Abnormal Psychology Study

What are 2 studies that talk about the biological prevalence of depression

1. Caspi et al. (2003)

2. Kendler et al. (2006)

What are 2 studies that talk about the biological etiology of depression

1. Caspi et al. (2003)

2. Kendler et al. (2006)

aim of Caspi et al. (2003)

To investigate the role of the 5-HTT gene in depression, particularly whether genetic differences influence vulnerability to stress-induced depression.

procedure of Caspi et al. (2003)

• Longitudinal study of 847 New Zealand participants from birth to age 26.

• Participants were genetically tested for the short or long version of the 5-HTT gene (linked to serotonin regulation).

• They were assessed for life stressors between ages 21-26 (e.g., job loss, relationship issues).

• Depression symptoms were measured using structured interviews and compared across different genetic groups.

results of Caspi et al. (2003)

• Participants with the short version of 5-HTT were more likely to develop depression after stressful life events.

• Those with the long version were less vulnerable to stress-related depression.

• Simply having the short allele didn’t cause depression, but stress in combination with genetics increased risk.

conclusion Caspi et al. (2003)

• Gene-environment interaction affects depression risk.

• Having the short 5-HTT allele increases vulnerability but does not directly cause depression.

strengths of Caspi et al. (2003)

✅ Large sample size → Increases reliability.
✅ Real-life application → Helps explain why some people develop depression after stress while others don’t.

limitation of Caspi et al. (2003)

❌ Correlation, not causation → Cannot prove that the gene alone causes depression.
❌ Self-reported stress → Participants’ memory of life stressors may be biased.

ethical consideration of Caspi et al. (2003)

✔ Genetic confidentiality → Participants’ genetic information was protected.
✖ Psychological distress → Knowing one’s genetic risk for depression could cause anxiety.

evaluation of Caspi et al. (2003) in term of epidology

Research method of Caspi et al. (2003)

Quasi-experiment (Naturally occurring genetic differences)

aim of Kendler et al. (2006)

To investigate the heritability of Major Depressive Disorder (MDD) using twin studies.

procedure of Kendler et al. (2006)

• 42,000+ Swedish twins (both identical and fraternal) were studied.

• Interviews assessed whether they had experienced depression.

• Comparison between identical (MZ) and fraternal (DZ) twins was used to estimate genetic influence.

results of Kendler et al. (2006)

• Concordance rate for MDD:

  • Identical twins (MZ): 38%

  • Fraternal twins (DZ): 14%

• Shows that genetics play a role, but not 100%, indicating environmental factors also contribute.

conclsuion of Kendler et al. (2006)

• Depression is moderately heritable (~38%).

• Environmental factors also play a significant role in developing MDD.

strength of Kendler et al. (2006)

✅ Large sample size → Increases generalizability.
✅ Twin study design → Helps separate genetic and environmental influences.

limitation of Kendler et al. (2006)

❌ Cannot control for shared environments → Twins may have similar life experiences.
❌ Self-reported depression → Potential bias in participants’ memory.

ethical considerations of Kendler et al. (2006)

✔ Confidentiality protected → Twin identities remained private.
✖ Potential distress → Learning about genetic predisposition could cause anxiety.

evaulation of Kendler et al. (2006) in terms of prevalence

evaulation of Kendler et al. (2006) in terms of epidology

research method of Kendler et al. (2006)

Correlational Study: Twin study, no manipulation

2 studies that talk about cognitive etiology of depression

1. Alloy et al. (1999)

2. Caseras et al. (2007)

aim of Alloy et al. (1999)

To investigate whether negative cognitive styles in young adults predict depression.

procedure of Alloy et al. (1999)

• Longitudinal study of young adults over 5 years.

• Participants were classified into:

  • High-risk group (had a pessimistic, negative thinking style).

  • Low-risk group (had a positive thinking style).

• Researchers tracked them for signs of depression over time.

results of Alloy et al. (1999)

• High-risk individuals were far more likely to develop depression than low-risk individuals.

• Suggests that negative thinking patterns contribute to MDD.

conclusion of Alloy et al. (1999)

Cognitive vulnerability increases the risk of developing depression.

strenghts of Alloy et al. (1999)

✅ Longitudinal design → Shows how cognitive styles predict depression over time.
✅ Real-world application → Helps in developing cognitive-based therapies.

limitations of Alloy et al. (1999)

❌ Self-report bias → Thinking patterns were self-reported.
❌ Correlation, not causation → Negative thinking might be a result of depression, not a cause.

ethical considerations of Alloy et al. (1999)

✔ Informed consent obtained → Participants knew the risks.
✖ Potential psychological distress → Discussing negative thoughts might have triggered depressive symptoms.

evaluation of Alloy et al. (1999) in relation to etiology

evaluation of Alloy et al. (1999) in relation to prevalence

2 studies that talk about the cognitive prevalence of depression

1. Alloy et al. (1999)

2. Caseras et al. (2007)

evaluation of Caspi et al. (2003) in term of prevalence

aim of Caseras et al. (2007)

To investigate whether people with depressive symptoms have an attentional bias toward negative stimuli.

procedure of Caseras et al. (2007)

• Participants looked at images on a screen (some negative, some neutral).

• Eye-tracking technology was used to measure how long they looked at each image.

• Depressive symptoms were measured through a questionnaire.

results of Caseras et al. (2007)

• Participants with depressive symptoms looked longer at negative images.

• Suggests a cognitive bias toward negativity in those prone to depression.

conclusion of Caseras et al. (2007)

• Attentional biases contribute to maintaining depression by reinforcing negative thoughts.

strength of Caseras et al. (2007)

✅ Objective measurement (eye-tracking) → Reduces self-report bias.
✅ Supports Beck’s cognitive model → Negative attention patterns reinforce depression.

limitation of Caseras et al. (2007)

❌ Lab setting → May not reflect real-life thought patterns.
❌ Correlation, not causation → Does not prove bias causes depression.

ethical consideration of Caseras et al. (2007)

✔ Debriefing provided → Researchers ensured participants didn’t leave feeling worse.
✖ Negative stimuli exposure → Could have triggered distress.

evaluation of Caseras et al. (2007) in relation to etiology

evaluate Caseras et al. (2007) in relation to prevalence

2 studies that talk about the sociocultural etiology of depression

2 studies that talk about the sociocultural prevalence of depression

1. Brown & Harris (1978)

2. Kivelä et al. (1996)

aim of kivelä et al. (1996)

To investigate how social and cultural factors influence the development of depression in elderly individuals.

procedure of kivelä et al. (1996)

• Longitudinal study conducted in Finland with 1,600+ elderly participants (60+ years old).

• Participants were interviewed and assessed for depression using diagnostic criteria.

• Researchers collected data on social factors (e.g., living situation, marital status, social support, health issues).

• Follow-ups were conducted years later to see who had developed depression.

results of kivelä et al. (1996)

• Higher risk of depression was found in elderly people who:

  • Lived alone or had poor social relationships.

  • Had chronic illnesses or disabilities.

  • Had experienced major life stressors (e.g., loss of a spouse).

• Good social support and strong family connections were protective factors.

conclsuion of kivelä et al. (1996)

• Social isolation, poor health, and major life stressors increase depression risk in older adults.

• Cultural and social factors play a crucial role in depression prevalence.

strengths of kivelä et al. (1996)

✅ Longitudinal design → Shows how social factors predict depression over time.
✅ Large, representative sample → Improves generalizability to elderly populations.

limitation of kivelä et al. (1996)

❌ Only studied Finnish elderly → Findings may not generalize to other cultures.
❌ Self-report bias → Depression symptoms and social factors were self-reported.

ethical consideration of kivelä et al. (1996)

✔ Informed consent obtained → Participants voluntarily took part in the study.
✖ Psychological distress → Discussing personal losses or loneliness may have been upsetting.

evaluation of kivelä et al. (1996) in relation to epidology

evaluation of kivelä et al. (1996) in relation to precevalence

evaluation of kivelä et al. (1996) in the variation of culture in prevelnce rates

aim of Brown & Harris (1978)

To investigate how social factors (like life stress) contribute to depression in women.

procedure of Brown & Harris (1978)

• 458 women in London were interviewed about life events and depression.

• Researchers identified factors that increased vulnerability to depression.

results of Brown & Harris (1978)

• Severe life events (e.g., loss of a loved one, financial hardship) increased depression risk.

• Women with little social support were more vulnerable.

conclusion of Brown & Harris (1978)

Social stress is a major risk factor for depression.

strenght of Brown & Harris (1978)

✅ Ecological validity → Real-life stressors were studied.
✅ Explains gender differences → Shows why women have higher depression rates.

limitation of Brown & Harris (1978)

❌ Self-report bias → Participants may have misremembered life events.
❌ Only women studied → Cannot generalize to men.

ethical consideration of Brown & Harris (1978)

✔ Confidentiality maintained → Sensitive life histories protected.
✖ Psychological distress → Discussing past traumas could be upsetting.

evaluation of Brown & Harris (1978) in relation to etiology

evaluation of Brown & Harris (1978) in relation to prevalence

what are 2 studies that talk about the cultural variation of prevelance rates

1. Kivelä et al. (1996)

2. Kleinman (1982)

aim of Kleinman (1982)

To investigate how Major Depressive Disorder (MDD) presents differently in Chinese and Western cultures, particularly whether depression is somatized (expressed through physical symptoms) in Chinese patients.

procedure of Kleinman (1982)

• Conducted a clinical observation study on 100 Chinese psychiatric patients in China diagnosed with neurasthenia (a condition with symptoms of fatigue, headaches, and insomnia).

• Assessed whether their symptoms aligned with Western definitions of MDD based on the DSM criteria.

• Compared symptom expression in Chinese patients vs. Western patients diagnosed with MDD.

results of Kleinman (1982)

• 87% of patients diagnosed with neurasthenia met the DSM criteria for MDD, but their symptoms were primarily somatic (physical), such as fatigue, headaches, dizziness, and insomnia.

• Few patients reported affective symptoms (sadness, guilt, or worthlessness), which are typical of MDD in Western cultures.

• Suggested that cultural norms shape symptom expression—in China, emotional distress might be stigmatized, leading individuals to report physical rather than emotional symptoms.

conclusion of Kleinman (1982)

• Depression is universal, but its expression varies across cultures.

• In Western cultures, depression is psychologized (emphasizing mood and cognitive symptoms), while in China, it is somatized (expressed through physical complaints).

• Highlights the need for culturally sensitive diagnostic criteria to avoid misdiagnosing or underdiagnosing MDD in non-Western populations.

strength of Kleinman (1982)

• Cross-Cultural Insight:

  • Provides valuable evidence for cultural differences in mental health and highlights the limitations of using Western diagnostic tools globally.

• Clinical Relevance:

  • Supports the importance of culturally adapted treatments and diagnostic criteria, helping psychiatrists avoid misdiagnosis of MDD in different cultural groups.

limitation of Kleinman (1982)

• Small & Unrepresentative Sample:

  • Only studied 100 patients in China, making it difficult to generalize findings to all Chinese individuals or other non-Western cultures.

• Lacks Control Group (Comparative Data):

  • The study did not directly compare Western patients to Chinese patients under identical conditions, making it unclear if differences are due to culture or other factors (e.g., different diagnostic practices).

ethical considerations of Kleinman (1982)

✅ Good (Respect for Participants’ Culture):

• The study respected cultural differences rather than imposing Western assumptions about mental health.
  ❌ Bad (Potential Stigma & Misdiagnosis):

• By emphasizing somatization, there is a risk that Chinese individuals might not receive proper psychological treatment, reinforcing stigma against discussing mental health openly.

evaluation of Kleinman (1982) in relation the the cultural variation of prevalence rates

• Kleinman (1982) demonstrates that cultural factors influence how MDD is expressed and diagnosed.

• Western diagnostic tools (DSM, ICD) may not fully capture depression in non-Western populations, leading to underdiagnosis.

• Supports the need for culturally sensitive approaches in psychology to improve diagnosis, treatment, and understanding of mental health across different cultures.