Depression is “an important risk factor for acute stroke”, according to an analysis of the INTERSTROKE study.

The study enrolled 13,392 stroke patients and 13,485 controls from 32 countries.
The prevalence of depression (feeling sad, blue, or depressed for at least two consecutive weeks during the previous 12 months) was 18.3 per cent among people who experienced a first acute stroke and 14.1 per cent among controls. 

Allowing for other risk factors, depression increased the risk of: 

• Acute stroke by 46 per cent
• Intracerebral haemorrhage by 56 per cent 
• Ischaemic stroke by 44 per cent.     

The association was stronger in men (60 per cent) than women (31 per cent). 

Stress and depression seem to be inter-related. After also allowing for work stress, home stress and financial stress, depression increased the risk of acute stroke by 31 per cent, intracerebral haemorrhage by 22 per cent and ischaemic stroke by 36 per cent. 

Researchers assessed depression severity by asking about: loss of interest in activities; feeling tired; weight change; trouble sleeping; trouble concentrating; thinking of death; and feeling worthless. 

Acute stroke risk was 35 per cent higher with mild (one to two symptoms), 58 per cent higher with moderate (three to four symptoms) and 54 per cent higher with severe (five to seven symptoms) depression. 

Depression did not seem to influence stroke severity. “Our results show [that] depressive symptoms were linked to increased stroke risk and the risk was similar across different age groups,” says Dr Robert Murphy of the University of Galway, Ireland. (Neurology DOI: 10.1212/WNL.0000000000207093)