Psychiatry is an important medical speciality, and several topics on the diagnosis, treatment and prevention of mental disorders are currently being debated. The area of diagnosis has attracted much dialogue with the recent launch of the DSM-5; the 5th edition of the Diagnostic and Statistical Manual of Mental Disorders. Development of a new psychiatric classification system, Research Domain Criteria (RDoC), by the National Institute of Mental Health in 2009, is a decade-long research framework, that aims to incorporate genetics, neuroimaging and cognitive science with a move towards precision medicine for mental disorders. Mental disorders are associated with physical health problems and there are many initiatives to make mental health a key public health priority. For example, depression is known to increase the risk of cardiovascular disease, stroke, diabetes and obesity morbidity. Emerging evidence is showing that risk factors for common mental disorders like anxiety include lifestyle behaviors such as diet, physical inactivity and smoking. Understanding the relationship between physical and mental health will help drive prevention strategies in mental health by building on established schemes and developing approaches used for noncommunicable somatic diseases. This article collection on the current controversies in psychiatry seeks to address the key challenges in mental health from diagnosis to co-morbidities. The series also focuses on precision medicine where advances in genetics, epigenetics, biomarkers, treatment response and environmental factors will facilitate understanding of vulnerability and the requirement of specific therapies for mental disorders. Further submissions of original research, reviews and debates focusing on the controversies and open questions in psychiatry are encouraged.