Study shows OCD may raise risk of death

London: People with obsessive-compulsive disorder (OCD) may have an increased risk of death from both natural and unnatural causes than those without the disorder, finds a study.

OCD is typically a long-term psychiatric disorder affecting about 2 per cent of the population.

It is characterised by intrusive thoughts, urges or images that trigger high levels of anxiety and other distressing feelings -- known as obsessions -- that the person tries to neutralise by engaging in repetitive behaviours or rituals -- known as compulsions.

OCD is also associated with academic underachievement, poor work prospects, alcohol and substance use disorders, and an increased risk of death.

The study, published in The BMJ, revealed that the people with OCD had increased odds of natural causes of death, like respiratory system diseases (73 per cent), mental and behavioural disorders (58 per cent), diseases of the genitourinary system (55 per cent), endocrine, nutritional, and metabolic diseases (47 per cent), diseases of the circulatory system (33 per cent), nervous system (21 per cent), and digestive system (20 per cent).

Among the unnatural causes, suicide showed the highest risk of death (a nearly fivefold increased risk), followed by accidents (a 92 per cent increased risk).

The researchers from Karolinska Institutet in Sweden point out that many of the natural causes of death are preventable, suggesting that better surveillance, prevention, and early intervention strategies should be implemented to reduce the risk of fatal outcomes in people with OCD.

The risk of all-cause death was similar in both women and men, although women with OCD had a higher relative risk of dying due to unnatural causes than men with OCD, likely due to the lower baseline risk among women in the general population, said the researchers.

In contrast, people with OCD had a 10 per cent lower risk of death due to tumours (neoplasms).

For the study, the researchers used data of 61,378 Swedish people with OCD and 613,780 individuals without OCD matched and a further sibling group of 34,085 people with OCD and 47,874 without OCD.

Average age at OCD diagnosis was 27 years and groups were monitored for an average of 8 years from January 1973 to December 2020.

Overall, people with OCD had a higher death rate than matched individuals without OCD (8.1 versus 5.1 per 1,000 person-years, respectively).

People with OCD had an 82 per cent increased risk of death from any cause. The excess risk of death was higher for both natural (31 per cent increased risk), and particularly, unnatural causes of death (a 3-fold increased risk).

“This is an observational study, so it can't establish the cause,” the researchers said.