While it is well accepted that attention-deficit/hyperactivity disorder (ADHD) is a highly heritable disorder, not all of the risk is genetic. It is estimated that between 10 and 40% of the variance associated with ADHD is likely to be accounted for by environmental factors. There is considerable interest in the role that the prenatal environment might play in the development of ADHD with previous reviews concluding that despite demonstration of associations between prenatal risk factors (e.g. prematurity, maternal smoking during pregnancy) and ADHD, there remains insufficient evidence to support a definite causal relationship. This article provides an update of research investigating the relationship between prenatal risk factors and ADHD published over the past 3 years. Recently, several epidemiological and data linkage studies have made substantial contributions to our understanding of this relationship. In particular, these studies have started to account for some of the genetic and familial confounds that, when taken into account, throw several established findings into doubt. None of the proposed prenatal risk factors can be confirmed as causal for ADHD, and the stronger the study design, the less likely it is to support an association. We need a new benchmark for studies investigating the etiology of ADHD whereby there is an expectation not only that data will be collected prospectively but also that the design allows the broad range of genetic and familial factors to be accounted for.

These findings suggest that a brief behavioral sleep intervention can improve sleep problems in children with ADHD-ASD.

BackgroundWe aim to (1) determine whether a behavioural sleep intervention for children with attention-deficit/hyperactivity disorder (ADHD) leads to sustained benefits; and (2) examine the factors associated with treatment response.MethodsThis study was a randomised controlled trial of 244 children (5–13 years) with ADHD from Victoria, Australia. All participants had a moderate/severe sleep problem that met American Academy of Sleep Medicine criteria for an eligible sleep disorder by parent report. The two-session intervention covered sleep hygiene and standardised behavioural strategies. The control group received usual care. Parent- and teacher-reported outcomes at 12 months included sleep, ADHD severity, quality of life, daily functioning, behaviour, and parent mental health. Adjusted mixed effects regression analyses examined 12 month outcomes. Interaction analyses were used to determine moderators of intervention outcomes over time. The trial was registered with ISRCTN, http://www.controlled-trials.com (ISRCTN68819261).ResultsIntervention children were less likely to have a moderate/severe sleep problem by parent report at 12 months compared to usual care children (28.4% v. 46.5%, p = 0.03). Children in the intervention group fared better than the usual care group in terms of parent-reported ADHD symptoms (Cohen's d: −0.3, p < 0.001), quality of life (d: 0.4, p < 0.001), daily functioning (d: −0.5, p < 0.001), and behaviour (d: −0.3, p = 0.005) 12 months later. The benefits of the intervention over time in terms of sleep were less for children not taking ADHD medication and children with parents experiencing depression.ConclusionsA behavioural sleep intervention for ADHD is associated with small sustained improvements in child wellbeing. Children who are not taking ADHD medication or have parents with depression may require follow-up booster sleep sessions.

Irritable mood is implicated in a range of psychiatric conditions in both adults and adolescents. Research into appropriate measures of irritability, however, has been sparse. Recently, Stringaris et al. (2012) published the Affective Reactivity Index (ARI), a measure of chronic irritability with promising psychometric properties. This article presents psychometric properties of the ARI with Australian adolescents and, for the first time, with adults. The adolescent sample (n = 396) was recruited from 11 secondary schools in southeastern Australia. The adult sample (n = 221) was recruited through poster and online advertising. Both samples completed a battery of measures (including the ARI, Reynolds Adolescent Depression Scale-2, Strengths and Difficulties Questionnaire, Center for Epidemiologic Studies Depression Scale, Generalized Anxiety Disorder Screen, and Liebowitz Social Anxiety Scale) on a single occasion, and a subsample of adults (n = 32) completed the ARI a 2nd time after 1 week to establish test-retest reliability. Parent and self-report scales had excellent internal consistency and correlated well with each other. Test-retest reliability was also very good in the adult sample (intraclass correlation coefficient = .80). Convergent validity was demonstrated, as irritability was related to psychopathology in both adults and adolescents as expected. The ARI is a brief, easy-to-use scale to measure chronic irritability, with promising psychometric properties for use with Australian adults and adolescents.