This is the submitted version of a work that was accepted for publication in: The Lancet Psychiatry. A definitive version was subsequently published in The Lancet Psychiatry 2.11 (2015), DOI: 10.1016/S2215-0366(15)00332-6Mental and brain disorders represent the greatest health burden to Europe—not only for directly affected individuals, but also for their caregivers and the wider society. They incur substantial economic costs through direct (and indirect) health-care and welfare spending, and via productivity losses, all of which substantially affect European development. Funding for research to mitigate these effects lags far behind the cost of mental and brain disorders to society. Here, we describe a comprehensive, coordinated mental health research agenda for Europe and worldwide. This agenda was based on systematic reviews of published work and consensus decision making by multidisciplinary scientific experts and affected stakeholders (more than 1000 in total): individuals with mental health problems and their families, health-care workers, policy makers, and funders. We generated six priorities that will, over the next 5–10 years, help to close the biggest gaps in mental health research in Europe, and in turn overcome the substantial challenges caused by mental disordersThe research leading to these results has received funding from the European Commission’s Seventh Framework Programme (FP7, 2007–13) under grant agreement number 282586, and from the National R&D Internationalisation Programme of the Spanish Ministry of Science and Technology under Reference ACI-PRO-2011- 1080. TW and GT acknowledge financial support from the UK National Institute for Health Research (NIHR) Biomedical Research Centre and Dementia Unit awarded to South London and Maudsley National Health Service (NHS) Foundation Trust in partnership with King’s College London. GT is supported by the NIHR Collaboration for Leadership in Applied Health Research and Care South London at King’s College London Foundation Trust. TW is supported by an NIHR Senior Investigator Award

There is recognition that biomedical research into the causes of mental disorders and their treatment needs to adopt new approaches to research. Novel biomedical techniques have advanced our understanding of how the brain develops and is shaped by behaviour and environment. This has led to the advent of stratified medicine, which translates advances in basic research by targeting aetiological mechanisms underlying mental disorder. The resulting increase in diagnostic precision and targeted treatments may provide a window of opportunity to address the large public health burden, and individual suffering associated with mental disorders. While mental health and mental disorders have significant representation in the "health, demographic change and wellbeing" challenge identified in Horizon 2020, the framework programme for research and innovation of the European Commission (2014-2020), and in national funding agencies, clear advice on a potential strategy for mental health research investment is needed. The development of such a strategy is supported by the EC-funded "Roadmap for Mental Health Research" (ROAMER) which will provide recommendations for a European mental health research strategy integrating the areas of biomedicine, psychology, public health well being, research integration and structuring, and stakeholder participation. Leading experts on biomedical research on mental disorders have provided an assessment of the state of the art in core psychopathological domains, including arousal and stress regulation, affect, cognition social processes, comorbidity and pharmacotherapy. They have identified major advances and promising methods and pointed out gaps to be addressed in order to achieve the promise of a stratified medicine for mental disorders.

Despite the high impact of mental disorders in society, European mental health research is at a critical situation with a relatively low level of funding, and few advances been achieved during the last decade. The development of coordinated research policies and integrated research networks in mental health is lagging behind other disciplines in Europe, resulting in lower degree of cooperation and scientific impact.To reduce more efficiently the burden of mental disorders in Europe, a concerted new research agenda is necessary. The ROAMER (Roadmap for Mental Health Research in Europe) project, funded under the European Commission's Seventh Framework Programme, aims to develop a comprehensive and integrated mental health research agenda within the perspective of the European Union (EU) Horizon 2020 programme, with a translational goal, covering basic, clinical and public health research.ROAMER covers six major domains: infrastructures and capacity building, biomedicine, psychological research and treatments, social and economic issues, public health and well-being. Within each of them, state-of-the-art and strength, weakness and gap analyses were conducted before building consensus on future research priorities. The process is inclusive and participatory, incorporating a wide diversity of European expert researchers as well as the views of service users, carers, professionals and policy and funding institutions.

Impulsivity is associated with a spectrum of psychiatric disorders including drug addiction. To investigate genetic associations with impulsivity and initiation of drug taking, we took a two-step approach. First, we identified genes whose expression level in prefrontal cortex, striatum and accumbens were associated with impulsive behavior in the 5-choice serial reaction time task across 10 BXD recombinant inbred (BXD RI) mouse strains and their progenitor C57BL/6J and DBA2/J strains. Behavioral data were correlated with regional gene expression using GeneNetwork (www.genenetwork.org), to identify 44 genes whose probability of association with impulsivity exceeded a false discovery rate of < 0.05. We then interrogated the IMAGEN database of 1423 adolescents for potential associations of SNPs in human homologs of those genes identified in the mouse study, with brain activation during impulsive performance in the Monetary Incentive Delay task, and with novelty seeking scores from the Temperament and Character Inventory, as well as alcohol experience. There was a significant overall association between the human homologs of impulsivity-related genes and percentage of premature responses in the MID task and with fMRI BOLD-response in ventral striatum (VS) during reward anticipation. In contrast, no significant association was found between the polygenic scores and anterior cingulate cortex activation. Univariate association analyses revealed that the G allele (major) of the intronic SNP rs6438839 in the KALRN gene was significantly associated with increased VS activation. Additionally, the A-allele (minor) of KALRN intronic SNP rs4634050, belonging to the same haplotype block, was associated with increased frequency of binge drinking.