Depression may distort views of the past

London, Aug 16: While it is known that depression makes sufferers see the present and the future as sad, new research has shown it also casts a long shadow over people's memories of the past.

Depressed people have a peculiar view of the past -- rather than glorifying the 'good old days', they project their generally bleak outlook on to past events, according to the study published in the journal Clinical Psychological Science.

"Depression is not only associated with a negative view of the world, the self and the future, but we now know with a negative view of the past," said one of the study authors Hartmut Blank from the University of Portsmouth in England.

The study establishes the first clear link between depression and hindsight bias, or a distorted view of the past.

"Everyone is susceptible to hindsight bias, but it takes on a very specific form in depression. While non-depressed people tend to show hindsight bias for positive events but not negative events, people with depression show the reverse pattern," Blank said.

The researchers tested over 100 university students, about half of whom suffered from mild to severe depression.

They were asked to imagine themselves in a variety of everyday scenarios with positive or negative outcomes.

For each scenario, the researchers then collected measures of hindsight bias.

The results showed that with increasing severity of depression, a specific hindsight bias pattern emerged -- exaggerated foreseeability and inevitability of negative event outcomes, as well as a tendency to misremember initial expectations in line with negative outcomes.