Background. Previous researches have suggested that late onset mania is a distinct subtype associated with medical and neurological disorders. Few studies, however, have focused on vascular risk factors.

Methods. Records of 366 bipolar patients were reviewed and age of first psychiatric hospitalization determined. Late-onset cases were determined empirically from a distribution histogram. Late onset cases were matched to early onset cases and histories of vascular disease/risks and current cholesterol levels compared.

Results. The distribution of age of first psychiatric hospitalization was bimodal with an intermode at age 47. Using that threshold, 6·3% of the cohort was classified as having late onset mania. Vascular risks factors were greater and current cholesterol levels higher in the late onset group.

Conclusions. Late onset mania is associated with greater vascular risk factors. The bimodal appearance of age of first psychiatric hospitalization in this study provides further support of late onset mania as a distinct manic subtype with possibly a different, vascular aetiology. Control of these vascular risks may impact on the incidence of late onset mania, as well as on its clinical management.