a) There are many characteristics of depression that needs to occur for at least 2 weeks to be diagnosed with the disorder. Appetite is usually reduced but can increase (comfort eating) and tend to be unhealthy. Sleep disturbances occur and sex drive is usually reduced. Auditory hallucinations may occur which often involve voices that are abusive and critical of the depressive. Depressives have slow, muddled thinking and difficulty in making decisions. Thinking is pessimistic, negative and, in severe cases, suicidal and there is also a reduced activity due to their lack of interest and energy. Depressives usually show social withdrawal and do not gain pleasure from social interaction.
b) There are 2 main explanations for depression, psychological and biological. An example of a biological explanation is genetic factors. A twin study by Allen in 1976 found for patients with unipolar depression the mean concordance rate was 40% for monozygotic twins. For those with bipolar depression the mean concordance rate was 14% for dizygotic twins. This suggests that monozygotic twins whose sibling suffers unipolar are more likely to suffer from depression themselves. However Bertelsen, Harvald and Hauge (1977) found that the concordance rate for major depression (unipolar) was 59% for monozygotic twins and 30% for dizygotic twins. The concordance rate for bipolar disorder was 80%for monozygotic twins and 16% for dizygotic twins. This suggests bipolar disorder is more likely to be genetically inherited for monozygotic twins, and unipolar more likely for dizygotic twins. Gershon (1990) reviewed the findings from a number of family studies and found that depression runs in families. The rate of depression was two to three times higher in the first degree relatives of depressives compared to the general population. Hodgkinson (1987) studied extended families in Iceland and didn’t find any evidence of the different genes in relation to bipolar disorder. Wender et al...