Neuropsychiatric effects of caffeine

Anthony Winston is a consultant in eating disorders with South Warwickshire Primary Care Trust (Eating Disorders Unit, Woodleigh Beeches Centre, Warwick Hospital, Lakin Road, Warwick CV34 5BW, UK. E-mail: Anthony.Winston{at}SWarkPCT.nhs.uk) and an honorary senior lecturer in psychiatry at the University of Warwick. Elizabeth Hardwick is a specialist registrar in general adult psychiatry on the West Midlands rotation and Neema Jaberi is a graduate medical student at the University of Warwick.

Psychiatrists rarely enquire about caffeine intake when assessing patients. This may lead to a failure to identify caffeine-related problems and offer appropriate interventions. Excessive caffeine ingestion leads to symptoms that overlap with those of many psychiatric disorders. Caffeine is implicated in the exacerbation of anxiety and sleep disorders, and people with eating disorders often misuse it. It antagonises adenosine receptors, which may potentiate dopaminergic activity and exacerbate psychosis. In psychiatric in-patients, caffeine has been found to increase anxiety, hostility and psychotic symptoms. Assessment of caffeine intake should form part of routine psychiatric assessment and should be carried out before prescribing hypnotics. Gradual reduction in intake or gradual substitution with caffeine-free alternatives is probably preferable to abrupt cessation. Decaffeinated beverages should be provided on psychiatric wards.