Common Mental Disorders May Be Linked To An Increased Risk Of Obesity

People with common mental disorders such as depression and anxiety are at increased risk of becoming obese, according to new research published on BMJ today.


The findings also show that individuals with chronic or repeat episodes of common mental disorders are particularly at risk, say the authors.


Previous studies report contradictory results and it remains unclear if common mental disorders lead to an increased risk of obesity, or if obesity is a risk factor for future mental disorders. Understanding the connection between these common conditions is vital because they have a significant impact on health care systems and could aid effective treatment and prevention.


To provide more evidence, researchers led by Mika Kivim?¤ki from University College London, investigated the direction and possible dose-response nature of the link between common mental disorder and obesity.


Their findings are based on four medical screenings of 4,363 British civil servants aged between 35 and 55 years old, over a 19 year period between 1985 and 2004. Each screening included a standardised assessment of common mental disorder (General Health Questionnaire) and measurement of height and weight from which body mass index (BMI) was calculated.


After adjusting for several factors, including use of medicines for mental disorders, weight gain was more common among individuals with common mental disorder symptoms at the start of the study than among those who were symptom free.


Individuals with a common mental disorder at all three preceding screenings were twice as likely to be obese at the final screening compared to symptom free individuals at all previous screenings.


In addition, clear evidence of a dose-response relationship was found, showing that those who experienced more incidences of a common mental disorder had a greater risk of weight gain and obesity.


Interestingly, contrary to some previous research, there was little evidence that obesity leads to common mental disorders in people with no pre-existing mental disorder.


"In this population of British middle-aged adults common mental disorder is predictive of subsequent weight gain and obesity", say the authors, and they call for more research to verify the generalisability of the findings to wider populations.


They conclude by saying that if their observed associations are causal, their findings will have important implications for prevention and treatment.


Although Kivim?¤ki and colleagues found little evidence that obesity predicts depression or anxiety, clinicians should be aware that this association can occur in both directions, say researchers from the University of Adelaide in an accompanying editorial.


They suggest that further research on how best to deliver lifestyle interventions is needed along with government action on taxes, tariffs, and trade laws to encourage the supply and consumption of healthy food and physical activity choices.


Link to paper

Link to editorial



Source
British Medical Journal