A recent review indicates that individuals on specific antidepressants may gain around 2kg (4.5lbs) in the initial two months of therapy, while those on other medications might experience a weight loss of 2.5kg (5.5lbs). Researchers, led by experts from the Institute of Psychiatry, Psychology & Neuroscience (IoPPN) at King’s College London, evaluated data from over 58,000 participants across 150 studies comparing 30 antidepressants with a placebo.
The study highlighted significant variations in weight alterations, heart rate, and blood pressure among the different antidepressants. The findings, published in The Lancet, aim to inform and empower patients, emphasizing the importance of consulting a healthcare provider if any concerns arise.
In the UK, approximately 92.6 million antidepressant prescriptions were issued to an estimated 8.89 million patients in 2024/25. Sertraline, also known as Lustral, was the most prescribed antidepressant, with around 2.9 million patients receiving it last year.
Sertraline was associated with a weight loss of 0.76kg and a decrease in heart rate, but a slight rise in blood pressure. On the other hand, amitriptyline, a tricyclic antidepressant, led to an average weight gain of 1.6kg, increased heart rate, and elevated blood pressure levels.
Apart from treating depression, amitriptyline is also used for pain management and migraines. Citalopram, another commonly prescribed SSRI, was linked to an average weight loss of 0.65kg and improvements in heart rate and blood pressure.
Overall, the research indicated a significant difference in weight changes based on the prescribed antidepressants, with agomelatine resulting in weight loss and maprotiline causing weight gain. Heart rate variations were also notable, with some drugs decreasing it while others increased it significantly.
Researchers underscored the importance of monitoring physical health when using antidepressants, as weight gain can impact heart health and increased blood pressure can raise the risk of stroke. They acknowledged the study’s limitation of focusing on the initial eight weeks of treatment and called for further investigation into long-term effects.
Dr. Toby Pillinger, a senior author of the study, emphasized the need for informed decision-making regarding antidepressant use and highlighted the importance of personalized care. Collaborative decision-making between patients and clinicians was also encouraged to tailor treatments to individual needs and preferences.
Experts from various institutions echoed the significance of routine physical health checks for individuals on antidepressants and emphasized the importance of understanding the potential side effects associated with different medications. They stressed the need for shared decision-making to balance the risks and benefits of antidepressant treatment based on individual circumstances.