Depression A2 Psychology (sourced from Emma Rudd)

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  • Created by: Hannah
  • Created on: 27-06-10 12:07


Definition = Depression is an affective mood disorder, with prolonged disturbances to mood and emotions.

Clinical Characteristics

Unipolar Disorder (Major Depression) is characterised by;

  • Lowering of mood – individual feels intensely unhappy and empty

  • Lack of motivation, drive, determination and initiative

  • Negative views of themselves and the world

  • Feelings of anxiety

  • Disturbances to sleep and appetite

  • Changes in menstrual cycle

Bipolar Disorder (Manic Depression) includes

  • Both manic and depressive episodes

  • Delusions

  • Hallucinations (Auditory and visual)

  • Easily distracted

  • Rapid speech, more talkative

Other Symptoms

  • Lack of motivation

  • Lack of physical energy

  • Low self esteem

  • Isolation

  • Social Withdrawal

  • Crying

  • Not wanting to eat/go out/ see people

  • Iritic emotions

  • Insomnia

Biological Explanations of Depression

  1. Genetics

The medical approach argues that psychological problems have a physical cause. It argues that genes are one of these causes. From this view people with a particular genetic makeup have a predisposition to depression.

Supporting Evidence

  • Twin Studies – Allen

Allen looked at unipolar (major depression)and found

  • For (MZ) identical twins there was a concordance rate of 49%

  • For (DZ) non-identical twins the concordance rate was just 11%

He then looked at Bipolar (manic depression) and found

  • For identical / MZ twins there was a 72% concordance rate

  • For non identical / DZ twins the concordance rate was just 14%

The fact that the concordance rates were different for the unipolar disorder and the bipolar disorder suggests that if genetic factors are the cause then they are different for the 2 disorders.

Evaluation of Genetic Explanation

  • Twin studies can provide convincing evidence to support the role of genetic factors

  • Twins share the same environment, therefore cannot separate the influences.

  • If it were completely biological concordance rate for identical would be 100%

  • Produces a bias sample most people aren’t twins so generalisation is difficult

  • Difficult to obtain a sample, twins who suffer and are willing to take part

  • Ethics – Some argue that research into genetics and behaviour will influence some to ‘iron out’ what they consider undesirable traits. Who decides what is desirable or undesirable?

  • Adoption Studies – These are studies that compare people who have been adopted with their biological and adoptive parents

  • Harrington et al (1993) found that biological relatives are more likely than adoptive relatives to have a similar diagnosis. - 20% of biological relatives compared with 5% of adoptive relatives

  • Wender et al (1986) found that biological relatives of unipolar sufferers were 8 times more likely to have had it themselves

Evaluation of Adoption Studies

  • Findings from adoption studies are unclear

  • There are relatively few adoption studies conducted

  1. Chromosomes

Studies have attempted to identify sequences of genes that appear to be inherited alone with the predisposition to develop depression.

  • Egeland et al researched the Amish community and found that

  • 4 extended families had a high predisposition for developing depression

  • From 81 people studied 14 were diagnosed with bipolar disorder.

  • The disorder appeared to be linked to chromosome 11


  • Findings haven’t been replicated. – This could suggest C11 doesn’t actually play a…



A very useful breakdown of depression studies - perfect for A2 students who study Depression under AQA(a).

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