Antidepressants usage may be linked to the health issues of weight gain and obesity, according to a new study by researchers from King's College London.
Scientific studies have shown chicken-and-egg scenarios of obesity increasing the risk of developing depression, and depression being a predictor for obesity. The new study, meanwhile, establishes a new connection between the two in the form of antidepressant prescriptions.
Antidepressants Linked To Weight Gain And Obesity
"Patients who were normal weight were more likely to transition to overweight, and overweight patients were more likely to transition to obesity if they were treated with antidepressants," said Rafael Gafoor, King's College London primary care and public health researcher and coauthor of the study.
The researchers analyzed data from the UK Clinical Practice Research Datalink, which is a large collection of electronic health records from people across the nation. The study, which involved nearly 295,000 people of varying weights, monitored the antidepressant use and weight gain of the subjects.
According to the findings, people who were prescribed with antidepressants in the first year of the study were 21 percent more likely to have gained at least 5 percent of their initial weight over the next 10 years, compared to people who were not prescribed with the drugs. The risk for weight gain appeared to be highest in the second and third year of taking antidepressants, when the risk of becoming overweight or obese was up by 29 percent.
The researchers found that factors such as age, gender, and the presence of other health problems such as cancer or diabetes did not have much of an effect on the results.
Some Antidepressant Drugs Worse Than Others
Not all antidepressant drugs were equal in increasing the risk of weight gain and obesity though. Some drugs resulted in a higher risk compared to others.
For example, mirtazapine was particularly bad, as it was linked to a 50 percent higher risk of at least 5 percent weight gain. While mirtazapine is now rarely prescribed in the United Sates, it is the most common type of antidepressant prescribed in the UK's National Health Service for people who are not able to tolerate the first choice, which are the selective serotonin reuptake inhibitors or SSRIs.
The study, however, was observation, despite its large sample size. This means that it could not be definitely said that taking antidepressants leads to gaining weight. A higher risk of weight gain and obesity may not be on the minds of people as antidepressants side effects, so the study is doing its purpose of raising awareness for the matter.