People taking antidepressants may experience significantly different physical side-effects depending on the drug, according to new UK research.
The study, led by King’s College London and the University of Oxford, reviewed 151 clinical trials involving more than 58,000 people and 30 antidepressant types. It found marked differences in weight change, heart rate, and blood pressure across medications — even within the first two months of treatment.
For instance, patients taking maprotiline gained an average of 2kg, while those on agomelatine lost about 2.5kg, a difference of roughly 4kg between drugs. Nearly half of patients using maprotiline or amitriptyline experienced weight gain, while most on agomelatine saw weight loss.
The study also found a 21-beat-per-minute difference in heart rate between fluvoxamine and nortriptyline users, and an 11 mmHg difference in blood pressure between nortriptyline and doxepin.
Dr Toby Pillinger of King’s College London said the findings show antidepressants “are not identical” and can cause “meaningful physical changes” in a short time. He noted that SSRIs, the most prescribed type, generally cause fewer side-effects but said closer monitoring is needed for others.
Professor Andrea Cipriani of Oxford added that the results highlight the importance of shared decision-making between patients and doctors to ensure treatments align with each person’s needs and values.
