GWAS have enjoyed substantial success in many areas, and are beginning to realise similar success for other phenotypes (e.g., psychiatric outcomes such as schizophrenia). Understanding the causal role of these phenotypes will be of considerable scientific and societal importance. The authors declare that there are no relevant conflicts of interest. Papers of particular interest, published within the period of review, have Selleckchem GSK-J4 been highlighted as: • of special interest The authors are members of the UK Centre for Tobacco and Alcohol Studies, a UKCRC Public Health Research: Centre of Excellence. Funding from British Heart Foundation, Cancer Research UK, Economic

and Social Research Council, Medical Research Council, and the National Institute for Health Research, under the auspices of the UK Clinical Research Collaboration, is gratefully acknowledged. This work was supported by the Medical Research Council (grant numbers MC_UU_12013/1 and MC_UU_12013/6).

JJW is supported by a Post-Doctoral Research Fellowship Bioactive Compound Library from the Oak Foundation. “
“Current Opinion in Behavioral Sciences 2015, 2:46–51 This review comes from a themed issue on Behavioral Genetics 2015 Edited by William Davies and Laramie Duncan http://dx.doi.org/10.1016/j.cobeha.2014.09.002 2352-1546/© 2014 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/3.0/). 3-mercaptopyruvate sulfurtransferase Attention-deficit/hyperactivity disorder (ADHD) is a neurodevelopmental disorder defined by inattention and/or hyperactivity-impulsivity that occurs in ∼5%

of children and ∼2.5% of adults worldwide [1]. Attention is the ability to focus on particular (important) sensory information and ignore other (less important) information. Attention can be divided into subdomains comprising alerting, orienting, and executive attention functions; and neuroimaging data in humans suggest the existence of broad attention networks [2•]. Impulse control is required to optimize animal actions, and is divided into subcognitive domains potentially involving distinct neuronal circuits and neurochemistry 3 and 4]. Imaging studies in ADHD indicate hypofunction and/or volume changes in various brain regions, such as the anterior cingulate, dorsolateral and inferior prefrontal cortices, basal ganglia, thalamus, parietal cortex, and cerebellum 4, 5 and 6]. Cognitive domains for attention and impulsivity may provide foundations of other cognitive/emotional domains and personality [7]. Inattentive and impulsive behaviors are also comorbid with other psychiatric disorders, such as autism spectrum disorders, bipolar disorder, and developmental coordination disorders 1, 8, 9 and 10]; and are a risk factor for the development of antisocial and drug-abuse disorders [1]. Family, adoption, and twin studies support the heritable etiology of ADHD (for review see: [11]).