Differences in social brain function in autism spectrum disorder are linked to the serotonin transporter: A randomised placebo-controlled single-dose crossover trial.

BACKGROUND: Alterations in the serotonergic control of brain pathways responsible for facial emotion processing in people with autism spectrum disorder (ASD) may be a target for intervention. However, the molecular underpinnings of autistic-neurotypical serotonergic differences are challenging to access in vivo. Receptor-Enriched Analysis of functional Connectivity by Targets (REACT) has helped define molecular-enriched functional magnetic resonance imaging (fMRI) brain networks based on a priori information about the spatial distribution of neurochemical systems from available PET templates. METHODS: We used REACT to estimate the dominant fMRI signal related to the serotonin (5-HT) transporter (SERT) distribution during processing of aversive facial emotion in adults with and without ASD. We first predicted a group difference in baseline (placebo) functioning of this system. We next used a single 20 mg oral dose of citalopram, a serotonin reuptake inhibitor, to test the hypothesis that network activity in people with and without ASD would respond differently to inhibition of SERT. To confirm the specificity of our findings, we also repeated the analysis with 5-HT1A, 5-HT1B, 5-HT2A and 5-HT4 receptor maps. RESULTS: Using REACT with the SERT map, we found a baseline group difference in the SERT-enriched response to faces in the ventromedial prefrontal cortex. A single oral dose of citalopram 'shifted' the response in the ASD group towards the neurotypical baseline but did not alter response in the control group. Similar differences in SERT-enriched response were observed after controlling for other 5-HT maps. CONCLUSIONS: Our findings suggest that the SERT-enriched functional network is dynamically different in ASD during processing of socially relevant stimuli. Whether this acute neurobiological response to citalopram in ASD translates to a clinical target will be an important next step.

Modulation of atypical brain activation during executive functioning in autism: a pharmacological MRI study of tianeptine.

BACKGROUND: Autism spectrum disorder (ASD) is associated with deficits in executive functioning (EF), and these have been suggested to contribute to core as well as co-occurring psychiatric symptoms. The biological basis of these deficits is unknown but may include the serotonergic system, which is involved both in regulating EF in neurotypical populations and in the pathophysiology of ASD. We previously demonstrated that reducing serotonin by acute tryptophan depletion (ATD) shifts differences in brain function during performance of EF tasks towards control levels. However, ATD cannot be easily used in the clinic, and we therefore need to adopt alternative approaches to challenge the serotonin system. Hence, we investigated the role of the serotonergic modulator tianeptine on EF networks in ASD. METHOD: We conducted a pharmacological magnetic resonance imaging study, using a randomized double-blind crossover design, to compare the effect of an acute dosage of 12.5 mg tianeptine and placebo on brain activation during two EF tasks (of response inhibition and sustained attention) in 38 adult males: 19 with ASD and 19 matched controls. RESULTS: Under placebo, compared to controls, individuals with ASD had atypical brain activation in response inhibition regions including the inferior frontal cortex, premotor regions and cerebellum. During sustained attention, individuals with ASD had decreased brain activation in the right middle temporal cortex, right cuneus and left precuneus. Most of the case-control differences in brain function observed under placebo conditions were abolished by tianeptine administration. Also, within ASD individuals, brain functional differences were shifted significantly towards control levels during response inhibition in the inferior frontal and premotor cortices. LIMITATIONS: We conducted a pilot study using a single dose of tianeptine, and therefore, we cannot comment on long-term outcome. CONCLUSIONS: Our findings provide the first evidence that tianeptine can shift atypical brain activation during EF in adults with ASD towards control levels. Future studies should investigate whether this shift in the biology of ASD is maintained after prolonged treatment with tianeptine and whether it improves clinical symptoms.

Serotonin differentially modulates the temporal dynamics of the limbic response to facial emotions in male adults with and without autism spectrum disorder (ASD): a randomised placebo-controlled single-dose crossover trial.

Emotion processing-including signals from facial expressions-is often altered in individuals with autism spectrum disorder (ASD). The biological basis of this is poorly understood but may include neurochemically mediated differences in the responsivity of key 'limbic' regions (including amygdala, ventromedial prefrontal cortex (vmPFC) and nucleus accumbens (NAc)). Emerging evidence also suggests that ASD may be a disorder of brain temporal dynamics. Moreover, serotonin (5-HT) has been shown to be a key regulator of both facial-emotion processing and brain dynamics, and 5-HT abnormalities have been consistently implicated in ASD. To date, however, no one has examined how 5-HT influences the dynamics of facial-emotion processing in ASD. Therefore, we compared the influence of 5-HT on the responsivity of brain dynamics during facial-emotion processing in individuals with and without ASD. Participants completed a facial-emotion processing fMRI task at least 8 days apart using a randomised double-blind crossover design. At each visit they received either a single 20-mg oral dose of the selective serotonin reuptake inhibitor (SSRI) citalopram or placebo. We found that citalopram (which increases levels of 5-HT) caused sustained activation in key limbic regions during processing of negative facial emotions in adults with ASD-but not in neurotypical adults. The neurotypical adults' limbic response reverted more rapidly to baseline following a 5-HT-challenge. Our results suggest that serotonergic homoeostatic control of the temporal dynamics in limbic regions is altered in adults with ASD, and provide a fresh perspective on the biology of ASD.

The impact of task load on the integration of explicit contextual priors and visual information during anticipation.

There is limited knowledge about the impact of task load on experts' integration of contextual priors and visual information during dynamic and rapidly evolving anticipation tasks. We examined how experts integrate contextual priors--specifically, prior information regarding an opponent's action tendencies--with visual information such as movement kinematics, during a soccer-specific anticipation task. Furthermore, we combined psychophysiological measures and retrospective self-reports to gain insight into the cognitive load associated with this integration. Players were required to predict the action of an oncoming opponent, with and without the explicit provision of contextual priors, under two different task loads. In addition to anticipation performance, we compared continuous electroencephalography (EEG) and self-reports of cognitive load across conditions. Our data provide tentative evidence that increased task load may impair performance by disrupting the integration of contextual priors and visual information. EEG data suggest that cognitive load may increase when contextual priors are explicitly provided, whereas self-report data suggested a decrease in cognitive load. The findings provide insight into the processing demands associated with integration of contextual priors and visual information during dynamic anticipation tasks, and have implications for the utility of priors under cognitively demanding conditions. Furthermore, our findings add to the existing literature, suggesting that continuous EEG may be a more valid measure than retrospective self-reports for in-task assessment of cognitive load.

Modulation of brain activation during executive functioning in autism with citalopram.

Adults with autism spectrum disorder (ASD) are frequently prescribed selective serotonin reuptake inhibitors (SSRIs). However, there is limited evidence to support this practice. Therefore, it is crucial to understand the impact of SSRIs on brain function abnormalities in ASD. It has been suggested that some core symptoms in ASD are underpinned by deficits in executive functioning (EF). Hence, we investigated the role of the SSRI citalopram on EF networks in 19 right-handed adult males with ASD and 19 controls who did not differ in gender, age, IQ or handedness. We performed pharmacological functional magnetic resonance imaging to compare brain activity during two EF tasks (of response inhibition and sustained attention) after an acute dose of 20 mg citalopram or placebo using a randomised, double-blind, crossover design. Under placebo condition, individuals with ASD had abnormal brain activation in response inhibition regions, including inferior frontal, precentral and postcentral cortices and cerebellum. During sustained attention, individuals with ASD had abnormal brain activation in middle temporal cortex and (pre)cuneus. After citalopram administration, abnormal brain activation in inferior frontal cortex was 'normalised' and most of the other brain functional differences were 'abolished'. Also, within ASD, the degree of responsivity in inferior frontal and postcentral cortices to SSRI challenge was related to plasma serotonin levels. These findings suggest that citalopram can 'normalise' atypical brain activation during EF in ASD. Future trials should investigate whether this shift in the biology of ASD is maintained after prolonged citalopram treatment, and if peripheral measures of serotonin predict treatment response.

Autism spectrum disorder: Consensus guidelines on assessment, treatment and research from the British Association for Psychopharmacology.

An expert review of the aetiology, assessment, and treatment of autism spectrum disorder, and recommendations for diagnosis, management and service provision was coordinated by the British Association for Psychopharmacology, and evidence graded. The aetiology of autism spectrum disorder involves genetic and environmental contributions, and implicates a number of brain systems, in particular the gamma-aminobutyric acid, serotonergic and glutamatergic systems. The presentation of autism spectrum disorder varies widely and co-occurring health problems (in particular epilepsy, sleep disorders, anxiety, depression, attention deficit/hyperactivity disorder and irritability) are common. We did not recommend the routine use of any pharmacological treatment for the core symptoms of autism spectrum disorder. In children, melatonin may be useful to treat sleep problems, dopamine blockers for irritability, and methylphenidate, atomoxetine and guanfacine for attention deficit/hyperactivity disorder. The evidence for use of medication in adults is limited and recommendations are largely based on extrapolations from studies in children and patients without autism spectrum disorder. We discuss the conditions for considering and evaluating a trial of medication treatment, when non-pharmacological interventions should be considered, and make recommendations on service delivery. Finally, we identify key gaps and limitations in the current evidence base and make recommendations for future research and the design of clinical trials.

Needs of Adolescents and Young Adults with Neurodevelopmental Disorders: Comparisons of Young People and Parent Perspectives.

This study used the Camberwell Assessment of Need for adults with Developmental and Intellectual Disabilities (CANDID) to examine the social, physical health and mental health needs of 168 young people (aged 14-24 years) with neurodevelopmental disorders and compared young person and parent ratings of need. Agreement was poor in 21 out of 25 domains. Parents consistently reported higher levels of need than young people in the majority of domains although young people with ADHD reported significantly more needs in physical health, eyesight/hearing, seizures, other mental health problems and safety of others than their parents. Both parent and young person perspectives of needs are necessary to ensure that needs that are predictive of current or future poor outcomes are not missed.

Clinical service use as people with Attention Deficit Hyperactivity Disorder transition into adolescence and adulthood: a prospective longitudinal study.

BACKGROUND: While Attention Deficit Hyperactivity Disorder (ADHD) often persists into adulthood, little is known about the needs and service use among adolescents and young adults with ADHD. The present study followed-up a cohort diagnosed with ADHD as children and assessed their: 1) needs, 2) correlates of contact with clinical services, and 3) experiences of transition from child to adult health services. METHODS: Ninety one young people aged 14-24 were recruited from the UK subset of the International Multi-Centre ADHD Genetics (IMAGE) Project. Affected young people and parents conducted face-to-face interviews and self-completion questionnaires including a modified version of the Client Services Receipt Inventory, The Barkley's ADHD rating scale, The Clinical Interview Schedule-Revised, and the Zarit Burden Interview. Changes in key need characteristics (e.g. ADHD symptoms and impairments) over a 3-year period were examined using fixed effect models. Generalised Estimating Equations (GEE) were used to explore how key characteristics (such as ADHD symptoms) were associated with contact with clinical services across the three years. RESULTS: At baseline 62 % met diagnostic criteria for ADHD and presented with a range of ADHD related impairments, psychiatric comorbidities, and significant caregiver burden. While ADHD symptoms and related impairments lessened significantly over the three years, psychiatric comorbidities and caregiver burden remained stable. The strongest correlate of contact with clinical services was age (OR 0.65 95 % CI 0.49-0.84) with the odds of reported contact with clinical services decreasing by 35 % for each year increase in age at baseline and by 25 % for each year increase in age over time. Only 9 % of the sample had experienced a transfer to adult services, with the majority reporting unmet needs in healthcare transition. CONCLUSIONS: Despite continuing needs, few were in contact with adult health services or had received sufficient help with transition between child and adult health services. The main determinant of health service use for adolescents and young adults with ADHD is age - not needs. Service models should address the needs of ADHD individuals who are no longer children.

Screening for co-occurring conditions in adults with autism spectrum disorder using the strengths and difficulties questionnaire: A pilot study.

Adolescents and adults with autism spectrum disorder (ASD) are at elevated risk of co-occurring mental health problems. These are often undiagnosed, can cause significant impairment, and place a very high burden on family and carers. Detecting co-occurring disorders is extremely important. However, there is no validated screening tool for this purpose. The aim of this pilot study is to test the utility of the strengths and difficulties questionnaire (SDQ) to screen for co-occurring emotional disorders and hyperactivity in adolescents and adults with ASD. The SDQ was completed by 126 parents and 98 individuals with ASD (in 79 cases both parent and self-report were available from the same families). Inter-rater reliability, test-retest stability, internal consistency, and construct validity were examined. SDQ subscales were also compared to clinically utilized measures of emotional disorders and hyperactivity to establish the ability to predict risk of disorder. Inter-rater reliability (r = 0.42), test-retest stability (r = 0.64), internal consistency (α = 0.52-0.81) and construct validity (r = 0.42-0.57) for the SDQ subscales were comparable to general population samples. Parent- and self-report SDQ subscales were significantly associated with measures of anxiety, depression and hyperactivity (62-74% correctly classified). Parent-report performed significantly better than self-report; adults with ASD under-reported difficulties. The SDQ shows promise as a simple and efficient way to screen for emotional disorders and hyperactivity in adolescents and adults with ASD that could help reduce the impact of these disorders on individuals and their families. However, further more systematic attempts at validation are warranted. Autism Res 2016, 9: 1353-1363. © 2016 International Society for Autism Research, Wiley Periodicals, Inc.

Obsessive-Compulsive Disorder in Adults with High-Functioning Autism Spectrum Disorder: What Does Self-Report with the OCI-R Tell Us?

Little is known about the symptom profile of obsessive-compulsive disorder (OCD) in individuals who have autism spectrum disorders (ASD). It is also unknown whether self-report questionnaires are useful in measuring OCD in ASD. We sought to describe the symptom profiles of adults with ASD, OCD, and ASD + OCD using the Obsessive Compulsive Inventory-Revised (OCI-R), and to assess the utility of the OCI-R as a screening measure in a high-functioning adult ASD sample. Individuals with ASD (n = 171), OCD (n = 108), ASD + OCD (n = 54) and control participants (n = 92) completed the OCI-R. Individuals with ASD + OCD reported significantly higher levels of obsessive-compulsive symptoms than those with ASD alone. OCD symptoms were not significantly correlated with core ASD repetitive behaviors as measured on the ADI-R or ADOS-G. The OCI-R showed good psychometric properties and corresponded well with clinician diagnosis of OCD. Receiver operating characteristic analysis suggested cut-offs for OCI-R Total and Checking scores that discriminated well between ASD + versus -OCD, and fairly well between ASD-alone and OCD-alone. OCD manifests separately from ASD and is characterized by a different profile of repetitive thoughts and behaviors. The OCI-R appears to be useful as a screening tool in the ASD adult population.

Caregiver burden as people with autism spectrum disorder and attention-deficit/hyperactivity disorder transition into adolescence and adulthood in the United Kingdom.

OBJECTIVE: There is increasing recognition that autism spectrum disorder (ASD) and attention-deficit/hyperactivity disorder (ADHD) are associated with significant costs and burdens. However, research on their impact has focused mostly on the caregivers of young children; few studies have examined caregiver burden as children transition into adolescence and young adulthood, and no one has compared the impact of ASD to other neurodevelopmental disorders (e.g., ADHD). METHOD: We conducted an observational study of 192 families caring for a young person (aged 14 to 24 years) with a childhood diagnosis of ASD or ADHD (n = 101 and n = 91, respectively) in the United Kingdom. A modified stress-appraisal model was used to investigate the correlates of caregiver burden as a function of family background (parental education), primary stressors (symptoms), primary appraisal (need), and resources (use of services). RESULTS: Both disorders were associated with a high level of caregiver burden, but it was significantly greater in ASD. In both groups, caregiver burden was mainly explained by the affected young person's unmet need. Domains of unmet need most associated with caregiver burden in both groups included depression/anxiety and inappropriate behavior. Specific to ASD were significant associations between burden and unmet needs in domains such as social relationships and major mental health problems. CONCLUSIONS: Adolescence and young adulthood are associated with high levels of caregiver burden in both disorders; in ASD, the level is comparable to that reported by persons caring for individuals with a brain injury. Interventions are required to reduce caregiver burden in this population.