167 ISSN 1741-0541 Pers. Med. (2014) 11(2), 167–172 part of 10.2217/PME.13.103 © 2014 Future Medicine Ltd Special Report Genotype-based prevention of psychosis onset and schizophrenia: a personalized approach in a target population Schizophrenia imposes a significant burden on public health, affecting approximately 25 million individuals worldwide and generating an extensive healthcare burden. It is important to consider that the disease onset in schizophrenia stems from gene–environment interactions. Early interventions in order to prevent schizophrenia are of high clinical interest, and this is where personalized healthcare and medicine comes in. In this article, we bring a genotype-based personalized, preventive perspective to psychosis onset and schizophrenia. Our objective relies on the possibility of making use of a specific gene–environment interaction in the emergence of schizophrenia as a personalized preventive tool. In particular, we discuss screening of a specific AKT1 allelic variation and its interaction with cannabis use as a preventive approach in a target population with early symptoms of psychosis. Keywords: AKT1฀•฀cannabis฀•฀disease฀onset฀•฀gene–environment฀interaction฀•฀personalized฀ medicine฀•฀psychosis฀•฀schizophrenia Personalized healthcare & medicine In the personalized genomics era, medi- cine and healthcare are moving towards a more individualized approach and towards being predictive, preventive, personalized and participatory [1]. Personalized health- care and medicine bring the advantages of genome-based diagnosis and targeted treat- ment, which require a thorough understand- ing of the molecular bases of diseases [2]. Hence, successful implementation of per- sonalized healthcare and medicine depends on accurate diagnostic tests [3]. Nonethe- less, not all genetic tests precisely predict disease outcomes. This is especially the case when it comes to common complex diseases (CCDs) with environmental risk factors [4]; this is where the power of gene–environment (G×E) interactions comes in. Knowledge integration of the G×E interaction contribu- tions to the emergence of CCDs presents an opportunity for prediction and prevention, as illustrated in this article with a focus on schizophrenia. Schizophrenia as a public mental health issue As a CCD, schizophrenia imposes a signifi- cant burden on public health (PH), affecting approximately 25 million individuals glob- ally [5]. It is a mental disorder with extensive burden on patients, families, societies and healthcare systems worldwide [6–9]. In fact, when compared with some other CCDs, such as diabetes or certain types of cancers, the PH impact of schizophrenia in some cases is higher [10–12]. Indeed, as an example, the disability-adjusted life-years (percentage of total years of life lost to disability or premature death) value for schizophrenia is reported to be 1.1, while this value is 0.4 for cervical cancer and 0.1 for Type 1 diabetes [11]. Schizophre- nia, as the most common form of psychosis, is one of the most severe mental disorders [13,14]. Due to their symptoms, schizophrenia patients suffer from impairments including disruption of relationships, education and occupation, as well as somatic symptoms [15]. Moreover, the prevalence of cardiovascular disease is increased in schizophrenia patients [16], gener- Bahar Taneri* ,1,2 , Mevhibe B Hocaoglu 3 , Angela Brand 2 & Jim van Os 4 1 Department฀of฀Biological฀Sciences,฀ Program฀of฀Molecular฀Biology฀ &฀Genetics,฀Faculty฀of฀Arts฀&฀Sciences,฀ Eastern฀Mediterranean฀University,฀ Famagusta,฀Cyprus 2 Institute฀for฀Public฀Health฀Genomics,฀ Cluster฀of฀Genetics฀&฀Cell฀Biology,฀ Faculty฀of฀Health,฀Medicine฀&฀Life฀ Sciences,฀Maastricht฀University,฀ Maastricht,฀The฀Netherlands 3 Department฀of฀Psychology,฀Faculty฀of฀ Arts฀&฀Sciences,฀Eastern฀Mediterranean฀ University,฀Famagusta,฀Cyprus 4 Department฀of฀Psychiatry,฀Maastricht฀ University฀Medical฀Center,฀Maastricht฀ University,฀Maastricht,฀The฀Netherlands *Author฀for฀correspondence:฀ Tel.:฀+90฀548฀841฀8780 Fax:฀+90฀392฀365฀1604 b.taneri@maastrichtuniversity.nl For reprint orders, please contact: reprints@futuremedicine.com