Why are some people prone to depression? It may reflect the way they mull over events in their head.

Rumination – repeated dwelling on negative mood and events – is known to make people more susceptible to depression and likelier to be depressed for longer. Rumination can be helpful when people focus on specific details of a negative event, but in its abstract form (e.g. thinking 'why did this happen to me?') it can be psychologically damaging.

With new project grant funding, Dr Edward Watkins at the University of Exeter aims to find out why people prone to depression favour the abstract form of rumination, and whether they can be encouraged to shift to more positive forms.

When faced with a problem, people who have not been depressed typically adopt specific, concrete and detailed ways of thinking. Dr Watkins will test the theory that this shift to 'problem-solving' mode is disrupted in those prone to depression.

Image credit: Anna Sieveking, courtesy of the Medical Photographic Library