A landmark scientific review has ranked the physical health side effects of antidepressants for the first time, revealing significant differences between commonly prescribed medications.
The study found that some antidepressants could cause patients to gain up to two kilograms in weight within the first eight weeks of treatment, while others affected heart rate by as much as 21 beats per minute.
Researchers said these variations were large enough to influence a patient’s long-term health, treatment success and ability to continue with their prescribed medication.
With around eight million people in the United Kingdom currently taking antidepressants, the findings could have major public health implications.
The researchers cautioned that patients should not stop taking their medication but urged doctors to match antidepressant prescriptions more carefully to each individual’s medical needs.
“There are big differences between antidepressants and this is important not just for individual patients but for the wider population,” said Professor Oliver Howes, one of the study’s lead authors. “Even modest changes can have a major effect when millions of people are affected.”
The study, conducted by experts from King’s College London and the University of Oxford, is the first to provide a clear ranking of the physical health effects of antidepressant drugs.
Researchers analyzed data from 151 separate studies involving more than 58,500 patients who were prescribed 30 different antidepressant medications.
“Clearly no two antidepressants are built the same,” said Dr Atheeshaan Arumuham from King’s College London. “We now have robust data showing how these drugs differ in their impact on the body.”
The analysis revealed that some antidepressants are associated with a higher risk of weight gain, increased heart rate and metabolic changes that can raise the risk of cardiovascular problems.
Researchers warned that long-term exposure to these physical effects could contribute to conditions such as high blood pressure, heart attack and stroke.
This means that two people with the same depression diagnosis might require different antidepressants based on their existing health conditions and personal preferences.
Dr Toby Pillinger, another lead researcher, told The Daily National News that the effects were evident even in short-term studies. “Most of the studies we looked at were eight weeks in duration, and even in that period we observed large changes in physical health that have clear clinical relevance,” he said.
Dr Pillinger stressed that the findings were not meant to alarm patients but to help them make informed decisions about their treatment. “The last thing I want is for this story to scare people,” he said. “I want it to empower individuals to engage in shared decision-making with their practitioners.”
The ranking system developed by the research team is designed to help healthcare professionals choose antidepressants that minimize health risks based on a patient’s medical profile.
For example, certain medications were found to have minimal effects on heart rate, making them safer options for people with cardiovascular disease. Others were linked to less weight gain, which could be beneficial for patients with obesity or diabetes concerns.
The study also emphasized that side effects are not the same for everyone and can depend on factors such as genetics, age and existing health conditions.
Dr Arumuham noted that while antidepressants can be life-changing for those struggling with depression, it is crucial to consider the physical as well as psychological impacts of treatment. “The goal is to treat depression without compromising physical wellbeing,” he said.
In a practical example, the researchers illustrated how three patients with identical depression diagnoses could require very different prescriptions.
In the scenario, Sarah, 32, wanted to avoid weight gain, John, 44, had high blood pressure, and Jane, 56, had elevated cholesterol levels.
Dr Pillinger told The Daily National News that each would likely benefit from a different antidepressant tailored to their health needs. “It highlights the importance of personalized care,” he said.
Experts say the new ranking will make it easier for general practitioners and psychiatrists to weigh physical side effects alongside mental health benefits when selecting treatments.
They also called for further research into how antidepressants affect long-term physical health, noting that most available data only covers short-term use.
Antidepressants remain a vital component of depression treatment, and the researchers reiterated that patients should always consult their doctor before making any changes to medication.
The findings are expected to influence clinical guidelines and encourage more holistic approaches to managing depression across healthcare systems.
