Researchers have conducted a study to rank antidepressants based on various side effects experienced during the initial eight weeks of treatment. The team from the Institute of Psychiatry, Psychology & Neuroscience at King”s College London analyzed data from 58,534 participants across more than 150 studies comparing 30 different antidepressants with a placebo.
The findings, published in The Lancet, highlighted notable variations in weight changes, heart rate, and blood pressure among the different medications. The researchers emphasized that these insights should empower patients to discuss their treatment options with healthcare providers.
In the period of 2024/25, approximately 92.6 million antidepressants were prescribed to around 8.89 million patients in England. According to data from the NHS Business Services Authority (NHSBSA), the antidepressant sertraline, known commercially as Lustral, was prescribed to about 2.9 million patients last year. This medication was associated with an average weight loss of 0.76 kilograms and a decrease in heart rate by two beats per minute, although it also caused slight increases in both systolic and diastolic blood pressure.
During the same period, amitriptyline was prescribed to 2.2 million patients. This tricyclic antidepressant resulted in an average weight gain of 1.6 kilograms and an increase in heart rate by nine beats per minute, alongside rises in both systolic and diastolic blood pressure. Notably, amitriptyline is not typically recommended as a first-line treatment for depression; the National Institute for Health and Care Excellence suggests starting with selective serotonin reuptake inhibitors (SSRIs) like sertraline.
Additionally, around 1.4 million patients received citalopram, another SSRI. This medication was linked to an average weight loss of 0.65 kilograms, with reductions in heart rate and systolic blood pressure, though patients did experience a slight rise in diastolic blood pressure.
The study revealed an approximate four-kilogram difference in weight change based on prescribed medications. Patients taking agomelatine lost an average of 2.44 kilograms, while those on maprotiline, which is not commonly prescribed in the UK, saw an average weight gain of 1.82 kilograms. Furthermore, the heart rate variation was significant, with a difference of over 21 beats per minute between fluvoxamine, which lowered heart rate by eight beats per minute, and nortriptyline, which raised it by an average of 13.8 beats per minute.
Researchers noted that every one-kilogram weight gain can elevate a patient”s risk for heart-related issues, while increased blood pressure is associated with a higher likelihood of stroke. However, they acknowledged that a limitation of the study was its focus solely on the first eight weeks of treatment, underscoring the need for further research into the long-term effects of these medications.
Dr. Toby Pillinger, the senior author of the study and a consultant psychiatrist at King”s IoPPN, stated, “While many people benefit from them, these drugs are not identical – some can lead to meaningful changes in weight, heart rate, and blood pressure in a relatively short period.” He added that SSRIs generally exhibit fewer physical side effects, which is reassuring for patients.
Andrea Cipriani, a professor of psychiatry at the University of Oxford, emphasized the importance of shared decision-making in mental health treatment, advocating for collaboration between patients and clinicians to determine the best course of action based on individual preferences and circumstances.
In response to the study, Rosie Weatherly, information content manager at the mental health charity Mind, highlighted the necessity for tailored mental health support that considers personal needs. She encouraged individuals to consult their healthcare providers if they have concerns about side effects from their medications.
Professor Azeem Majeed, chairman of primary care and public health at Imperial College London, reiterated the importance of regular physical health checks for patients on antidepressants, as well as being aware of potential side effects to facilitate informed treatment decisions.
Dr. Lade Smith, president of the Royal College of Psychiatrists, remarked on the crucial role antidepressants play in treating severe depression, particularly when combined with talking therapies, and welcomed the study for enhancing understanding of the physical side effects of various antidepressants.
Professor Kamila Hawthorne, chair of the Royal College of GPs, noted that GPs prescribe antidepressants only when necessary and conduct follow-ups with patients to monitor side effects, emphasizing the importance of medication reviews.
