Abnormal Psychology Flashcards
(7 cards)
Biological explanations for MDD (gene)
Caspi et al. (2003)
Aim: To examine the link between alleles of the 5-HTT gene and depression.
Procedure:Participants were divided into three groups based on their 5-HTT alleles: group 1 had two short alleles; group 2 had one short and one long allele; group 3 had two long alleles. The mutation of the 5-HTT gene has the shorter alleles. Participants filled in a “stressful life event” questionnaire which asked them about the frequency of different stressful events between the ages 21-26. They were also assessed for depression.
Results: People who had inherited one or more short versions of the allele demonstrated more symptoms of depression and suicidal ideation in response to stressful life events. The effect was strongest for those with three or more stressful life events.
Conclusion: Simply inheriting the gene was not enough to lead to depression, but the genes interacting with stressful life events increased one’s likelihood of developing depression.
Biological explanations for MDD (twin study)
McGuffin et al. (1996)
Aim: To investigate concordance rates for MDD in MZ and DZ twins.
Procedure: Twin probands registered with MDD were identified. Their same-sex twin siblings were used as comparison participants. Blind researchers assessed the twins via tests and interviews and also used their medical records.
Results: MZ twins showed a much higher concordance rate for MDD, compared with DZ twins. Shorter periods of depression in one MZ twin were matched by similar depression in their twin sibling.
Conclusion: MDD may be highly heritable rather than a product of environmental factors. Short-term MDD in one MZ twin appears to increase the probability of their MZ twin sibling also developing MDD, reinforcing the idea that depression is genetic.
Cognitive explanations for MDD (EMS).
Riso et al. (2006)
Aim: To investigate the extent to which Early Maladaptive Schemas (EMS) are stable over time and to investigate the role of EMS in the experience of MDD.
Procedure: Patients diagnosed with MDD completed a questionnaire measuring 16 EMS, which included emotional deprivation, vulnerability to harm and failure to thrive. The severity of their depression was measured at the start, and they completed a follow-up questionnaire 2.5 to 5 years later.
Results: Correlations between EMS scores at the baseline and the follow-up were statistically relevant, and MDD had not improved for participants with high EMS scores.
Conclusion: EMS appear to be stable and long-lasting and play a key role in MDD into adulthood.
Cognitive explanations for MDD (cognitive distortions).
Beck et al (1974)
Aim: To investigate the role of cognitive distortions in patients with MDD.
Procedure: Clinical interviews were conducted with patients with MDD and a control group of non-depressed patients. Patients reported their feelings and thoughts during sessions, and some kept diaries. Therapists noted what both groups said for comparison.
Results: The verbalisations of MDD patients showed a high number of references to themes like anticipation of harm, fear of rejection, and a self-blaming bias. These cognitive distortions appeared automatic and persistent, with patients believing in them.
Conclusion: Patients with MDD suffer from cognitive distortions that impair their thinking and rationality. These distortions seemed specific to MDD and not other disorders like anxiety.
Sociocultural explanation for MDD (vulnerability model).
Brown and Harris (1978)
Aim: To determine the role of environmental factors in the onset of depression in women.
Procedure: Researchers carried out a survey on women. The participants were asked questions regarding whether they had suffered any episodes of depression in the past year, and were asked to describe any difficult life events.
Results: Of the women who became depressed, nearly all of them had experienced stressful life events, like the loss of a job. By contrast, 30% of the women who did not become depressed also experienced stressful life events. Furthermore, social class played an important role in depression risk, especially for women with children. Lower-class women with children were four times as likely to develop depression as middle-class women with children
Conclusion: Social factors - such as stressful life events - play a significant role in depression. Lower-class women with children are particularly at risk, as they may be more likely to face financial problems and other stressful situations.
Sociocultural explanations for MDD (social support).
Hays, Turner and Coates (1992)
Aim: To investigate whether a lack of social support may lead to depression and have an effect on one’s health.
Procedure: Gay men were interviewed and tested for AIDS symptoms, they could ask for their HIV status if they wanted. Self-response questionnaires about psychosocial factors were carried out twice during the study to rate how often participants experienced psychological symptoms. This included questions about HIV status awareness. A social support scale rated satisfaction with informational, practical, and emotional support.
Results and conclusion: Satisfaction with emotional, practical, and informational types of social support was inversely correlated with depression. The more satisfied they were with the support, the less depressed they were. The researchers found that gay men diagnosed with HIV were more likely to develop depression if they are rejected by family members.
Prevalence rates
Abdoli et al. (2022)
Aim: To investigate the global prevalence of MDD in the elderly.
Procedure: A meta-analysis of over 18 thousand participants from 20 different studies investigating MDD in elderly populations was conducted. The participants constituted a cross-cultural sample with studies taken from countries and cultures worldwide.
Results: The global provenance of MDD in elderly populations was around 13% , significantly higher than the global prevalence of depression is estimated at 5%. The difference of prevalence rate for elderly women and men was not statistically significant.
Conclusion: MDD has high prevalence rates globally amongst the elderly so this finding should be used to implement social support as an intervention to mitigate the negative impact of MDD on older people’s mental health.
