Depression: How People ‘Update’ Beliefs About Future Life Events Differently
The optimism bias is an interesting bias that has long been studied. The optimism bias states that a person believes that they are less at risk of experiencing a negative event compared to others.
This bias remains stable even when people are offered clear evidence to the contrary, the bias can permeate all aspects of life such as outlook on finance, crime, mental health and work.
A study recently published in Psychological Medicine journal aimed to consider how outlook biases differed in people with depression and hypothesised that:
unlike healthy individuals, depressed individuals are characterized by a breakdown of a selective updating bias in response to information about their future.
That is to say that the researchers thought individuals suffering from depression where less likely to be optimistic given desirable information about their future life events.
The study recruited 2 groups of participants, the first group was the ‘healthy’ control group which consisted of participants with no psychiatric disorders. The second group consisted of participants with a diagnosis of a major depressive disorder.
The researchers used a list of seventy short descriptions of negative life events in order to establish the participants beliefs about the life events once they had been presented with the frequency of that event occurring at least once to a person.
The participants estimated the frequency of the event ‘happening’ or ‘not happening’ to themselves.
The researchers from the Freie Universität Berlin, Germany were able to identify differences between the two groups:
We show an absence of optimistic bias in belief updating in depressed individuals and this absence correlated with their symptom severity.
Healthy individuals updated their beliefs more when presented with desirable information about the likelihood of experiencing adverse life events relative to undesirable information
It was discussed how these findings matched existing knowledge:
In accord with cognitive theories of depression, depressed individuals exhibited a pessimistic view of the future, evident in their inflated estimates of the probabilities of experiencing adverse events relative to controls and to the average probabilities of these events in the population.
The authors concluded that depressed individuals may benefit from therapy approaches that focus on inducing positive biases and cognitive bias modification such as those utilised by positive psychology interventions.
Korn CW, Sharot T, Walter H, Heekeren HR, & Dolan RJ (2014). Depression is related to an absence of optimistically biased belief updating about future life events. Psychological medicine, 44 (3), 579-92 PMID: 23672737