A major UK study has found that different antidepressants can vary significantly in their side-effects, including changes in weight, heart rate, and blood pressure.
Researchers from King’s College London and the University of Oxford analysed data from 151 clinical trials involving more than 58,000 participants who took 30 different antidepressants. They discovered that some medications can lead to noticeable physical changes within just two months of use.
For instance, the drug maprotiline was linked to an average 2kg weight gain, while agomelatine was associated with an average 2.5kg weight loss — a 4kg difference overall. Nearly half of patients taking maprotiline or amitriptyline gained weight, whereas over half of those on agomelatine lost it.
The study also found differences in cardiovascular effects: a 21 beats-per-minute variation in heart rate between people taking fluvoxamine and nortriptyline, and an 11 mmHg difference in blood pressure between nortriptyline and doxepin.
Dr Toby Pillinger from King’s College London said the findings show that while antidepressants are beneficial for many, “these drugs are not identical” and some may warrant closer physical health monitoring.
Professor Andrea Cipriani of Oxford added that the research highlights the need for shared decision-making between patients and clinicians to tailor treatment based on personal needs and preferences.
The researchers are calling for treatment guidelines to be updated to better reflect these differences and promote more personalised antidepressant care.
