Abnormal Psychology Studies for Paper 2

What is prevalence in abnormal psychology?

The proportion of individuals in a population who have a specific disorder at a given time.

What was the aim of Caspi et al. (2003)?

To investigate whether the 5‑HTT gene moderates the effect of stressful life events on depression.

What was the procedure of Caspi et al.?

Longitudinal study of 1,000+ New Zealand participants. Participants grouped by 5‑HTT alleles (s/s, s/l, l/l) and assessed for stressful life events and depressive symptoms between the ages of 21 to 26.

What were the findings of Caspi et al.?

Individuals with one or two short alleles were more likely to develop depression after stressful life events than those with two long alleles.

How does Caspi et al. explain prevalence rates of MDD?

Genetic vulnerability helps explain why some individuals or populations have higher rates of depression than others.

What model does Caspi et al. support?

The diathesis–stress model.

What is the diathesis–stress model?

It explains mental disorders as resulting from an interaction between a pre-existing vulnerability (genetics or early trauma) and environmental stressors (like abuse).

One strength of Caspi et al.?

Large, longitudinal sample increases reliability and predictive validity.

One limitation of Caspi et al.?

Correlational; does not explain cultural or gender differences in prevalence.

What was the aim of Becker et al. (2002)?

To investigate the impact of Western television on eating attitudes and behaviors in Fijian adolescent girls.

What was the procedure of Becker et al.?

A natural experiment; compared Fijian girls in 1995 (before TV) and 1998 (after TV). Used EAT‑26 questionnaires and interviews afterwards to question eating habits and diets.

What were the findings of Becker et al.?

After the introduction of Western TV, there was an increase in dieting, body dissatisfaction, and purging behaviors.

How is Becker et al. relevant to prevalence of depression?

Body dissatisfaction and disordered eating are strongly comorbid with depression, suggesting cultural exposure can increase prevalence.

One strength of Becker et al.?

High ecological validity; demonstrates cultural influence on abnormal behavior.

One limitation of Becker et al.?

Correlational and does not directly measure depression. Cultural factors are complex and multifaceted.

How do Caspi et al. and Becker et al. complement each other?

Caspi explains individual biological vulnerability, while Becker explains population‑level cultural influences on prevalence.

Why is a single‑factor explanation of prevalence insufficient?

Prevalence results from the interaction of biological, psychological, and sociocultural factors.

What is the overall conclusion for this ERQ?

Prevalence rates of MDD vary due to both genetic vulnerability and sociocultural influences.