The long-term outcome of patients with both diabetes and schizophrenia remains unclear.

To explore whether having schizophrenia increases the risk of advanced complications and mortality in people with diabetes.

This is a population-based matched cohort study using Taiwan's National Health Insurance Research Database. A total of 11 247 participants with diabetes and schizophrenia and 11 247 participants with diabetes but not schizophrenia were enrolled. We used Cox proportional hazard models to determine the effect of schizophrenia on macrovascular and microvascular complications, and all-cause mortality.

The adjusted hazard ratios were 1.49 (95% CI 1.32–1.68) for macrovascular complications, 1.05 (95% CI 0.91–1.21) for microvascular complications and 3.68 (95% CI 3.21–4.22) for all-cause mortality in patients with diabetes and schizophrenia compared with those patients with diabetes but not schizophrenia.

Patients with both diabetes and schizophrenia had an increased risk of macrovascular complications and all-cause mortality but did not have statistically significant elevated risk of microvascular complications.

The National Institute of Health's (NIH's) emphasis on mental illness as a brain disorder has transformed psychiatric research and attitudes towards mental illness. Despite the departure of the Director of the National Institute of Mental Health, Thomas Insel, to join Google Life Sciences (http://www.nih.gov/about/director/09152015_statement_insel.htm), the move away from symptom-based diagnoses in favour of more neuroscientific rationales for diagnosis is necessary and likely to be sustained. The absence of demonstrable organic pathology in mental illnesses motivated the NIH programmes, yet essentially all behaviours and adaptations to context will have physiological correlates; Google and other software and technology companies may well offer better and more powerful methods for assessing pathophysiology and making diagnoses in the future. Such shifts in diagnostic practice require much disciplined research, and seem to not obviate the need for compassionate, caring and emotionally intelligent clinicians who are able to contain and negotiate meanings and experiences, and transform conversations and care packages to positive outcomes for patients.