A major UK study has found that antidepressants vary widely in their physical side-effects, with some causing significant weight gain, while others lead to weight loss or changes in heart rate and blood pressure.
Researchers from King’s College London and the University of Oxford analysed data from 151 clinical studies involving more than 58,000 participants, comparing 30 commonly prescribed antidepressants.
They found weight changes of up to 4kg between different drugs. Patients taking maprotiline gained about 2kg on average, while those on agomelatine lost around 2.5kg. Nearly half of people on drugs like maprotiline or amitriptyline experienced weight gain, whereas most patients on agomelatine lost weight.
Heart rate differences of up to 21 beats per minute and blood pressure changes of 11 mmHg were also recorded between certain medications.
Lead author Dr Toby Pillinger said the results highlight how antidepressants “are not identical” and can affect physical health differently. He added that SSRIs, the most commonly used antidepressants, “tend to have fewer physical side-effects,” but patients on others may need closer monitoring.
Professor Andrea Cipriani from Oxford emphasised the importance of “shared decision-making” between patients and clinicians to choose the most suitable treatment based on individual needs and health risks.
