A major UK study has found that antidepressants can cause significantly different physical side-effects, with some leading to notable weight gain or loss, as well as changes in heart rate and blood pressure.
Researchers from King’s College London and the University of Oxford analysed data from 151 clinical studies, covering more than 58,000 patients taking 30 different antidepressants. They found up to a 4kg difference in average weight change between some drugs — from a 2.5kg loss with agomelatine to a 2kg gain with maprotiline. Nearly half of patients taking maprotiline or amitriptyline experienced weight gain, while more than half using agomelatine lost weight.
Heart rate and blood pressure also varied: the difference between fluvoxamine and nortriptyline reached 21 beats per minute, while blood pressure differences of up to 11 mmHg were noted between certain drugs.
Dr Toby Pillinger from King’s College London said that while antidepressants help many people, “some can lead to meaningful changes in weight, heart rate and blood pressure in a relatively short period.” He noted that SSRIs, the most commonly prescribed class, generally caused fewer physical side-effects.
Co-author Prof Andrea Cipriani from Oxford University urged that the findings should guide shared decision-making between patients and clinicians to ensure more personalised and informed treatment choices.
