Cognitive Etiology of Major Depressive Disorder

Etiology

Etiology refers to the study of the origins or causes of a disorder. In psychology, it examines the biological, cognitive, and sociocultural factors that lead to mental health conditions.

Major Depressive Disorder (MDD)

MDD is a mental disorder characterized by persistent sadness, loss of interest or pleasure, fatigue, feelings of worthlessness or guilt, and sometimes suicidal thoughts, lasting for at least two weeks.

Cognitive etiology of depression

It refers to the idea that depression is caused by maladaptive or dysfunctional thinking patterns, such as negative beliefs and cognitive distortions.

Beck's Cognitive Theory of Depression

A theory suggesting that depression results from the cognitive triad: negative thoughts about the self, the world, and the future, formed through negative schemas and maintained by cognitive distortions.

Cognitive triad

A set of three types of automatic negative thoughts: about the self ('I am worthless'), the world ('The world is unfair'), and the future ('Nothing will ever improve').

Cognitive schemas

Mental frameworks that influence how individuals interpret information; in depression, these are negative and often formed through early life experiences.

Cognitive distortions

Faulty or biased ways of thinking that reinforce negative schemas, including all-or-nothing thinking, catastrophizing, and overgeneralization.

Automatic negative thoughts (ANTs)

Immediate, habitual thoughts that are negative and irrational, contributing to and maintaining depressive symptoms.

Beck (1974) Aim

To investigate the role of cognitive distortions in patients with MDD.

Strengths of Beck (1974)

High ecological validity (real-world data that is rich), led to CBT development, supported by clinical experience.

Limitations of Beck (1974)

Not experimental (no cause-effect), based on subjective observations, lacks quantitative data, small sample size

Alloy et al. (1999) Aim

To determine whether cognitive styles/thinking patterns could influence onset of depression

Alloy 1999 participants

Non-depressed college freshmen with no other diagnosed disorders. Half of the sample had a history of clinical depression; the other half did not. The students with a history of clinical depression demonstrated no symptoms at the beginning of the study.

Strengths of Alloy et al. (1999)

Longitudinal design, strong support for cognitive causation, real-world relevance.

Limitations of Alloy et al. (1999)

Only American college students (limited generalizability), correlational (not true causality), no other factors considered

Support for cognitive etiology

Beck provides a theoretical framework based on clinical data, while Alloy et al. offer empirical support that negative thinking precedes depression.

Criticisms of cognitive etiology

It may ignore biological and sociocultural factors, does not fully explain causality, and may place too much emphasis on individual responsibility.

Biological evidence challenging cognitive etiology

Kendler et al. (2006) showed genetic heritability of depression, suggesting a strong biological basis.

Sociocultural evidence challenging cognitive etiology

Brown and Harris (1978) showed that social factors like stress and gender roles contribute significantly to depression risk.

Holistic approach to explaining depression

The biopsychosocial model, which integrates cognitive, biological, and sociocultural factors for a more complete understanding.

Strength of cognitive theories of depression

They offer strong explanatory power and led to effective treatments like Cognitive Behavioral Therapy (CBT).

Limitation of cognitive theories

They may neglect other influences (biological, environmental) and often rely on correlational evidence.

Conclusion on cognitive etiology of depression

Cognitive theories explain depression to a large extent, but are best understood when combined with biological and sociocultural approaches (biopsychosocial model).

Beck 1974 Participants

50 patients with MDD and control group of 30 participants (who underwent psychotherapy)

Samples were matched in terms of demographics

Beck 1974 procedure

Clinical interviews were conducted with both groups

The participants were asked to report on their feelings before the session and to spontaneously contribute their thoughts and feelings throughout the session

Some of the patients logged their thoughts in diaries or journals which they brought to the sessions

The therapists kept note of what both groups of patients said during the sessions which then formed the basis of their comparison of the two groups

Beck 1974 results

There were distinct dierences between the verbalisations and conversational content of the MDD patients compared to the control group patients

The content of the MDD patients9 verbalisations included a high number of references to the following themes:

High anticipation of physical harm and danger

Fear of becoming ill High anticipation of being rejected or attacked by others

A self-blaming bias e.g. feeling that others were more attractive, successful and content than they were and that these failures were due to their own ineptitude and inferiority

A negative self-schema in their beliefs that they were unlovable, that no-one would want to be with them

These cognitive distortions appeared to be beyond the control of the MDD patients, being automatic and persistent

The MDD patients expressed belief in their cognitive distortions, they found the distortions plausible and inevitable

Beck 1974 conclusions

Patients with MDD suer from cognitive distortions which cloud their thinking and impede logic and rationality

The cognitive distortions experienced by the MDD patients appeared to only relate to MDD and not to other disorders such as anxiety

Alloy 1999 procedure

To begin, the students were given a test to measure their cognitive style. The students were identified as either High Risk (HR) or Low Risk (LR) for depression based on their thinking patterns. The researchers carried out follow-up assessments every 6 weeks for 2.5 years and then every 4 months for an additional three years. The study was based on a combination of questionnaires and structured interviews to identify stressful life events, cognitive style and symptoms of depression.

Alloy 1999 results

After 6 years the researchers that cognitively high risk patients, negative group, had a 17% lifetime prevalence than low risk patients, positive group, who had only 1% lifetime prevalence of major depression. The results show that the participants in the high risk group were more likely to show symptoms of depression.

Alloy 1999 conclusions

Cognitive styles can influence depression and can be used to predict future illness