A new study from King’s College London has found that most people who take selective serotonin reuptake inhibitors (SSRIs), a common type of antidepressant, report feeling better.
The research, published in Psychological Medicine, analyzed nearly 20,000 people who had used SSRIs and found that about 75% said the medication helped them.
However, the study also identified key factors that influence how well antidepressants work for different people.
How the Study Was Conducted
The researchers examined data from the UK Biobank, a large health database, and focused on 19,516 people who had used SSRIs such as citalopram, fluoxetine, paroxetine, or sertraline for at least two weeks.
Instead of relying on doctors’ assessments, the study asked participants directly if the medication had helped them feel better. Their answers included “yes, at least a little,” “no,” “don’t know,” or “prefer not to answer.”
The results showed that:
- 74.9% of participants felt SSRIs helped them.
- 18.8% said the medication was not helpful.
- The rest were unsure or did not answer.
Who Is More Likely to Benefit from SSRIs?
The researchers looked at various factors that might explain why some people find antidepressants effective while others do not. They found that:
- Age, gender, and income play a role – Older adults, men, and people with lower incomes were more likely to report that SSRIs did not work for them.
- Substance use affects response – People who reported using alcohol or illicit drugs were less likely to find antidepressants helpful.
- Depression severity matters – Those whose worst episode of depression lasted more than two years or who felt no mood improvement even during positive life events were less likely to benefit from SSRIs.
- Genetics may influence effectiveness – People with a higher genetic risk for depression, based on polygenic risk scores, were also less likely to find antidepressants helpful.
Why These Findings Matter
The study’s authors believe these results help clarify the public debate over antidepressants. Dr. Michelle Kamp, the study’s lead author, said, “While antidepressants don’t work for everyone, our findings provide strong support for their effectiveness, with three-quarters of users reporting improvement.”
Previous studies have mostly relied on doctors’ observations to measure how well antidepressants work. This study, however, focused on patients’ own experiences, showing that self-reported benefits align with clinical findings.
Professor Andrew McIntosh from the University of Edinburgh emphasized that while clinical trials prove that antidepressants work better than placebos, they do not explain why some people respond better than others. “We now need to focus on understanding how antidepressants work and how to predict who will benefit the most,” he said.
Limitations and Future Research
While the study provides valuable insights, it has some limitations. Because it relies on self-reported experiences, there is a chance that participants’ memories or perceptions could be inaccurate. Additionally, the sample may not fully represent the general population, as it comes from a health database rather than a random selection of antidepressant users.
Mental health experts, including Cat Sebastian from Wellcome, believe studies like this are crucial for developing better, more personalized treatments for depression. Understanding why antidepressants work well for some people but not others could help researchers design new medications or treatment strategies tailored to individual needs.
Takeaway
This large-scale study confirms that SSRIs help most people with depression, but they do not work for everyone. Factors such as age, substance use, severity of depression, and genetics can influence how well someone responds to antidepressants.
Future research will focus on identifying the best ways to match people with the right treatment, making depression care more effective and personalized.
If you care about depression, please read studies about how dairy foods may influence depression risk, and B vitamins could help prevent depression and anxiety.
For more information about mental health, please see recent studies that ultra-processed foods may make you feel depressed, and extra-virgin olive oil could reduce depression symptoms.
The research findings can be found in Psychological Medicine.
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