Doctors should think twice when prescribing antidepressants as they could pose a risk of diabetes, research has claimed.
A review by the University of Southampton showed that people taking antidepressants are at a higher risk of type 2 diabetes.
The study did not conclude whether the widely prescribed medications are responsible because some antidepressants lead to weight gain - a large driver of type 2 diabetes.
It called for more research into the link and for the medical profession to be alert to the danger.
Dr Katharine Barnard, health psychologist from the university, said: "Antidepressants are used widely in the UK, with a significant increase in their use recently.
"Our research shows that when you take away all the classic risk factors of type 2 diabetes - weight gain, lifestyle etc - there is something about antidepressants that appears to be an independent risk factor.
"With 46 million prescriptions a year, this potential increased risk is worrying.
"Heightened alertness to the possibility of diabetes in people taking antidepressants is necessary until further research is conducted."
Richard Holt, a professor in diabetes and endocrinology at the university, said: "While depression is an important clinical problem and antidepressants are effective treatments for this debilitating condition, clinicians need to be aware of the potential risk of diabetes, particularly when using antidepressants in higher doses or for longer duration.
"When prescribing antidepressants, doctors should be aware of this risk and take steps to monitor for diabetes and reduce that risk of diabetes through lifestyle modification."
Academics assessed 22 studies and three previous systematic reviews that looked into the effects of antidepressants on diabetes risk.
Overall, it found people taking antidepressants were more likely to have diabetes, which affects around 2.5 million people in the UK and is at epidemic proportions, Diabetes UK has previously said.
The use of antidepressant medication has risen sharply over recent years, reaching 46.7 million prescriptions in the UK in 2011.
The researchers warned that different types of antidepressants might carry different risks, and long-term prospective randomised control trials were needed to look at the effects of individual tablets.
Published in Diabetes Care, the team said there are "several plausible" reasons why antidepressants are associated with an increased risk of diabetes in addition to significant weight gain.
The research found that several studies which explored this association still observed an increased risk of diabetes after adjustment for changes in body weight, implying other factors could be involved.
The conclusion to the report said: "From the evidence reviewed, there is a link between antidepressant use and diabetes, but causality is not established.
"Long-term prospective studies are required to assess this relationship further, but in the interim, caution is advised and a heightened alertness to the potential risk of diabetes is necessary, not least because of the large numbers of antidepressants that are prescribed."