Current psychiatric diagnoses, although heritable, have not been clearly mapped onto distinct underlying pathogenic processes. The same symptoms often occur in multiple disorders, and a substantial proportion of both genetic and environmental risk factors are shared across disorders. However, the relationship between shared symptoms and shared genetic liability is still poorly understood.

Well-characterised, cross-disorder samples are needed to investigate this matter, but few currently exist. Our aim is to develop procedures to purposely curate and aggregate genotypic and phenotypic data in psychiatric research.

As part of the Cardiff MRC Mental Health Data Pathfinder initiative, we have curated and harmonised phenotypic and genetic information from 15 studies to create a new data repository, DRAGON-Data. To date, DRAGON-Data includes over 45 000 individuals: adults and children with neurodevelopmental or psychiatric diagnoses, affected probands within collected families and individuals who carry a known neurodevelopmental risk copy number variant.

We have processed the available phenotype information to derive core variables that can be reliably analysed across groups. In addition, all data-sets with genotype information have undergone rigorous quality control, imputation, copy number variant calling and polygenic score generation.

DRAGON-Data combines genetic and non-genetic information, and is available as a resource for research across traditional psychiatric diagnostic categories. Algorithms and pipelines used for data harmonisation are currently publicly available for the scientific community, and an appropriate data-sharing protocol will be developed as part of ongoing projects (DATAMIND) in partnership with Health Data Research UK.

There is recent evidence of some degree of shared genetic susceptibility between adult schizophrenia and childhood attention-deficit hyperactivity disorder (ADHD) for rare chromosomal variants.

To determine whether there is overlap between common alleles conferring risk of schizophrenia in adults with those that do so for ADHD in children.

We used recently published Psychiatric Genome-wide Association Study (GWAS) Consortium (PGC) adult schizophrenia data to define alleles over-represented in people with schizophrenia and tested whether those alleles were more common in 727 children with ADHD than in 2067 controls.

Schizophrenia risk alleles discriminated ADHD cases from controls (P = 1.04 × 104, R2 = 0.45%); stronger discrimination was given by alleles that were risk alleles for both adult schizophrenia and adult bipolar disorder (also derived from a PGC data-set) (P = 9.98 ×10−6, R2 × 0.59%).

This increasing evidence for a small, but significant, shared genetic susceptibility between adult schizophrenia and childhood ADHD highlights the importance of research work across traditional diagnostic boundaries.

Submicroscopic, rare chromosomal copy number variants (CNVs) contribute to neurodevelopmental disorders but it is not known whether they define atypical clinical cases.

To identify whether large, rare CNVs in attention-deficit hyperactivity disorder (ADHD) are confined to a distinct clinical subgroup.

A total of 567 children with ADHD aged 5–17 years were recruited from community clinics. Psychopathology was assessed using the Child and Adolescent Psychiatric Assessment. Large, rare CNVs (>500 kb, <1% frequency) were defined from single nucleotide polymorphism data.

Copy number variant carriers (13.6%) showed no differences from non-carriers in ADHD symptom severity, symptom type, comorbidity, developmental features, family history or pre-/ perinatal markers. The only significant difference was a higher rate of intellectual disability (24% v. 9%, χ2 = 15.5, P = 0.001). Most CNV carriers did not have intellectual disability.

Large, rare CNVs are not restricted to an atypical form of ADHD but may be more highly enriched in children with cognitive problems.

Some research suggests that children with attention-deficit hyperactivity disorder (ADHD) have a higher than expected risk of bipolar affective disorder. No study has examined the prevalence of bipolar disorder in a UK sample of children with ADHD.

To examine the prevalence of bipolar disorder in children diagnosed with ADHD or hyperkinetic disorder.

Psychopathology symptoms and diagnoses of bipolar disorder were assessed in 200 young people with ADHD (170 male, 30 female; age 6–18 years, mean 11.15, s.d. = 2.95). Rates of current bipolar disorder symptoms and diagnoses are reported. A family history of bipolar disorder in parents and siblings was also recorded.

Only one child, a 9-year-old boy, met diagnostic criteria for both ICD–10 hypomania and DSM–IV bipolar disorder not otherwise specified.

In a UK sample of children with ADHD a current diagnosis of bipolar disorder was uncommon.

Attention-deficit hyperactivity disorder (ADHD) is recognised as a common, disabling condition. Little information is available regarding the long-term outcomes for individuals with ADHD in the UK.

To examine the 5-year outcome for a UK cohort of children with diagnosed, treated ADHD and identify whether maternal and social factors predict key outcomes.

One hundred and twenty-six school-aged children (mean age 9.4 years, s.d. = 1.7) diagnosed with ADHD were reassessed 5 years later during adolescence (mean age 14.5 years, s.d. = 1.7) for ADHD, conduct disorder and other antisocial behaviours.

Most adolescents (69.8%) continued to meet full criteria for ADHD, were known to specialist services and exhibited high levels of antisocial behaviour, criminal activity and substance use problems. Maternal childhood conduct disorder predicted offspring ADHD continuity; maternal childhood conduct disorder, lower child IQ and social class predicted offspring conduct disorder symptoms.

The treatment and monitoring of ADHD need to be intensified as outcomes are poor especially in offspring of mothers with childhood conduct disorder symptoms.

Children with attention-deficit hyperactivity disorder (ADHD) are thought to be at higher risk of psychopathy. Early biological and social adversity may contribute to this risk.

To examine psychopathy traits in ADHD.

In a sample of children with ADHD who had reached adolescence, total psychopathy and ‘emotional-dysfunction’ scores (e.g. callousness, lack of affect) were assessed using the Hare Psychopathy Checklist–Youth Version.

A total of 156 (79%) eligible families participated. Total psychopathy and emotional-dysfunction scores were elevated in comparison to published UK norms but none scored in the clinical range for psychopathy. Adjusting for associated conduct problems, total psychopathy scores were associated with maternal smoking during pregnancy, emotional-dysfunction scores were associated with birth complications, and neither was associated with family adversity.

Children with ADHD show psychopathy traits but are not ‘psychopaths’. Early adversity, indexed by pre- or perinatal adversity but not family factors, appears to be associated.

This study aimed to assess how referrers to specialist child and adolescent mental health services (CAMHS) wanted priorities to be determined. Postal questionnaires were sent to practitioners referring to the service in the Bridgend district.

Nearly three-quarters of the questionnaires were returned (n=184). There was wide variation between professional groups in the priority attributed to different presenting problems, their modification by ‘contextual factors' and acceptable waiting times for the service. Mental disorder, self-harm, child abuse and complex cases require greatest priority.

Needs of referrers must be considered when deciding priorities for specialist CAMHS, however diverse these appear. If youth mental health needs are to be addressed, better communication between services, and clearer definition of the role of specialist CAMHS is imperative.

The ICD – 10 and DSM – IV diagnostic criteria for hyperkinetic disorder and attention-deficit hyperactivity disorder (ADHD) require symptoms or impairment in two or more settings. Thus, information on children's symptoms in school is usually required. This paper presents the Child ADHD Teacher Telephone Interview (CHATTI), an instrument aimed at systematically obtaining this information.

To examine the stability, test–retest reliability and criterion validity of the CHATTI for children referred with a suspected diagnosis of ADHD.

Data were obtained from 79 teachers, of whom 36 were interviewed on two occasions.

Overall, the CHATTI shows good stability test–retest reliability and criterion validity for symptom scores. Test–retest reliability for some individual items was low. Reliability for the operationalised criteria of ‘pervasiveness' (i.e. symptoms at school and home) and ‘school impairment’ was excellent (κ=1).

The CHATTI appears to be a promising tool for assessing ADHD symptoms in a school setting and could be useful in clinical as well as research settings.