A diagnosis of diabetes is always stressful. People are suddenly faced with having to manage a complex treatment regimen, including amended diet, regular monitoring and pharmacological therapies, often leading to a variety of new fears and responsibilities about their health. Problems with emotional adjustment to the condition can have negative effects on diabetes self-management – which in turn can impact on emotional wellbeing, in a classical vicious cycle. Here, the authors report on the relationships between diabetes and depression, and suggest a model of collaborative care for people with diabetes and mental health problems.