Autobiographical Memory Deficits in Depression Mirrored in Literature

‘Our civilisation is in a middle stage, scarcely beast, in that it is no longer guided by instinct, scarcely human in that it is not yet wholly guided by reason.’

This is the quotation Joseph LeDoux chose to cite at the beginning of his book The Emotional Brain. It comes from the novel Sister Carrie by Theodore Dreiser, and while the quotation well illustrates the sometimes enigmatic role emotion has in shaping our behaviour and thoughts, the novel itself and the literary movement of naturalism to which it belongs provides a metaphor for a more specific example of the influence emotion can have.

Naturalism is a movement within literature pioneered by Dreiser as well as other writers such as John Steinbeck and Upton Sinclair at the beginning of the twentieth century. Central to naturalism are characters not defined ethically, such as with Scrooge’s Christmas moral epiphany in Charles Dickens’ A Christmas Carol, but by their perseverance in navigating through an unremittingly grim industrial world. In Dreiser’s novel, the main character Carrie sacrifices her integrity to at first survive and then elevate herself socially against a backdrop of the harsh economic realities of industrialised Chicago. The relentless drudgery portrayed in naturalist writing provides a sharp contrast to the specific points of morality integral to characterisation elsewhere, and this can be seen to mirror the expression of autobiographical memory in people with and without depression.

Autobiographical memory is a form of episodic memory specifically for events in a person’s life. These are normally very specific and crisply defined, for example I remember when I got my first car, it was my 17^th birthday, and I was so excited... This is in contrast to the more opaque and over-generalised autobiographical memories that are commonly reported by people suffering from depression, for example I used to drive to work every day. This focus on category and repeated events in people with depression mirrors neatly with the themes of continuous and unrelenting endeavour within the depressing situations presented in naturalist novels.

While these patterns in autobiographical memory have been shown to be symptomatic of depression, recently published research by Willem Kuyken and Tim Dalgleish adds to evidence indicating over-generalisation in autobiographical memory may provide a risk factor for the development of depression in young people. The paper reports two studies which show well established risk factors for depression correlate with the generation of categorical autobiographical memories in response to negative cues in young people between the ages of 14 and 18.

In their first study, the authors report that higher scores on the personality dimension of neuroticism, a known risk factor for depression, correlated with over-generalised autobiographical memories. This, however, was largely mediated by depressive symptomology assessed using the Beck Depression Inventory. The second study provided more concrete evidence for a direct link between risk factors for depression and over-generalised autobiographical memories. They used two samples of previously depressed young people and never depressed young people, utilising the fact that depression has high levels of recurrence, meaning that having previously suffered from depression provides a significant risk factor for depression. Using structured interviews rather than written questionnaires as in the first study, it transpired that the young people who were previously depressed where more likely to report categorical autobiographical memories in response to negative cues.

Taken together, these findings suggest young people at risk of depression display autobiographical memory deficits in response to negative, but not positive cues. This is important as it suggests one intuitive explanation for this pattern of memory effects associated with depression, as it may be blocking recall of specific memories serves to protect against the elicitation of damaging negative associations.

Whilst this poses many questions for the future, not least how effective teaching strategies for cognitive control and emotional regulation might be as clinical interventions, it seems clear that over-generalisation is a key component of depression, something reflected in literature.

Kuyken W, & Dalgleish T (2011). Overgeneral autobiographical memory in adolescents at risk for depression. Memory, 1-10 PMID: 21400355