The way that we support people with mental health problems is based on a flawed paradigm. It assumes that physical and mental health are fundamentally different (albeit each having some impact on the other), requiring different specialist approaches, and ignores the common factors in the global determination of health and illness, which have biological, psychological and, in particular, social components. To achieve integrated healthcare, policy-makers, service planners and commissioners need to better understand the indivisibility and unitary nature of physical and mental health, which means that distinguishing between them is likely to lead to an incomplete response to people’s needs as well as flawed thinking about mental health. In addition, they should focus on major social and structural influences such as education, unemployment, housing, poverty and discrimination, rather than just on support given to individuals based on a medical diagnosis of mental illness. Such support can clearly have a positive effect but may be limited in the extent to which it can improve health by mitigating adverse social factors.