Patients with bipolar disorder or schizophrenia have a high risk of out-of-hospital cardiac arrest compared with the general population, a study has found.

Researchers say the excess risk is not just because of cardiovascular risk factors as they have found medication poses an independent risk.

Users of antipsychotics — but not antidepressants or lithium — put patients at higher risk than nonusers, the Danish researchers say.

Although the link between severe psychiatric disorders and adverse cardiovascular outcomes is already known, the findings suggest the need for improved management and early screening of these patients, they wrote in Heart.