As many as one in four people who survive a stroke go on to develop post-traumatic stress disorder (PTSD) within a year, the results of a new study indicate.

A stroke occurs when the blood supply to the brain is interrupted, depriving it of oxygen. As a result, some of the brain cells die and others are damaged. Every year, some 10,000 people in Ireland suffer a stroke and 2,000 people die as a result. Thousands more are left with stroke-related disabilities.

PTSD is an anxiety disorder that can occur after experiencing an intensely stressful event in which grave physical harm occurred or was threatened. It has been well documented in relation to military conflict, but it can also occur as a result of other scenarios, such as road traffic accidents, a violent assault or a serious illness.

Common symptoms include nightmares and high blood pressure and heart rate. If these symptoms continue for more than three months, a person is considered to have chronic PTSD.

Until now, only a few studies have looked at the potential link between stroke and PTSD, so US scientists decided to investigate this further. They analysed the results of nine studies involving over 1,100 survivors of stroke and transient ischaemic attacks (TIA), which are commonly known as ‘mini-strokes'. While mini-strokes do not usually cause any permanent damage, they are a warning sign that a person may be at risk of a major stroke.

The study found that one in four stroke and mini-stroke survivors developed symptoms of PTSD within one year of the event. Furthermore, around one in nine experienced chronic PTSD more than 12 months after the event.

"PTSD is not just a disorder of combat veterans and sexual assault survivors, but strongly affects survivors of stroke and other potentially traumatic acute cardiovascular events as well. Surviving a life-threatening health scare can have a debilitating psychological impact, and health care providers should make it a priority to screen for symptoms of depression, anxiety and PTSD among these patient populations," the scientists said.

They noted that PTSD among stroke survivors appears to be ‘an under-recognised and under-treated problem'.

"Fortunately, there are good treatments for PTSD. But first, physicians and patients have to be aware that this is a problem. Family members can also help. We know that social support is a good protective factor against PTSD due to any type of traumatic event," they explained.

The scientists pointed out that the presence of PTSD can increase a person's risk of suffering another stroke or heart-related event.

"The next step is further research to assess whether mental health treatment can reduce stroke and TIA-induced PTSD symptoms and help these patients regain a feeling of normalcy and calm as soon as possible after their health scare," they added.

Details of these findings are published in the journal, PLOS ONE.