Does depression give us evolutionary advantage?

Depression Awareness Week, held this year from 22-28 April, aims to raise awareness of depression and to end the stigma attached to it. For the estimated one in five people in the UK and 120 million people worldwide who suffer from depression it can be a very isolating and debilitating condition. However, a controversial new theory has suggested depression actually offers an evolutionary advantage.

Although most people who suffer from depression would disagree, a number of evolutionary psychologists have suggested depression assisted our ancestors in fighting infection and may also help us re-evaluate our lives and decisions that lead to our depression.

The former proposal outlined in the journal Molecular Psychiatry highlights the finding that people who are depressed tend to have higher levels of inflammation or an overactivated immune system regardless of whether they are fighting infection or not. Depression has therefore developed as an adaptive response bound with physiological responses, to help fight and survive infection, allowing individuals to pass on their genes.

The latter proposal, on the other hand, hypothesises that people with depression use rumination as an adaptive strategy to solve painful issues, particularly given the finding that sad subjects were better judges of deception than happy ones. However it should be noted that much of this research has been criticised for its lack of generalisability.

Evolutionary psychologists hope by focusing on levels of inflammation we can better predict whether an individual will respond to treatment for depression and whether drugs to treat autoimmune diseases can be used effectively for treating depression, which doesn’t respond to therapy. Other researchers however argue that depression no longer serves any evolutionary advantage and remains a serious but highly treatable mental health problem.

If you are feeling depressed and would like to book an initial session with one of our experienced practitioners, please contact your local First Psychology centre on:

Edinburgh: 0131-668-1440, www.edinburghtherapy.co.uk
Glasgow: 0141-404-5411, www.glasgowpsychology.co.uk
Borders: 01896-800-400, www.borderspsychology.co.uk