A large study led by researchers at King’s College London and the University of Oxford has found that different antidepressants can cause significantly different physical side-effects, including variations in weight gain, heart rate, and blood pressure.
The review analysed data from 151 clinical trials involving more than 58,000 people, comparing 30 antidepressants over an average of eight weeks. The results showed that some drugs could cause as much as 2kg (4.5lbs) of weight gain, while others were linked to equivalent weight loss.
For example, patients on maprotiline gained around 2kg on average, while those taking agomelatine lost up to 2.5kg. Nearly half of those on maprotiline or amitriptyline experienced weight gain, compared with over half of agomelatine users losing weight.
The researchers also found significant cardiovascular differences — including a 21-beat-per-minute variation in heart rate between fluvoxamine and nortriptyline, and an 11 mmHg difference in blood pressure between nortriptyline and doxepin.
Dr Toby Pillinger from KCL said the findings show 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 added that SSRIs tend to have fewer physical side-effects but that “closer health monitoring may be warranted” for others.
Professor Andrea Cipriani of Oxford emphasised the need for “shared decision-making” between patients and doctors to tailor treatment choices based on individual health needs and preferences.
