MedWire News: Patients with bipolar disorder have a greater risk of developing cancer than the general population, results of an Israeli study suggest.

For people with the mood disorder, the findings emphasise the importance of maintaining a healthy lifestyle, say the researchers.

Explaining the reasons for their study, Dr Itzhak Levav, from the Ministry of Health in Jerusalem, and colleagues write: "Several... studies have focused on the association of schizophrenic disorders and the risk for cancer among patients and their first-degree relatives."

But they add: "In contrast, there is limited recent research on a similar association for bipolar disorder."

To investigate, the researchers studied the incidence of cancer among 2121 Israelis who received hospital treatment for bipolar disorder between 1980 and 2005.

The team then compared the findings with the incidence of cancer among the general population of Israel during the same period.

Analysis revealed that, compared with the general population, men with bipolar disorder were 1.59 times more likely to develop any type of cancer, while women with the mood disorder were 1.75 times more likely to develop any type of cancer.

Dr Levav and team write: "We found a clear enhanced risk for cancer among patients with bipolar disorder."

The researchers explain that one reason for their findings could be that people with bipolar disorder are more likely to engage in unhealthy and risky activities, such as smoking and drug taking, and are more likely to be overweight than people without the mental health disorder.

They therefore conclude "that it is incumbent upon the medical and psychiatric services to be on the alert [for cancer], particularly since there is a tendency to overlook physical disorders in patients affected by severe mental disorders."

The research is published in the Journal of Affective Disorders.