Data from the UK Clinical Practice Research Datalink was used to examine long-term association between consumption of antidepressant and weight gain
A new study conducted by researchers from King’s College London revealed a link between long-term use of antidepressants and sustained weight gain. The study was published in the British Medical Journal in May 2018. The results were found to be consistent after examining factors such as sex, age and other health parameters. Furthermore, the study found consistent increase in the weight regardless of the individual’s starting weight.
As a part of study, medical data of over 300,000 adults were collated and monitored. Results of the study concluded that increasing consumption of antidepressant can significantly contribute to weight gain. Associated weight gains on antidepressants were recorded during the second and third years of treatment. Across the second year of treatment with an antidepressant, subjects were 46% more likely to gain five percent more weight as compared to people who are not taking antidepressants. Results by individual antidepressant drugs revealed most agents resulted in similar levels of weight gain. Among which, Mirtazapine, displayed a notably higher correlation with weight gain.
However, interpreting results from a large-scale observational study was a major challenge faced by researchers, as various conditions such as depression is also interrelated with obesity, which makes it difficult to suggest if the weight gain is due to antidepressant drug or any other condition. The authors acknowledge the limitations of this observational study, but suggest its findings could help confirm previously reported causal associations between initiating antidepressant treatments and weight gain based on the large number of study participants and length of follow up.