Depression raises the risk of cardiovascular disease and mortality both rich and poor nations, and particularly in cities, a study suggests.

Based on data from nearly 146,000 adults in 21 countries with a median follow up of nine years, risk for combined cardiovascular events and death was 18% higher in people with four or more depressive symptoms compared with no symptoms, researchers report.

The risk rose 23% in urban areas compared with 10% in rural settings in this group, the authors wrote in JAMA Psychiatry.

Even after accounting for known risk factors such as diabetes and hypertension, adults who reported symptoms of depression at the start had a 14% increased risk of incident cardiovascular disease, a 23% increased risk of myocardial infarction and a 17% increased risk of all-cause mortality.