Introduction

Type 2 diabetes mellitus is an extremely common, lifelong health condition. According to latest figures from Diabetes UK, 2.9 million people are known to suffer from diabetes in the UK while another 850 000 remain undiagnosed. By 2025 there will be more than 4 million people with diabetes in the UK. In England the current prevalence of diabetes is estimated at around 5.5%. Type 2 diabetes is a global epidemic with an estimated worldwide prevalence of 8.3% (366 million) in 2011 that is forecast to rise to 9.9% (552 million) in 2030. In addition, 280 million people have impaired glucose tolerance that is forecast to increase to 398 million by 2030.

While the above numbers are of concern, even more worrying is the fact that the proportion of people with diabetes among patients with severe mental illness is much higher. The prevalence of diabetes in schizophrenia has been found to be about 20% and depression is associated with a 60% increase in rates of type 2 diabetes. In addition, diabetes is considered to be one of the most psychologically demanding of the chronic medical illnesses and is often associated with several psychiatric disorders, including depression. According to a large meta-analysis, the prevalence of depression in diabetes was found to be 17.6% v. 9.8% in the general population. The prevalence of depression in diabetes was also reported to be higher in women (23.8%) than in men (12.8%).

Physical symptoms and signs

The symptoms of type 1 and type 2 diabetes are similar.