A major UK study has found that different antidepressants can produce significantly varied physical 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 over 58,000 patients and 30 types of antidepressants. They discovered that while some drugs cause weight gain, others may lead to weight loss or have minimal impact.
The study found a 4kg difference between certain medications: patients on maprotiline gained about 2kg on average, while those taking agomelatine lost roughly 2.5kg. Nearly half of maprotiline users experienced weight gain, while more than half of agomelatine users lost weight.
Significant differences were also seen in cardiovascular effects — heart rates varied by up to 21 beats per minute, and blood pressure by 11 mmHg, depending on the medication.
Dr Toby Pillinger of KCL said the findings highlight how not all antidepressants are alike. “Some can lead to meaningful changes in weight, heart rate and blood pressure in a relatively short period,” he said. “SSRIs tend to have fewer physical side-effects, which is reassuring, but closer monitoring may be needed for others.”
Professor Andrea Cipriani of Oxford added that the results underscore the need for personalised care and shared decision-making between doctors and patients to ensure treatments align with individual needs and preferences.
