Taylor et al (Reference Taylor, Young and Esop2004) found very low rates of monitoring for diabetes in their study population. Less than 50% were tested, and the testing rates varied with the antipsychotic prescribed.

So why is this the case? This probably reflects the lack of a clear consensus in this area. There is currently no consistent direction for doctors regarding the need for monitoring for diabetes. The conflicting evidence in the literature is abundant. For example, the British National Formulary is probably the most widely used reference for prescribers in the UK. The current edition makes no mention of blood sugar abnormalities with typical antipsychotics, quetiapine and risperidone. Concerns are mainly highlighted with olanzapine and clozapine. This is despite studies showing increased risks with typical and atypical antipsychotics. Furthermore, the recent Maudsley Guidelines give some suggestions of the type and frequency of tests, focus mainly on olanzapine and clozapine but contradict the British National Formulary in suggesting testing for all antipsychotics.

So is testing important? Evidence is mounting of an association between schizophrenia and diabetes. Ryan & Thakore (Reference Ryan and Thakore2002) give schizophrenia as an independent risk factor for diabetes even in antipsychotic-naïve patients. The PORT study (Reference Dixon, Weiden and DelahantyDixon et al, 2000) gives a prevalence of 15% in this population compared with 3% in the general population (Reference Bennett, Dodd and FlatleyBennett et al, 1995). Several studies suggest an even higher risk of diabetes in those prescribed atypical antipsychotics (Reference Bushe and LeonardBushe & Leonard, 2004). Therefore, it appears that people with schizophrenia are a high-risk group for developing diabetes and its potential consequences.

Our patients may have little contact with other doctors and diabetes can be a silent illness which could be easily missed. Psychiatrists are well placed to monitor this high-risk population and should be encouraged to adopt a holistic approach. There is a need for clear consensus to avoid any confusion among psychiatrists. Guidelines are needed to help clinicians to decide which patients should be tested, the type of test to use and how often. The Royal College of Psychiatrists is well placed to publish the necessary guidelines.