Cognitive science pioneer Aaron Beck revolutionized the scientific investigation of depression, and his subsequent research has elucidated biological mechanisms that underpin some cognitive features of the disorder. In a new article published in Clinical Psychological Science, Beck and colleague Keith Bredemeier of the University of Pennsylvania aim to integrate these findings to produce a coherent and comprehensive theoretical account of depression.
With their unified model, Beck, an APS James McKeen Cattell Fellow, and Bredemeier draw on findings spanning various levels of analysis and multiple disciplines — including clinical, cognitive, biological, and evolutionary approaches — to provide a broad framework that accounts for the symptomatology of depression and its natural course, from predisposition to recovery.
“All of the findings related to depression can be joined together to provide a comprehensive model of the disorder that explains its puzzling features,” they write.
The unified model is based on the premise that depression represents an adaptation to the perceived loss of essential human resources that provide access to the necessities of life — including the loss of a family member, a romantic partner, or a peer group. To individuals who are at greater risk for severe depression because of specific genetic or environmental factors, this loss is more likely to be viewed as devastating and insurmountable.
Heightened reactivity to stress and entrenched cognitive biases lead these at-risk individuals to espouse negative beliefs about the self, the world, and the future — a combination that Beck has termed the “negative cognitive triad.” When activated (e.g., by stressful life events), these beliefs trigger consistent emotions, such as sadness, anhedonia, and guilt, as well as behavioral and physiological responses, such as withdrawal, inactivity, and loss of appetite.
The overarching function of this so-called “depression program,” the researchers say, is to promote the conservation of energy in the face of the perceived loss of resources.
Over time, the depression program reinforces the negative beliefs that put the individuals at risk for depression in the first place. Importantly, it can be stopped when the vital resources are restored, either because new information emerges that “corrects” the negative biases or because the situation itself changes. External factors such as support from friends and family, guidance from a psychotherapist, and biological treatment (e.g., medication) can aid in stopping the cycle of depression.
“Our model suggests that any intervention that targets key predisposing, precipitating, or resilience factors can reduce risk or alleviate symptoms,” Beck and Bredemeier explain.
The researchers note that their unified model of depression is tentative, and they are hoping that scientists will systematically evaluate and refine the model based on new findings.
“We hope that this model will motivate further development of new (and more integrative) approaches for treating or preventing depression,” they write.
Beck, A. T., & Bredemeier, K. (2016). A unified model of depression: Integrating clinical, cognitive, biological, and evolutionary perspectives. Clinical Psychological Science. Advance online publication. doi:10.1177/2167702616628523