In vivo evidence of microstructural hypo-connectivity of brain white matter in 22q11.2 deletion syndrome.

22q11.2 deletion syndrome, or 22q11.2DS, is a genetic syndrome associated with high rates of schizophrenia and autism spectrum disorders, in addition to widespread structural and functional abnormalities throughout the brain. Experimental animal models have identified neuronal connectivity deficits, e.g., decreased axonal length and complexity of axonal branching, as a primary mechanism underlying atypical brain development in 22q11.2DS. However, it is still unclear whether deficits in axonal morphology can also be observed in people with 22q11.2DS. Here, we provide an unparalleled in vivo characterization of white matter microstructure in participants with 22q11.2DS (12-15 years) and those undergoing typical development (8-18 years) using a customized magnetic resonance imaging scanner which is sensitive to axonal morphology. A rich array of diffusion MRI metrics are extracted to present microstructural profiles of typical and atypical white matter development, and provide new evidence of connectivity differences in individuals with 22q11.2DS. A recent, large-scale consortium study of 22q11.2DS identified higher diffusion anisotropy and reduced overall diffusion mobility of water as hallmark microstructural alterations of white matter in individuals across a wide age range (6-52 years). We observed similar findings across the white matter tracts included in this study, in addition to identifying deficits in axonal morphology. This, in combination with reduced tract volume measurements, supports the hypothesis that abnormal microstructural connectivity in 22q11.2DS may be mediated by densely packed axons with disproportionately small diameters. Our findings provide insight into the in vivo white matter phenotype of 22q11.2DS, and promote the continued investigation of shared features in neurodevelopmental and psychiatric disorders.

Brain functional connectivity mirrors genetic pleiotropy in psychiatric conditions.

Pleiotropy occurs when a genetic variant influences more than one trait. This is a key property of the genomic architecture of psychiatric disorders and has been observed for rare and common genomic variants. It is reasonable to hypothesize that the microscale genetic overlap (pleiotropy) across psychiatric conditions and cognitive traits may lead to similar overlaps at the macroscale brain level such as large-scale brain functional networks. We took advantage of brain connectivity, measured by resting-state functional MRI to measure the effects of pleiotropy on large-scale brain networks, a putative step from genes to behaviour. We processed nine resting-state functional MRI datasets including 32 726 individuals and computed connectome-wide profiles of seven neuropsychiatric copy-number-variants, five polygenic scores, neuroticism and fluid intelligence as well as four idiopathic psychiatric conditions. Nine out of 19 pairs of conditions and traits showed significant functional connectivity correlations (rFunctional connectivity), which could be explained by previously published levels of genomic (rGenetic) and transcriptomic (rTranscriptomic) correlations with moderate to high concordance: rGenetic-rFunctional connectivity = 0.71 [0.40-0.87] and rTranscriptomic-rFunctional connectivity = 0.83 [0.52; 0.94]. Extending this analysis to functional connectivity profiles associated with rare and common genetic risk showed that 30 out of 136 pairs of connectivity profiles were correlated above chance. These similarities between genetic risks and psychiatric disorders at the connectivity level were mainly driven by the overconnectivity of the thalamus and the somatomotor networks. Our findings suggest a substantial genetic component for shared connectivity profiles across conditions and traits, opening avenues to delineate general mechanisms-amenable to intervention-across psychiatric conditions and genetic risks.

Psychopathology in mothers of children with pathogenic Copy Number Variants.

BACKGROUND: Caring for children with pathogenic neurodevelopmental Copy Number Variants (CNVs) (ie, deletions and duplications of genetic material) can place a considerable burden on parents and their quality of life. Our study is the first to examine the frequency of psychiatric diagnoses in mothers of children with CNVs compared with the frequency of psychiatric problems in age-matched mothers from a large community study. METHODS: Case-control study. 268 mothers of children with a CNV diagnosed in a medical genetics clinic and 2680 age-matched mothers taking part in the Avon Longitudinal Study of Parents and Children study. RESULTS: Mothers of children with CNVs reported higher frequency of depression, anorexia, bulimia, alcohol abuse and drug addiction problems compared with the age-matched mothers from the community sample. Focusing on psychiatric problems arising immediately after the birth of the index child, we found that the levels of depression symptoms were similar between the two groups (48% in mothers of children with CNVs vs 44% in mothers of the community sample, p=0.43), but mothers of children with CNVs had higher frequency of anxiety symptoms (55%) compared with mothers from the community sample (30%, p=0.03). CONCLUSION: Our study highlights the need for healthcare providers to devise treatment plans that not only focus on meeting the child's needs but also assess and, if needed, address the mental health needs of the parent.

Psychopathology in adults with copy number variants.

BACKGROUND: Copy number variants (CNVs) have been associated with the risk of schizophrenia, autism and intellectual disability. However, little is known about their spectrum of psychopathology in adulthood. METHODS: We investigated the psychiatric phenotypes of adult CNV carriers and compared probands, who were ascertained through clinical genetics services, with carriers who were not. One hundred twenty-four adult participants (age 18-76), each bearing one of 15 rare CNVs, were recruited through a variety of sources including clinical genetics services, charities for carriers of genetic variants, and online advertising. A battery of psychiatric assessments was used to determine psychopathology. RESULTS: The frequencies of psychopathology were consistently higher for the CNV group compared to general population rates. We found particularly high rates of neurodevelopmental disorders (NDDs) (48%), mood disorders (42%), anxiety disorders (47%) and personality disorders (73%) as well as high rates of psychiatric multimorbidity (median number of diagnoses: 2 in non-probands, 3 in probands). NDDs [odds ratio (OR) = 4.67, 95% confidence interval (CI) 1.32-16.51; p = 0.017) and psychotic disorders (OR = 6.8, 95% CI 1.3-36.3; p = 0.025) occurred significantly more frequently in probands (N = 45; NDD: 39[87%]; psychosis: 8[18%]) than non-probands (N = 79; NDD: 20 [25%]; psychosis: 3[4%]). Participants also had somatic diagnoses pertaining to all organ systems, particularly conotruncal cardiac malformations (in individuals with 22q11.2 deletion syndrome specifically), musculoskeletal, immunological, and endocrine diseases. CONCLUSIONS: Adult CNV carriers had a markedly increased rate of anxiety and personality disorders not previously reported and high rates of psychiatric multimorbidity. Our findings support in-depth psychiatric and medical assessments of carriers of CNVs and the establishment of multidisciplinary clinical services.

Using induced pluripotent stem cells to investigate human neuronal phenotypes in 1q21.1 deletion and duplication syndrome.

Copy Number Variation (CNV) at the 1q21.1 locus is associated with a range of neurodevelopmental and psychiatric disorders in humans, including abnormalities in head size and motor deficits. Yet, the functional consequences of these CNVs (both deletion and duplication) on neuronal development remain unknown. To determine the impact of CNV at the 1q21.1 locus on neuronal development, we generated induced pluripotent stem cells from individuals harbouring 1q21.1 deletion or duplication and differentiated them into functional cortical neurons. We show that neurons with 1q21.1 deletion or duplication display reciprocal phenotype with respect to proliferation, differentiation potential, neuronal maturation, synaptic density and functional activity. Deletion of the 1q21.1 locus was also associated with an increased expression of lower cortical layer markers. This difference was conserved in the mouse model of 1q21.1 deletion, which displayed altered corticogenesis. Importantly, we show that neurons with 1q21.1 deletion and duplication are associated with differential expression of calcium channels and demonstrate that physiological deficits in neurons with 1q21.1 deletion or duplication can be pharmacologically modulated by targeting Ca2+ channel activity. These findings provide biological insight into the neuropathological mechanism underlying 1q21.1 associated brain disorder and indicate a potential target for therapeutic interventions.

Assessment of emotions and behaviour by the Developmental Behaviour Checklist in young people with neurodevelopmental CNVs.

BACKGROUND: A number of genomic conditions caused by copy number variants (CNVs) are associated with a high risk of neurodevelopmental and psychiatric disorders (ND-CNVs). Although these patients also tend to have cognitive impairments, few studies have investigated the range of emotion and behaviour problems in young people with ND-CNVs using measures that are suitable for those with learning difficulties. METHODS: A total of 322 young people with 13 ND-CNVs across eight loci (mean age: 9.79 years, range: 6.02-17.91, 66.5% male) took part in the study. Primary carers completed the Developmental Behaviour Checklist (DBC). RESULTS: Of the total, 69% of individuals with an ND-CNV screened positive for clinically significant difficulties. Young people from families with higher incomes (OR = 0.71, CI = 0.55-0.91, p = .008) were less likely to screen positive. The rate of difficulties differed depending on ND-CNV genotype (χ2 = 39.99, p < 0.001), with the lowest rate in young people with 22q11.2 deletion (45.7%) and the highest in those with 1q21.1 deletion (93.8%). Specific patterns of strengths and weaknesses were found for different ND-CNV genotypes. However, ND-CNV genotype explained no more than 9-16% of the variance, depending on DBC subdomain. CONCLUSIONS: Emotion and behaviour problems are common in young people with ND-CNVs. The ND-CNV specific patterns we find can provide a basis for more tailored support. More research is needed to better understand the variation in emotion and behaviour problems not accounted for by genotype.

Coordination difficulties, IQ and psychopathology in children with high-risk copy number variants.

BACKGROUND: The prevalence and impact of motor coordination difficulties in children with copy number variants associated with neurodevelopmental disorders (ND-CNVs) remains unknown. This study aims to advance understanding of motor coordination difficulties in children with ND-CNVs and establish relationships between intelligence quotient (IQ) and psychopathology. METHODS: 169 children with an ND-CNV (67% male, median age = 8.88 years, range 6.02-14.81) and 72 closest-in-age unaffected siblings (controls; 55% male, median age = 10.41 years, s.d. = 3.04, range 5.89-14.75) were assessed with the Developmental Coordination Disorder Questionnaire, alongside psychiatric interviews and standardised assessments of IQ. RESULTS: The children with ND-CNVs had poorer coordination ability (b = 28.98, p < 0.001) and 91% of children with an ND-CNV screened positive for suspected developmental coordination disorder, compared to 19% of controls (OR = 42.53, p < 0.001). There was no difference in coordination ability between ND-CNV genotypes (F = 1.47, p = 0.184). Poorer coordination in children with ND-CNV was associated with more attention deficit hyperactivity disorder (ADHD) (ß = -0.18, p = 0.021) and autism spectrum disorder trait (ß = -0.46, p < 0.001) symptoms, along with lower full-scale (ß = 0.21, p = 0.011), performance (ß = -0.20, p = 0.015) and verbal IQ (ß = 0.17, p = 0.036). Mediation analysis indicated that coordination ability was a full mediator of anxiety symptoms (69% mediated, p = 0.012), and a partial mediator of ADHD (51%, p = 0.001) and autism spectrum disorder trait symptoms (66%, p < 0.001) as well as full scale IQ (40%, p = 0.002), performance IQ (40%, p = 0.005) and verbal IQ (38%, p = 0.006) scores. CONCLUSIONS: The findings indicate that poor motor coordination is highly prevalent and closely linked to risk of mental health disorder and lower intellectual function in children with ND-CNVs. Future research should explore whether early interventions for poor coordination ability could ameliorate neurodevelopmental risk.

Large-scale mapping of cortical alterations in 22q11.2 deletion syndrome: Convergence with idiopathic psychosis and effects of deletion size.

The 22q11.2 deletion (22q11DS) is a common chromosomal microdeletion and a potent risk factor for psychotic illness. Prior studies reported widespread cortical changes in 22q11DS, but were generally underpowered to characterize neuroanatomic abnormalities associated with psychosis in 22q11DS, and/or neuroanatomic effects of variability in deletion size. To address these issues, we developed the ENIGMA (Enhancing Neuro Imaging Genetics Through Meta-Analysis) 22q11.2 Working Group, representing the largest analysis of brain structural alterations in 22q11DS to date. The imaging data were collected from 10 centers worldwide, including 474 subjects with 22q11DS (age = 18.2 ± 8.6; 46.9% female) and 315 typically developing, matched controls (age = 18.0 ± 9.2; 45.9% female). Compared to controls, 22q11DS individuals showed thicker cortical gray matter overall (left/right hemispheres: Cohen's d = 0.61/0.65), but focal thickness reduction in temporal and cingulate cortex. Cortical surface area (SA), however, showed pervasive reductions in 22q11DS (left/right hemispheres: d = -1.01/-1.02). 22q11DS cases vs. controls were classified with 93.8% accuracy based on these neuroanatomic patterns. Comparison of 22q11DS-psychosis to idiopathic schizophrenia (ENIGMA-Schizophrenia Working Group) revealed significant convergence of affected brain regions, particularly in fronto-temporal cortex. Finally, cortical SA was significantly greater in 22q11DS cases with smaller 1.5 Mb deletions, relative to those with typical 3 Mb deletions. We found a robust neuroanatomic signature of 22q11DS, and the first evidence that deletion size impacts brain structure. Psychotic illness in this highly penetrant deletion was associated with similar neuroanatomic abnormalities to idiopathic schizophrenia. These consistent cross-site findings highlight the homogeneity of this single genetic etiology, and support the suitability of 22q11DS as a biological model of schizophrenia.

Autism spectrum disorder diagnosis in adults: phenotype and genotype findings from a clinically derived cohort.

BACKGROUND: The past decade has seen the development of services for adults presenting with symptoms of autism spectrum disorder (ASD) in the UK. Compared with children, little is known about the phenotypic and genetic characteristics of these patients. AIMS: This e-cohort study aimed to examine the phenotypic and genetic characteristics of a clinically presenting sample of adults diagnosed with ASD by specialist services. METHOD: Individuals diagnosed with ASD as adults were recruited by the National Centre for Mental Health and completed self-report questionnaires, interviews and provided DNA; 105 eligible individuals were matched to 76 healthy controls. We investigated demographics, social history and comorbid psychiatric and physical disorders. Samples were genotyped, copy number variants (CNVs) were called and polygenic risk scores were calculated. RESULTS: Of individuals with ASD, 89.5% had at least one comorbid psychiatric diagnosis, with depression (62.9%) and anxiety (55.2%) being the most common. The ASD group experienced more neurological comorbidities than controls, particularly migraine headache. They were less likely to have married or be in work, and had more alcohol-related problems. There was a significantly higher load of autism common genetic variants in the adult ASD group compared with controls, but there was no difference in the rate of rare CNVs. CONCLUSIONS: This study provides important information about psychiatric comorbidity in adult ASD, which may inform clinical practice and patient counselling. It also suggests that the polygenic load of common ASD-associated variants may be important in conferring risk within the non-intellectually disabled population of adults with ASD. DECLARATION OF INTEREST: None.

Epilepsy and seizures in young people with 22q11.2 deletion syndrome: Prevalence and links with other neurodevelopmental disorders.

OBJECTIVE: The true prevalence of epileptic seizures and epilepsy in 22q11.2 deletion syndrome (22q11.2DS) is unknown, because previous studies have relied on historical medical record review. Associations of epilepsy with other neurodevelopmental manifestations (eg, specific psychiatric diagnoses) remain unexplored. METHODS: The primary caregivers of 108 deletion carriers (mean age 13.6 years) and 60 control siblings (mean age 13.1 years) completed a validated epilepsy screening questionnaire. A subsample (n = 44) underwent a second assessment with interview, prolonged electroencephalography (EEG), and medical record and epileptologist review. Intelligence quotient (IQ), psychopathology, and other neurodevelopmental problems were examined using neurocognitive assessment and questionnaire/interview. RESULTS: Eleven percent (12/108) of deletion carriers had an epilepsy diagnosis (controls 0%, P = 0.004). Fifty-seven of the remaining 96 deletion carriers (59.4%) had seizures or seizurelike symptoms (controls 13.3%, 8/60, P < 0.001). A febrile seizure was reported for 24.1% (26/107) of cases (controls 0%, P < 0.001). One deletion carrier with a clinical history of epilepsy was diagnosed with an additional type of unprovoked seizure during the second assessment. One deletion carrier was newly diagnosed with epilepsy, and two more with possible nonmotor absence seizures. A positive screen on the epilepsy questionnaire was more likely in deletion carriers with lower performance IQ (odds ratio [OR] 0.96, P = 0.018), attention-deficit/hyperactivity disorder (ADHD) (OR 3.28, P = 0.021), autism symptoms (OR 3.86, P = 0.004), and indicative motor coordination disorder (OR 4.56, P = 0.021). SIGNIFICANCE: Even when accounting for deletion carriers diagnosed with epilepsy, reports of seizures and seizurelike symptoms are common. These may be "true" epileptic seizures in some cases, which are not recognized during routine clinical care. Febrile seizures were far more common in deletion carriers compared to known population risk. A propensity for seizures in 22q11.2DS was associated with cognitive impairment, psychopathology, and motor coordination problems. Future research is required to determine whether this reflects common neurobiologic risk pathways or is a consequence of recurrent seizures.

Developmental coordination disorder, psychopathology and IQ in 22q11.2 deletion syndrome.

BACKGROUND: 22q11.2 deletion syndrome (22q11.2DS) is associated with high rates of neurodevelopmental disorder, however, the links between developmental coordination disorder (DCD), intellectual function and psychiatric disorder remain unexplored. Aims To establish the prevalence of indicative DCD in children with 22q11.2DS and examine associations with IQ, neurocognition and psychopathology. METHOD: Neurocognitive assessments and psychiatric interviews of 70 children with 22q11.2DS (mean age 11.2, s.d. = 2.2) and 32 control siblings (mean age 11.5, s.d. = 2.1) were carried out in their homes. Nine children with 22q11.2DS and indicative DCD were subsequently assessed in an occupational therapy clinic. RESULTS: Indicative DCD was found in 57 (81.4%) children with 22q11.2DS compared with 2 (6.3%) control siblings (odds ratio (OR) = 36.7, P < 0.001). Eight of nine (89%) children with indicative DCD met DSM-5 criteria for DCD. Poorer coordination was associated with increased numbers of anxiety, (P < 0.001), attention-deficit hyperactivity disorder (ADHD) (P < 0.001) and autism-spectrum disorder (ASD) symptoms (P < 0.001) in children with 22q11.2DS. Furthermore, 100% of children with 22q11.2DS and ADHD had indicative DCD (20 of 20), as did 90% of children with anxiety disorder (17 of 19) and 96% of children who screened positive for ASD (22 of 23). The Developmental Coordination Disorder Questionnaire score was related to sustained attention (P = 0.006), even after history of epileptic fits (P = 0.006) and heart problems (P = 0.009) was taken into account. CONCLUSIONS: Clinicians should be aware of the high risk of coordination difficulties in children with 22q11.2DS and its association with risk of mental disorder and specific neurocognitive deficits. Declaration of interest None.

Childhood cognitive development in 22q11.2 deletion syndrome: case-control study.

Background22q11.2 deletion syndrome (22q11.2DS) is associated with a high risk of childhood as well as adult psychiatric disorders, in particular schizophrenia. Childhood cognitive deterioration in 22q11.2DS has previously been reported, but only in studies lacking a control sample.AimsTo compare cognitive trajectories in children with 22q11.2DS and unaffected control siblings.MethodA longitudinal study of neurocognitive functioning (IQ, executive function, processing speed and attention) was conducted in children with 22q11.2DS (n = 75, mean age time 1 (T1) 9.9, time 2 (T2) 12.5) and control siblings (n = 33, mean age T1 10.6, T2 13.4).ResultsChildren with 22q11.2DS exhibited deficits in all cognitive domains. However, mean scores did not indicate deterioration. When individual trajectories were examined, some participants showed significant decline over time, but the prevalence was similar for 22q11.2DS and control siblings. Findings are more likely to reflect normal developmental fluctuation than a 22q11.2DS-specific abnormality.ConclusionsChildhood cognitive deterioration is not associated with 22q11.2DS. Contrary to previous suggestions, we believe it is premature to recommend repeated monitoring of cognitive function for identifying individual children with 22q11.2DS at high risk of developing schizophrenia.

Psychopathology among young homeless people: longitudinal mental health outcomes for different subgroups.

BACKGROUND: Homeless young people are recognized as a very vulnerable group in terms of mental health; however, few studies in the UK have examined this. Furthermore, homeless young people represent a heterogeneous group in terms of their mental health and greater characterization could improve intervention work. OBJECTIVES: The aims of this study were to examine prevalence and subtypes of psychopathology among a British sample of young homeless people and to investigate potential associations between identified typologies and a priori specified current and past experiences. In addition, the study intended to explore physical health, mental health, and housing outcomes for the different mental health subgroups. DESIGN: A prospective longitudinal design was used. METHODS: Structured interviews including a mental health assessment were conducted with 90 young homeless people aged 16-23 years. Follow-up interviews were conducted approximately 10 and 20 months later. Cluster analysis at baseline was used to identify groups based on lifetime mental health problems. RESULTS: The current and lifetime incidence of mental health problems was high (88% and 93%, respectively). Three subgroups of homeless young people were identified: (1) minimal mental health issues; (2) mood, substance, and conduct disorder; and (3) post-traumatic stress disorder, mood, and anxiety issues. These groups differed with respect to follow-up indicators of change and stability of mental health status, service use, and suicide risk, but not housing outcome. Other characteristics (gender ratio, past experiences) also distinguished the subgroups. CONCLUSIONS: Typologies of young homeless people based on psychopathology reveal differences in lifetime and future experiences including mental health at follow-up. Identified groups could be used to tailor interventions towards differing needs. PRACTITIONER POINTS: Low mood, anxiety, post-traumatic stress disorder, and psychosis are common mental health issues among young homeless people in the UK. Subgroups of young homeless people with differing needs can be identified, and these groups can be used to predict outcomes. Tailoring support provision towards specific needs has the potential to improve mental health and other outcomes for vulnerable young homeless people. Young homeless people often do not access the support to which they are entitled. Services need to be adapted to improve access for this group.

The Developmental Relationship Between Depressive Symptoms in Adolescence and Harmful Drinking in Emerging Adulthood: The Role of Peers and Parents.

Depressive symptoms have been linked to the development of harmful drinking in adolescence but it remains unclear to what extent this effect continues into emerging adulthood. Deviant peers represent a risk factor while parental monitoring is a protective factor for harmful drinking. The study explored the relationship between depressive symptoms and harmful drinking between early adolescence and emerging adulthood. We also assessed to what extent this relationship is mediated by the influence of deviant peers and whether parental monitoring weakens this process. The sample consisted of 2964 adolescents (64 % females) from the Avon Longitudinal Study of Parents and Children study assessed between the ages of 14 and 19. Using structural equation modelling, we found that affiliation with deviant peers mediated the association between depressive symptoms and harmful drinking after adjustment for socio-demographic variables, parental drinking and depression, teenager's sex, conduct problems as well as drinking and depressive symptoms in early adolescence. We also found that parental control and solicitation reduced the influence of deviant peers on harmful drinking. The results indicate that prevention programs should offer adolescents training for peer resistance training and monitoring skills training for parents may have a long-term effect at weakening peer influences on harmful drinking.

The clinical presentation of attention deficit-hyperactivity disorder (ADHD) in children with 22q11.2 deletion syndrome.

BACKGROUND: Although attention deficit-hyperactivity disorder (ADHD) is the most prevalent psychiatric disorder in children with 22q11.2DS, it remains unclear whether its clinical presentation is similar to that in children with idiopathic ADHD. The aim of this study is to compare the ADHD phenotype in children with and without 22q11.2DS by examining ADHD symptom scores, patterns of psychiatric comorbidity, IQ and gender distribution. METHODS: Forty-four children with 22q11.2DS and ADHD (mean age = 9.6), 600 clinic children (mean age = 10.8) and 77 children with ADHD from a population cohort (mean age = 10.8) participated in the study. Psychopathology was assessed using parent-report research diagnostic instruments. RESULTS: There was a higher proportion of females in the 22q11.2DS ADHD sample in relation to the clinical sample (χ(2) = 18.2, P < 0.001). The 22q11.2DS group showed a higher rate of ADHD inattentive subtype (χ(2) = 114.76, P < 0.001), and fewer hyperactive-impulsive symptoms compared to the clinical group (z = 8.43, P < 0.001). The 22q11.2DS ADHD group parents reported fewer oppositional defiant disorder/conduct disorder symptoms (z = 6.33, P < 0.001) and a higher rate of generalized anxiety disorder (χ(2) = 4.56, P = 0.03) in relation to the clinical group. Two percent of the 22q11.2 DS ADHD sample had received ADHD treatment. The results were similar when the 22q11.2 ADHD group was compared to the population cohort ADHD group. CONCLUSIONS: The clinical presentation of ADHD and patterns of co-morbidity in 22q11.2DS is different from that in idiopathic ADHD. This could lead to clinical under-recognition of ADHD in this group. Examining psychopathology in 22q11.2DS can provide insights into the genetic origins of psychiatric problems with implications beyond the 22q11.2DS population.

Psychopathology and cognition in children with 22q11.2 deletion syndrome.

BACKGROUND: Children with 22q11.2 deletion syndrome (22q11.2DS) have been reported to have high rates of cognitive and psychiatric problems. AIMS: To establish the nature and prevalence of psychiatric disorder and neurocognitive impairment in children with 22q11.2DS and test whether risk of psychopathology is mediated by the children's intellectual impairment. METHOD: Neurocognition and psychopathology were assessed in 80 children with 22q11.2DS (mean age 10.2 years, s.d. = 2.1) and 39 sibling controls (mean age 10.9 years, s.d. = 2.0). RESULTS: More than half (54%) of children with 22q11.2DS met diagnostic criteria for one or more DSM-IV-TR psychiatric disorder. These children had lower IQ (mean 76.8, s.d. = 13.0) than controls (mean 108.6, s.d. = 15.2) (P<0.001) and showed a range of neurocognitive impairments. Increased risk of psychopathology was not mediated by intellectual impairment. CONCLUSIONS: 22q11.2DS is not related to a specific psychiatric phenotype in children. Moreover, the deletion has largely independent effects on IQ and risk of psychopathology, indicating that psychopathology in 22q11.2DS is not a non-specific consequence of generalised cognitive impairment.

Exploring the indirect effects of catechol-O-methyltransferase (COMT) genotype on psychotic experiences through cognitive function and anxiety disorders in a large birth cohort of children.

Children reporting psychotic experiences (PEs) are at increased risk of developing psychosis in adulthood. Cognitive deficits and anxiety disorders often precede psychotic disorders and are associated with higher risk of PEs. While the high activity alleles of variants within COMT have been associated with cognitive deficits, and the low activity alleles with higher risk of anxiety disorders, no associations of COMT with PEs have been found. One possible explanation is that the association between COMT and PEs is indirect, through cognitive function and anxiety disorders. We examined whether the association between PEs and COMT (four single nucleotide polymorphisms and three haplotypes) is indirect, through cognition or anxiety disorders. 6,784 individuals from the Avon Longitudinal Study of Parents and Children (ALSPAC) were genotyped and completed neurocognitive assessments at ages 8 and 11, as well as semi-structured interviews for anxiety disorders and PEs at ages 10 and 12, respectively. Alleles rs2097603 and rs4680, and two COMT haplotypes, all indexing high activity, were indirectly associated with higher risk of PEs through impaired processing speed, IQ and attention. There was no evidence of a total effect of COMT on PEs, nor for an indirect effect through anxiety disorders. This is the first study to examine indirect effects of COMT on PEs. Evidence of an indirect association suggests a complex developmental pathway underlies the emergence of PEs in children, with possible implications for prevention/intervention strategies. Our findings provide additional support for processing speed and attention as endophenotypes in psychotic disorders.

Irritability in young people with copy number variants associated with neurodevelopmental disorders (ND-CNVs).

A range of rare mutations involving micro-deletion or -duplication of genetic material (copy number variants (CNVs)) have been associated with high neurodevelopmental and psychiatric risk (ND-CNVs). Irritability is frequently observed in childhood neurodevelopmental conditions, yet its aetiology is largely unknown. Genetic variation may play a role, but there is a sparsity of studies investigating the presentation of irritability in young people with ND-CNVs. This study aimed to investigate whether there is a difference in irritability in young people with rare ND-CNVs compared to those without ND-CNVs, and to what extent irritability is associated with psychiatric diagnoses and cognitive ability (IQ). Irritability and broader psychopathology were assessed in 485 young people with ND-CNVs and 164 sibling controls, using the child and adolescent psychiatric assessment. Autism was assessed using the social communication questionnaire, and intelligence quotient (IQ) by the Wechsler abbreviated scale of intelligence. Fifty four percent of young people with ND-CNVs met the threshold for irritability; significantly more than controls (OR = 3.77, CI = 3.07-7.90, p = 5.31 × 10-11). When controlling for the presence of other psychiatric comorbidities, ND-CNV status was still associated with irritability. There was no evidence for a relationship between irritability and IQ. Irritability is an important aspect of the clinical picture in young people with ND-CNVs. This work shows that genetic variation is associated with irritability in young people with ND-CNVs, independent of psychiatric comorbidities or IQ impairment. Clinicians should be aware of this increased risk to inform management and interventions.