Nearly nine million people in England, approximately one in six of the population, were prescribed antidepressants in the past year. While these medications are recognized for their effectiveness in managing depression and anxiety by influencing serotonin levels, a significant portion of patients are now taking them for extended periods. Official figures indicate that about half of those on antidepressants have used them for over two years, and roughly two million have been on them for more than five years.
Some experts are questioning whether the benefits of prolonged antidepressant use are being overstated, citing emerging research that links long-term use to a range of serious health concerns. These potential side effects include heart problems, such as an increased risk of sudden cardiac death, as well as weight gain, weakened bones, fractures, sexual dysfunction, type 2 diabetes, and cognitive decline. While definitive causal links are still being established for many of these conditions, a growing body of evidence suggests that patients should not take these medications longer than medically necessary.
Professor Joanna Moncrieff, a psychiatrist at University College London, noted that research on the long-term effects of antidepressants is limited and often of low quality. Her review, which focused on individuals taking the pills for over a year, found associations with type 2 diabetes, weight gain, and increased falls and fractures in older adults. "We certainly can’t say that long-term antidepressants are safe or harmless, because we have not done enough research to know that," Moncrieff stated, emphasizing the need for shorter treatment durations to mitigate harm.
Dr. Sameer Jauhar, a psychiatrist at Imperial College London, highlighted that different antidepressants have varying long-term effects, particularly on the cardiovascular system, which should inform prescribing decisions. Current guidelines from the National Institute for Health and Care Excellence (NICE) suggest considering antidepressant discontinuation after at least six months of significant symptom improvement, with options for longer use for recurrent depression.
However, patients are often not adequately warned about the additional risks associated with prolonged use. This is partly due to the complexity of disentangling drug effects from the underlying condition, as individuals with depression are already at higher risk for several chronic diseases, including heart disease and type 2 diabetes, due to lifestyle factors associated with the illness. Professor Glyn Lewis from University College London acknowledged that while many observational studies show associations, they cannot prove causation, but stressed the importance of taking these findings seriously.
Dr. David Healy, who has extensively researched antidepressant side effects, believes the harms are biologically plausible, given that serotonin receptors are present throughout the body, not just in the brain. He drew parallels to the long-term risks associated with antibiotics, which are generally safe in the short term but can become problematic over extended periods.
Some of the most concerning potential effects involve the heart. Older types of antidepressants, such as serotonin-norepinephrine reuptake inhibitors (SNRIs) and tricyclic drugs, can increase levels of noradrenaline, a hormone linked to increased heart rate, blood pressure, and cholesterol. More significantly, some research suggests antidepressants may prolong the QT interval on an electrocardiogram, a factor that can lead to dangerous heart rhythm disturbances and, in rare cases, sudden cardiac death. A 2025 study presented to the European Society of Cardiology found that using antidepressants for one to five years increased the risk of sudden cardiac death by 56 percent, with the longest users facing the greatest risk.
Type 2 diabetes is another area where a clearer link is emerging. While weight gain associated with antidepressants may contribute, researchers also suspect the drugs might interfere with the body's blood sugar regulation. Evidence also points to an increased fracture risk, particularly in individuals over 50 taking SSRIs or tricyclic antidepressants, with risk increasing the longer the medication is used. The connection to dementia is less certain, as depression itself is a significant risk factor, making it challenging to isolate the drugs' effects.
Furthermore, long-term use can exacerbate withdrawal symptoms, which can include anxiety, agitation, and flu-like symptoms. Experts advise patients against abruptly stopping medication and recommend consulting a healthcare professional for a gradual tapering process.
Dr. Alison Cave, MHRA chief safety officer, stated that side effects are outlined in patient information leaflets and emphasized that patients should not alter their treatment without consulting a healthcare professional. Anyone concerned about potential side effects should speak with their doctor or pharmacist.