Research has highlighted links between a lack of Omega-3 fatty acids in a diet and a higher risk of depression.

Countries with a fish-rich diet such as Japan have unusually low rates of seasonal affective disorder, where sufferers experience symptoms of depression in the winter months.

Other studies have shown that people suffering with severe depression have lower than normal levels of the Omega-3 fats EPA and DHA.

Mums who eat a lot of fish also seem to be much less likely to suffer from post-natal depression, and keeping Omega-3 levels topped up can help people deal better with stress.