People taking antidepressants can experience significant differences in physical side-effects depending on the medication, according to new UK research. The study found that some antidepressants can lead to up to 2kg of weight gain within two months, while others can cause comparable weight loss.
The analysis, conducted by King’s College London and the University of Oxford, examined data from 151 clinical studies involving more than 58,000 participants and 30 different antidepressants. It revealed notable variations in weight change, heart rate, and blood pressure across different drugs.
For instance, average weight changes ranged from a 2.5kg loss with agomelatine to a 2kg gain with maprotiline. Almost half of those on maprotiline or amitriptyline gained weight, while more than half taking agomelatine lost weight. Heart rate varied by as much as 21 beats per minute between fluvoxamine and nortriptyline users, and blood pressure differed by up to 11 mmHg between nortriptyline and doxepin.
Dr Toby Pillinger of King’s College London said the results highlight how antidepressants can have “meaningful changes in weight, heart rate, and blood pressure in a relatively short period,” and that SSRIs generally cause fewer physical side-effects.
Professor Andrea Cipriani from Oxford added that the findings stress the importance of shared decision-making between patients and clinicians to ensure treatment reflects individual needs and values.
Researchers are now urging updates to clinical guidelines to help patients and doctors choose antidepressants with a clearer understanding of their potential physical effects.
