Inherited Factors (Biological): 1) Genetic Predisposition (expression for Depression)

Studies: Nurnberger and Gershon (1982) on concordance rates in twin studies for depression.

Constitutional (biological) vulnerability

PSYCHIATRIC OUTCOME (Depression)

Neuromaturational Factors (Biological)1. Neurotransmitters 2. Hormones

Studies: Janowsky et. Al (1972), Delgado and Moreno (2000) on imbalances in neurotransmitters affecting depression.

More Evidence: Imbalances in hormone levels (cortisol and depression). Read about Cushing’s syndrome in depression.

Stress (Sociocultural Factors): 1) Severe life events and social status.Studies:Brown and Harris (1978) on social vulnerability of women in depression as well as the social vulnerability model.

Cognitive Factors:1. Irrational and Illogical thinking2. Cognitive distortions3. Negative thinking patterns

Studies: 1) Ellis (1962) on faulty conclusions/irrational believes leading to self-defeating

conclusions (depression). 2) Beck (1976) argues that when people have negative cognitive schemas they can interfere with information processing and lead to depressive feelings3) Alloy et. Al (1999) studied relationship between negative thinking and development of depression.

APPLIED WALKER-TESSNER MODEL FOR MAJOR DEPRESSIVE DISORDER