Experts said it is 'too early' to say whether the drugs could be used in clinical practice
Researchers have analysed data from 20 clinical trials involving the use of anti-cytokine drugs which are used to treat a range of autoimmune inflammatory diseases such as arthritis.
The side-effects of the treatments showed a ‘significant’ antidepressant effect from the drugs, compared to a placebo, based on results from of seven trials.
Scientists from Cambridge University have analysed the clinical trials and found that the drugs led to an improvement in the severity of depressive symptoms independently of improvements in physical illness.
Dr Golam Khandaker said: "It's becoming increasingly clear to us that inflammation plays a role in depression, at least for some individuals, and now our review suggests that it may be possible to treat these individuals using some anti-inflammatory drugs.
"These are not your everyday anti-inflammatory drugs such as ibuprofen, however, but a particular new class of drugs."
When people are are exposed to an infection, for example flu or a stomach bug, our immune system fights back to control and remove the infection.
During the process, immune cells flood the blood stream with proteins known as cytokines. The process is known as systemic inflammation.
Even when people are healthy, the body carries trace levels of these proteins which rise in response to infection.
Inflammation can also occur as a result of the immune system mistaking healthy cells for infected cells and attacking the body.
The findings were published in the journal Molecular Psychiatry
This process can lead to autoimmune inflammatory diseases such as rheumatoid arthritis and Crohn's disease.
Professor Peter Jones, co author of the study, said: "It's too early to say whether these anti-cytokine drugs can be used in clinical practice for depression, however.
"We will need clinical trials to test how effective they are in patients who do not have the chronic conditions for which the drugs have been developed, such as rheumatoid arthritis or Crohn's disease.
"On top of this, some existing drugs can have potentially serious side effects, which would need to be addressed."
The researchers believe that anti-inflammatory drugs may offer hope for patients for whom current antidepressants are ineffective.
Although the trials reviewed by the team involve physical illnesses that trigger inflammation - and hence potentially contribute to depression - their previous work found a connection between depression and levels of inflammation in healthy people, which can be caused by factors such as genes and psychological stress.
Clinical trials have revealed anti inflammatory drugs could ease symptoms of the illness
Dr Khandaker added: "About a third of patients who are resistant to antidepressants show evidence of inflammation.
"So, anti-inflammatory treatments could be relevant for a large number of people who suffer from depression.
"The current approach of a 'one-size-fits-all' medicine to treat depression is problematic. All currently available antidepressants target a particular type of neurotransmitter, but a third of patients do not respond to these drugs.
"We are now entering the era of 'personalised medicine' where we can tailor treatments to individual patients. This approach is starting to show success in treating cancers, and it's possible that in future we would use anti-inflammatory drugs in psychiatry for certain patients with depression."
The findings were published in the journal Molecular Psychiatry.