A pessimistic view of the future may not be the result of depression but the cause of it.

That is the conclusion of research by Ann Marie Roepke and Professor Martin Seligman from the University of Pennsylvania published today, Friday 11 June 2015, in the British Journal of Clinical Psychology.

The two researchers carried out a review of the literature on depression and 'prospection' -- the mental representation of possible futures. From it they propose that three kinds of faulty prospection can drive depression.

These are:

poor generation of possible futures

poor evaluation of possible future

negative beliefs about the future

The researchers also proposed that depressed mood and poor functioning may in turn maintain faulty prospection and so feed a vicious cycle.

They suggest that faulty prospection can be treated by strategies drawn from cognitive behavioural therapy (CBT), a form of 'talk therapy' that tackles patterns of thinking that can lead to problems with mood or behaviour.

The authors say: "Prospection belongs front and centre in the study of depression. Laboratory studies are needed to confirm that faulty prospection does drive depression and to help us determine how prospection can be improved. We hope clinical scientists will invest in research on prospection to shed more light on a crucial and underappreciated process that may underlie much more than depression.

"An understanding of how prospection shapes psychopathology may enable researchers to create more effective treatments and help distressed individuals to create brighter futures."

The researchers suggest some aspects future research might explore. This includes establishing what helpful prospection looks like; determining how much time people with depression spend thinking about the past, present and future -- and how much they should; and clinical trials to see if CBT aimed particularly at prospection is more helpful to people with depression than conventional CBT."