Exercise does appear to reduce symptoms of depression, new research suggests.

Around 120 million people suffer from depression worldwide, including 280,000 people in Ireland. Antidepressant medication and psychological therapies are both seen as effective treatments for the condition.

However, medication can cause unwelcome side-effects and not everybody has access to psychological therapies.

Exercise is also recommended for people with depression as it can change the hormone levels affecting mood and can act as a distraction from negative thoughts.

However previous research has found only limited evidence linking exercise with less depression.

As more trials in this area have recently been carried out, Scottish researchers decided to look into this further. They carried out a review of 39 trials involving over 2,300 people with depression.

In 35 of the trials, the researchers found that exercise had a moderate benefit when it came to depression. Furthermore a few small trials found that exercise was as effective as psychological therapy and taking antidepressants.

"Our review suggested that exercise might have a moderate effect on depression. We can't tell from currently available evidence which kinds of exercise regimes are most effective or whether the benefits continue after a patient stops their exercise programme," the researchers from the University of Edinburgh explained.

However, they acknowledged that the link between exercise and depression was weaker when they focused on six high quality trials.

"When we looked only at those trials that we considered to be high quality, the effect of exercise on depression was small and not statistically significant. The evidence base would be strengthened by further large scale, high quality studies," the team added.

Details of these findings are published in the Cochrane Database of Systematic Reviews 2013.

For more information on depression, see our Depression Clinic here