

Of the 3299 clients of the service providers, 977 used one or more antipsychotic drugs. The prevalence of antipsychotic drug use was 30%. Reasons for use were in 5% of cases, a chronic psychotic disorder classified according to Diagnostic System Mental Disorders, Fourth Edition, criteria, in 25%, present or past (suspected) non-schizophrenia-related psychotic symptoms and in 69%, challenging behaviours. Overall, physicians were willing to discontinue their prescriptions in 51% of cases, varying from 22% to 87% per service provider. The odds for decisions of physicians to discontinue off-label prescriptions varied from 0.19 to 13.95 per service provider. The variables 'a living situation with care and support' and 'challenging behaviour' were associated with a higher chance of discontinuation. The main reasons for decisions not to discontinue were concerns for symptoms of restlessness, the presence of an autism spectrum disorder, previously unsuccessful attempts to discontinue and objections against discontinuation of legal representatives. Reasons for physicians' decisions not to discontinue the off-label use of antipsychotics varied largely between the service providers.

CONCLUSIONS

The prevalence of antipsychotic drug use for off-label indications in people with ID remains high. The results of this study indicate that there is a large variation in clinical practice of physicians regarding discontinuation of long-term antipsychotic drug prescriptions, which may be partially related to environmental factors as setting culture and attitudes of staff towards off-label antipsychotic drug use in persons with ID.

Predicting attention-deficit/hyperactivity disorder severity from psychosocial stress and stress-response genes: a random forest regression approach

Identifying genetic variants contributing to attention-deficit/hyperactivity disorder (ADHD) is complicated by the involvement of numerous common genetic variants with small effects, interacting with each other as well as with environmental factors, such as stress exposure. Random forest regression is well suited to explore this complexity, as it allows for the analysis of many predictors simultaneously, taking into account any higher-order interactions among them. Using random forest regression, we predicted ADHD severity, measured by Conners' Parent Rating Scales, from 686 adolescents and young adults (of which 281 were diagnosed with ADHD). The analysis included 17 374 single-nucleotide polymorphisms (SNPs) across 29 genes previously linked to hypothalamic-pituitary-adrenal (HPA) axis activity, together with information on exposure to 24 individual long-term difficulties or stressful life events. The model explained 12.5% of variance in ADHD severity. The most important SNP, which also showed the strongest interaction with stress exposure, was located in a region regulating the expression of telomerase reverse transcriptase (TERT). Other high-ranking SNPs were found in or near NPSR1, ESR1, GABRA6, PER3, NR3C2 and DRD4. Chronic stressors were more influential than single, severe, life events. Top hits were partly shared with conduct problems. We conclude that random forest regression may be used to investigate how multiple genetic and environmental factors jointly contribute to ADHD. It is able to implicate novel SNPs of interest, interacting with stress exposure, and may explain inconsistent findings in ADHD genetics. This exploratory approach may be best combined with more hypothesis-driven research; top predictors and their interactions with one another should be replicated in independent samples.

Development and psychometric properties of the Suicidality: Treatment Occurring in Paediatrics (STOP) Suicidality Assessment Scale (STOP-SAS) in children and adolescents

BACKGROUND

To create a self-reported, internet-based questionnaire for the assessment of suicide risk in children and adolescents.

METHODS

As part of the EU project 'Suicidality: Treatment Occurring in Paediatrics' (STOP project), we developed web-based Patient Reported Outcome Measures (PROMs) for children and adolescents and for proxy reports by parents and clinicians in order to assess suicidality. Based on a literature review, expert panels and focus groups of patients, we developed the items of the STOP Suicidality Assessment Scale (STOP-SAS) in Spanish and English, translated it into four more languages, and optimized it for web-based presentation using the HealthTracker^TM platform. Of the total 19 questions developed for the STOP-SAS, four questions that assess low-level suicidality were identified as screening questions (three of them for use with children, and all four for use with adolescents, parents and clinicians). A total of 395 adolescents, 110 children, 637 parents and 716 clinicians completed the questionnaire using the HealthTracker^TM, allowing us to evaluate the internal consistency and convergent validity of the STOP-SAS with the clinician-rated Columbia Suicide Severity Rating Scale (C-SSRS). Validity was also assessed with the receiver operating characteristic (ROC) area of the STOP-SAS with the C-SSRS.

RESULTS

The STOP-SAS comprises 19 items in its adolescent, parent, and clinician versions, and 14 items in its children's version. Good internal consistency was found for adolescents (Cronbach's alpha: 0.965), children (Cronbach's alpha: 0.922), parents (Cronbach's alpha: 0.951) and clinicians (Cronbach's alpha: 0.955) versions. A strong correlation was found between the STOP-SAS and the C-SSRS for adolescents (r:0.670), parents (r:0.548), clinicians (r:0.863) and children (r:0.654). The ROC area was good for clinicians' (0.917), adolescents' (0.834) and parents' (0.756) versions but only fair (0.683) for children's version.

CONCLUSIONS

The STOP-SAS is a comprehensive, web-based PROM developed on the HealthTracker^TM platform, and co-designed for use by adolescents, children, parents and clinicians. It allows the evaluation of aspects of suicidality and shows good reliability and validity.

An explorative study of school performance and antipsychotic medication

BACKGROUND

Antipsychotic therapy can reduce severe symptoms of psychiatric disorders, however, data on school performance among children on such treatment are lacking. The objective was to explore school performance among children using antipsychotic drugs at the end of primary education.

METHODS

A cross-sectional study was conducted using the University Groningen pharmacy database linked to academic achievement scores at the end of primary school (Dutch Cito-test) obtained from Statistics Netherlands. Mean Cito-test scores and standard deviations were obtained for children on antipsychotic therapy and reference children, and statistically compared using analyses of covariance. In addition, differences in subgroups as boys versus girls, ethnicity, household income, and late starters (start date within 12 months of the Cito-test) versus early starters (start date > 12 months before the Cito-test) were tested.

RESULTS

In all, data from 7994 children could be linked to Cito-test scores. At the time of the Cito-test, 45 (0.6 %) were on treatment with antipsychotics. Children using antipsychotics scored on average 3.6 points lower than the reference peer group (534.5 ± 9.5). Scores were different across gender and levels of household income (p < 0.05). Scores of early starters were significantly higher than starters within 12 months (533.7 ± 1.7 vs. 524.1 ± 2.6).

CONCLUSION

This first exploration showed that children on antipsychotic treatment have lower school performance compared to the reference peer group at the end of primary school. This was most noticeable for girls, but early starters were less affected than later starters. Due to the observational cross-sectional nature of this study, no causality can be inferred, but the results indicate that school performance should be closely monitored and causes of underperformance despite treatment warrants more research.

Interplay between stress response genes associated with attention-deficit hyperactivity disorder and brain volume

The glucocorticoid receptor plays a pivotal role in the brain's response to stress; a haplotype of functional polymorphisms in the NR3C1 gene encoding this receptor has been associated with attention-deficit hyperactivity disorder (ADHD). The serotonin transporter (5-HTT) gene polymorphism 5-HTTLPR is known to influence the relation between stress exposure and ADHD severity, which may be partly because of its reported effects on glucocorticoid levels. We therefore investigated if NR3C1 moderates the relation of stress exposure with ADHD severity and brain structure, and the potential role of 5-HTTLPR. Neuroimaging, genetic and stress exposure questionnaire data were available for 539 adolescents and young adults participating in the multicenter ADHD cohort study NeuroIMAGE (average age: 17.2 years). We estimated the effects of genetic variation in NR3C1 and 5-HTT, stress exposure and their interactions on ADHD symptom count and gray matter volume. We found that individuals carrying the ADHD risk haplotype of NR3C1 showed significantly more positive relation between stress exposure and ADHD severity than non-carriers. This gene-environment interaction was significantly stronger for 5-HTTLPR L-allele homozygotes than for S-allele carriers. These two- and three-way interactions were reflected in the gray matter volume of the cerebellum, parahippocampal gyrus, intracalcarine cortex and angular gyrus. Our findings illustrate how genetic variation in the stress response pathway may influence the effects of stress exposure on ADHD severity and brain structure. The reported interplay between NR3C1 and 5-HTT may further explain some of the heterogeneity between studies regarding the role of these genes and hypothalamic-pituitary-adrenal axis activity in ADHD.

Adolescent behavioral and neural reward sensitivity: a test of the differential susceptibility theory

Little is known about the causes of individual differences in reward sensitivity. We investigated gene-environment interactions (GxE) on behavioral and neural measures of reward sensitivity, in light of the differential susceptibility theory. This theory states that individuals carrying plasticity gene variants will be more disadvantaged in negative, but more advantaged in positive environments. Reward responses were assessed during a monetary incentive delay task in 178 participants with and 265 without attention-deficit/hyperactivity disorder (ADHD), from N=261 families. We examined interactions between variants in candidate plasticity genes (DAT1, 5-HTT and DRD4) and social environments (maternal expressed emotion and peer affiliation). HTTLPR short allele carriers showed the least reward speeding when exposed to high positive peer affiliation, but the most when faced with low positive peer affiliation or low maternal warmth. DAT1 10-repeat homozygotes displayed similar GxE patterns toward maternal warmth on general task performance. At the neural level, DRD4 7-repeat carriers showed the least striatal activation during reward anticipation when exposed to high maternal warmth, but the most when exposed to low warmth. Findings were independent of ADHD severity. Our results partially confirm the differential susceptibility theory and indicate the importance of positive social environments in reward sensitivity and general task performance for persons with specific genotypes.

Influence of DAT1 and COMT variants on neural activation during response inhibition in adolescents with attention-deficit/hyperactivity disorder and healthy controls

BACKGROUND

Impairment of response inhibition has been implicated in attention-deficit/hyperactivity disorder (ADHD). Dopamine neurotransmission has been linked to the behavioural and neural correlates of response inhibition. The current study aimed to investigate the relationship of polymorphisms in two dopamine-related genes, the catechol-O-methyltransferase gene (COMT) and the dopamine transporter gene (SLC6A3 or DAT1), with the neural and behavioural correlates of response inhibition.

METHOD

Behavioural and neural measures of response inhibition were obtained in 185 adolescents with ADHD, 111 of their unaffected siblings and 124 healthy controls (mean age 16.9 years). We investigated the association of DAT1 and COMT variants on task performance and whole-brain neural activation during response inhibition in a hypothesis-free manner. Additionally, we attempted to explain variance in previously found ADHD effects on neural activation during response inhibition using these DAT1 and COMT polymorphisms.

RESULTS

The whole-brain analyses demonstrated large-scale neural activation changes in the medial and lateral prefrontal, subcortical and parietal regions of the response inhibition network in relation to DAT1 and COMT polymorphisms. Although these neural activation changes were associated with different task performance measures, no relationship was found between DAT1 or COMT variants and ADHD, nor did variants in these genes explain variance in the effects of ADHD on neural activation.

CONCLUSIONS

These results suggest that dopamine-related genes play a role in the neurobiology of response inhibition. The limited associations between gene polymorphisms and task performance further indicate the added value of neural measures in linking genetic factors and behavioural measures.

Combined stimulant and antipsychotic treatment in adolescents with attention-deficit/hyperactivity disorder: a cross-sectional observational structural MRI study

Meta-analyses suggest normalizing effects of methylphenidate on structural fronto-striatal abnormalities in patients with attention-deficit/hyperactivity disorder (ADHD). A subgroup of patients receives atypical antipsychotics concurrent with methylphenidate. Long-term safety and efficacy of combined treatment are unknown. The current study provides an initial investigation of structural brain correlates of combined methylphenidate and antipsychotic treatment in patients with ADHD. Structural magnetic resonance imaging was obtained in 31 patients who had received combined methylphenidate and antipsychotic treatment, 31 matched patients who had received methylphenidate but not antipsychotics, and 31 healthy controls (M age 16.7 years). We analyzed between-group effects in total cortical and subcortical volume, and in seven frontal cortical and eight subcortical-limbic volumes of interest, each involved in dopaminergic neurotransmission. Patients in the combined treatment group, but not those in the methylphenidate only group, showed a reduction in total cortical volume compared to healthy controls (Cohen's d = 0.69, p < 0.004), which was apparent in most frontal volumes of interest. Further, the combined treatment group, but not the methylphenidate group, showed volume reduction in bilateral ventral diencephalon (Left Cohen's d = 0.48, p < 0.04; Right Cohen's d = 0.46, p < 0.05) and the left thalamus (Cohen's d = 0.47, p < 0.04). These findings may indicate antipsychotic treatment counteracting the normalizing effects of methylphenidate on brain structure. However, it cannot be ruled out that pre-existing clinical differences between both patient groups may have resulted in anatomical differences at the time of scanning. The absence of an untreated ADHD group hinders unequivocal interpretation and implications of our findings.

[New impulses for tic research through international collaboration]

BACKGROUND

A section of the UMCG Child and Adolescent Psychiatry Department is currently focusing much of its research on tic disorders.

AIM

To provide an overview of the research projects on tic disorders being currently undertaken at our center.

METHOD

We discuss our research projects giving particular attention to factors that are restricting current research.

RESULTS

The first project is TIC Genetics, a project involving international collaboration. The researchers are looking for rare genetic variants in several family members who have tics and for new gene mutations in children who have tics but no family history of tics. TIC Genetics also investigates the interactions between genes and the environment. A second large-scale longitudinal project, the European Multicentre Tics in Children Study (EMTICS), is focusing on the interplay between genetics, auto-immunity, and environmental factors as a possible cause for the onset and exacerbation of tics. Finally, TS-EUROTRAIN is a European collaboration that concentrates on genetics, neuro-imaging and animal models.

CONCLUSION

International collaborations are essential if we are to acquire a deeper understanding of the etiology of tic disorders.

Attention deficit hyperactivity disorder (ADHD) and executive functioning in affected and unaffected adolescents and their parents: challenging the endophenotype construct

BACKGROUND

The results of twin and sibling studies suggest that executive functioning is a prime candidate endophenotype in attention deficit hyperactivity disorder (ADHD). However, studies have not assessed the co-segregation of executive function (EF) deficits from parents to offspring directly, and it is unclear whether executive functioning is an ADHD endophenotype in adolescents, given the substantial changes in prefrontal lobe functioning, EF and ADHD symptoms during adolescence.

METHOD

We recruited 259 ADHD and 98 control families with an offspring average age of 17.3 years. All participants were assessed for ADHD and EF [inhibition, verbal (VWM) and visuospatial working memory (VsWM)]. Data were analysed using generalized estimating equations (GEEs).

RESULTS

Parental ADHD was associated with offspring ADHD and parental EF was associated with offspring EF but there were no cross-associations (parental ADHD was not associated with offspring EF or vice versa). Similar results were found when siblings were compared. EF deficits were only found in affected adolescents and not in their unaffected siblings or (un)affected parents.

CONCLUSIONS

The core EFs proposed to be aetiologically related to ADHD, that is working memory and inhibition, seem to be aetiologically independent of ADHD in adolescence. EF deficits documented in childhood in unaffected siblings were no longer present in adolescence, suggesting that children 'grow out' of early EF deficits. This is the first study to document ADHD and EF in a large family sample with adolescent offspring. The results suggest that, after childhood, the majority of influences on ADHD are independent from those on EF. This has potential implications for current aetiological models of causality in ADHD.

Effects of controlled discontinuation of long-term used antipsychotics for behavioural symptoms in individuals with intellectual disability

BACKGROUND

Antipsychotics are frequently and often long-term used for challenging behaviour in persons with intellectual disability (ID), but the evidence base for this is meagre. As these agents may cause harmful side effects, discontinuation should be considered. Previous studies regarding discontinuation of long-term used antipsychotics mostly were uncontrolled and involved small numbers. The primary objective was to investigate the effects of controlled discontinuation of antipsychotics prescribed for challenging behaviour. Secondary objectives were to compare the results of two discontinuation time schedules, to compare groups of participants who had and had not achieved complete discontinuation, and to identify patient and medication characteristics that might predict the outcomes. Our hypothesis was that discontinuation of antipsychotics used for behavioural symptoms would not lead to worsening in behaviour.

METHODS

This was a multi-centre parallel-group study comparing two discontinuation schedules of 14 and 28 weeks. Allocation to the two discontinuation schedules took place in a 1:1 ratio. Antipsychotics were tapered off every 2 or 4 weeks with approximately 12.5% of the initial dosage. Follow-up was 12 weeks after the scheduled complete discontinuation, that is, 26 or 40 weeks after the first dose reduction, respectively. Discontinuation was stopped in case of significant behavioural worsening. Participants were 98 residents with ID of three care providing organisations in the Netherlands, aged 15-66 year, who had used for more than 1 year one or more of the six most frequently prescribed antipsychotics for challenging behaviour. Main outcome measure was the total score of the Aberrant Behaviour Checklist (ABC); also ABC sub-scales were used.

RESULTS

Of 98 participants, 43 achieved complete discontinuation; at follow-up 7 had resumed use of antipsychotics. Mean ABC ratings improved significantly for those who achieved complete discontinuation (directly after discontinuation, P < 0.01 and at follow-up, P = 0.03), and at follow-up (P = 0.03) for those who had not achieved complete discontinuation. Similar results were found with respect to most ABC sub-scales, including the 'irritability' sub-scale. There were no significant differences in improvement of ABC ratings between both discontinuation schedules. Higher ratings of extrapyramidal and autonomic symptoms at baseline were associated with less improvement of behavioural symptoms after discontinuation; higher baseline ABC rating predicted higher odds of incomplete discontinuation.

CONCLUSIONS

Discontinuation of antipsychotics prescribed for challenging behaviour in patients with ID is associated with improved behavioural functioning. There is no need to taper off in a time frame longer than 14 weeks.

Emotional development in children with tics: a longitudinal population-based study

Children with tics often experience accompanying problems that may have more impact on their well being and quality of life than the tics themselves. The present study investigates characteristics and the course of associated problems. In a population-based follow-up study, we investigated the developmental trajectory of children with and without tics when they were 7-9 years old. Parents and teachers completed the strengths and difficulties questionnaire (SDQ) when the children were 7-9 years (wave 1) and 4 years later (wave 2). Using strict criteria, we identified 38 children with tics in the cohort of 4,025 children (0.94% of the total cohort) with a preponderance of boys (78.9%). 22 children (57.9%) in the group with tics had only motor tics, and 16 (42.1%) had both motor and vocal tics. Children with tics had significantly higher parent- and teacher-rated SDQ total difficulty scores and subscale scores in both waves. Children with tics experienced an increase in emotional problems and in peer problems between the first and the second wave. This study in a general population indicates that the presence of tics is associated with a range of internalizing and externalizing difficulties, as well as problems in peer relationships. Moreover, our study indicates that emotional and peer problems tend to increase over time in the group of children with tics.

PDD symptoms in ADHD, an independent familial trait?

The aims of this study were to investigate whether subtle PDD symptoms in the context of ADHD are transmitted in families independent of ADHD, and whether PDD symptom familiality is influenced by gender and age. The sample consisted of 256 sibling pairs with at least one child with ADHD and 147 healthy controls, aged 5-19 years. Children who fulfilled criteria for autistic disorder were excluded. The Children's Social Behavior Questionnaire (CSBQ) was used to assess PDD symptoms. Probands, siblings, and controls were compared using analyses of variance. Sibling correlations were calculated for CSBQ scores after controlling for IQ, ADHD, and comorbid anxiety. In addition, we calculated cross-sibling cross-trait correlations. Both children with ADHD and their siblings had higher PDD levels than healthy controls. The sibling correlation was 0.28 for the CSBQ total scale, with the CSBQ stereotyped behavior subscale showing the strongest sibling correlation (r = 0.35). Sibling correlations remained similar in strength after controlling for IQ and ADHD, and were not confounded by comorbid anxiety. Sibling correlations were higher in female than in male probands. The social subscale showed stronger sibling correlations in elder than in younger sibling pairs. Cross-sibling cross-trait correlations for PDD and ADHD were weak and not-significant. The results confirm that children with ADHD have high levels of PDD symptoms, and further suggest that the familiality of subtle PDD symptoms in the context of ADHD is largely independent from ADHD familiality.

Neurobiology and neuroimmunology of Tourette?s syndrome: an update

Tourette's syndrome is a childhood-onset neuropsychiatric disorder characterized by the presence of both multiple motor and vocal tics. While the pathogenesis at a molecular and cellular level remains unknown, structural and functional neuroimaging studies point to the involvement of the basal ganglia and related cortico-striato-thalamo-cortical circuits as the neuroanatomical site for Tourette's syndrome. Moreover, Tourette's syndrome has a strong genetic component, and considerable progress has been made in understanding the mode of transmission and in identifying potential genomic loci. Summaries of recent findings in these areas will be reviewed, followed by a critical overview of findings both supporting and challenging the proposed autoimmune hypothesis of Tourette's syndrome. We conclude that Tourette's syndrome is a heterogeneous disorder, and that immune factors may indeed be involved in some patients.

Is Tourette's syndrome an autoimmune disease?

We provide a review of recent research findings which support the involvement of autoimmunity in childhood-onset tic disorders, in particular the presence of antineuronal autoantibodies, D8/17 B lymphocyte overexpression, a marker of chorea associated with streptococcal infection, and possible beneficial effects of immunomodulatory intervention. One of the most controversial areas in this field is the validity of the proposed PANDAS concept. Some researchers have delineated a putatively unique subgroup of patients, from the spectrum of illness encompassing Tourette's syndrome and obsessive-compulsive disorder (OCD), whose tics and obsessive-compulsive symptoms are shown to arise in response to beta-hemolytic streptococcal infections. They designated it by the term pediatric autoimmune neuropsychiatric disorders associated with streptococcal infections (PANDAS). Herein we additionally present pros and cons concerning the concept of PANDAS. Finally, recommendations for future research directions are given.

Elevated D8/17 expression on B lymphocytes, a marker of rheumatic fever, measured with flow cytometry in tic disorder patients

OBJECTIVE

Elevated D8/17 expression on B lymphocytes is a known susceptibility marker of rheumatic fever. Previous studies have reported higher than usual D8/17 expression on B lymphocytes of patients with tic disorders. The purpose of this study was to assess D8/17 expression on B lymphocytes of tic disorder patients by using an objective method in which no operator variability was involved.

METHOD

D8/17 expression on B lymphocytes was assessed with flow cytometry by using an immunoglobulin M (IgM) monoclonal D8/17-specific antibody in an unselected group of Dutch patients with tic disorders (N=33) and healthy volunteers (N=20). Binding of this monoclonal antibody was compared with binding of an irrelevant IgM monoclonal antibody, and the shift in mean fluorescence intensity of the D8/17-specific antibody compared to that of the irrelevant IgM monoclonal antibody was used as a measure of D8/17 overexpression. For the patients, Yale Global Tic Severity Scale scores were used to assess disease severity.

RESULTS

D8/17 overexpression in the patient group (mean=16.8 arbitrary units, SD=30.5) was significantly higher than in the comparison group (mean=3.2, SD=3.0). A significant minority of the patients (N=13, 39.4%), however, had levels of D8/17 overexpression within the range of that of the healthy comparison subjects. Flow cytometric analysis did not indicate a separate subpopulation of D8/17-positive B cells.

CONCLUSIONS

These data confirm the utility of D8/17 B cell overexpression as a peripheral blood marker in patients with tic disorders and are compatible with a streptococcus-related pathogenesis for at least a subgroup of patients with tic disorders.