Affective Disorder: Depression

Discuss to what extent biological, cognitive and sociocultural factors influence abnormal behaviour

Evaluate psychological research (that is, theories and/or studies) relevant to the study of abnormal 

To what extent do biological, cognitive and sociocultural factors influence abnormal behaviour

This essay will focus on the biological, cognitive and social factors that influence the affect disorder: depression. People who are depressed usually experience feelings of guilt and sadness, lack of enjoyment or pleasure in anything. They will have frequently negative thoughts about themselves, including low self-esteem and suicidal thoughts.

The biological factors that I will be focusing on is evolutionary origins, genetic predisposition and effects of neurotransmitters.

Hagen et al suggested that depression has evolutionary origins. It is a psychological adaption favoured by natural selection and serves two purposes: to signal need and elicit help from others. He suggested that depression is evolved towards loss and failure. The feelings of sadness triggered by loss or failure is adaptive because it would discourage the behaviour that led to it, thus preventing even greater loss. This may explain why females are more susceptible to depression because of the defeat in competition with males. However, evolutionary theories of depression remain speculative and there has not been much evidence to prove that this is true.

Genetic researchers argue that genetic predisposition may predispose some people to develop depression more easily than others. Nurnberger and Gershon reviewed the results of 7 twin studies with monozygotic and dizygotic twins in which one pair had been diagnosed with depression. He found that the concordance rate (which is the inheritance of two related individuals) to be higher for monozygotic twins (65%) compared to dizygotic twins (14%). This supports the hypothesis that genetic factors might predispose some people to depression. Long-term stress may result in depression in some individuals who have this genetic predisposition which makes them more vulnerable and susceptible in developing depression compared to those that do not have this genetic predisposition. However, because the concordance rate was not 100%, this means that genetics are not entirely to blame, but that other factors may have influenced depression as well. 

Another biological explanation is neurotransmitters. Janowsky et al suggested that depression may stem from an imbalance in neurotransmitters. He gave participants a drug that decreased noradrenaline in their body, and found that participants became profoundly depressed within minutes of having taken the drug. The fact that depression can be artificially induced by certain drugs suggest that some cases of depression might stem from a disturbance in neurotransmission. In a similar study, Teutung et al analysed and compared urine samples from depressed and non-depressed patients. He found that depressed people's urine had lower levels of noradrenaline and serotonin compared to non-depressed patients, and concluded that depressed people have lower levels of certain neurotransmitters. However, abnormal levels of neurotransmitters may not cause depression, but may be the case that depression causes imbalances in neurotransmission - the direction of cause and effect is uncertain. The human body is very complex, and so we cannot simply attribute our behaviour to neurotransmitters.

After identifying the biological factors that could influence depression, we are still left without a clear understanding of how depression may develop. The evolutionary theory seems vague without much supported evidence, genetic predisposition is not 100%, and the direction of cause in neurotransmitter is uncertain. 

Perhaps the cognitive level of analysis may suggest a more clear understanding, as it is more related to how we develop depression in the first place. Beck et al suggested that cognitive distortion theory of depression, which are ways in which our mind convinces us of something that isn't true. He proposed that a person's cognitive vulnerability to depression is based on negative schemas, which are activated by stressful events. This gives the person a pessimistic attitude about themselves, the world and the future, making it very difficult for the person to see anything positive in life.

Wessman and Beck assessed the thought processes of depressed people to establish if they were using negative schemas. Thought processes were assessed by using the dysfunctional attitude scale (DAS). Participants were asked to fill in a questionnaire by ticking whether they agreed or disagreed with a set of statements. They found that depressed people were more likely to make negative assessments than non-depressed people. This supports Beck's theory that depression is based on negative schemas. However, because the study was based on questionnaires, there is the question of whether it is valid because people may not take questionnaires seriously or their answers may just be guesses. 

In another study, Alloy et al followed a sample of young Americans in their 20s for 6 years. Their thinking style was tested and they were placed in the "positive thinking group" and the "negative thinking group" according to their ways of thinking. After 6 years, they found that only 1% of those in the positive thinking group developed depression compared to 17% of those in the negative thinking group. The results indicate that there may be a link between negative cognitions and depression. This, again, supports Beck's theory. 

However, Beck's theory is reductionist, meaning it doesn't take into consideration biological or sociocultural factors and how they interact. The participants in the study may have been influenced by other factors, such as genes or social/cultural factors, and not purely by the way they think. Also, not everyone in the negative thinking group developed depression, meaning that not everyone who has this pattern of thinking became depressed. 

To derive oneself to think negatively about themselves and their lives may mean that they must've been influenced in some way by social or cultural factors. No doubt bad lifestyle and intense stress will contribute to our mood.

Brown and Harris wanted to investigate the social factors that might contribute to depression in women of child-bearing age. They interviewed a total of 400 women and found that a total of 15% of women were depressed and 18% were on the borderline of being depressed. They identified the following contributory social factors that lead to depression:

- not having paid unemployment

- having 3 or more children under the age of 14 living at home

- not having a close and confiding relationship with a partner

- loss of their own mother in childhood

Brown and Harris also found that working-class women were five times more likely to be depressed than middle-class women, perhaps because of the stress that they experience in relation. Social factors, such as isolation, stress, poverty and lack of support with child care, all contribute to the onset of depression, according to Brown and Harris.

Culture may also influence our onset of depression, as some cultures discourage depression more than others. For example, Chiao et al found that depression was higher in individualistic cultures than in collectivistic cultures. Similarly, Gabilondo et al found that depression occurs less frequently in Spain (collectivistic culture) and there there is a lower suicidal rate compared to Europe countries (individualistic). This is perhaps because collectivist groups discourage depression as they have more social support than individualistic cultures, who encourage independence. 

The sociocultural approach seems much more clear as we tend to be depressed when we are under stress or when we are lonely and without friends. 

It may also be the interaction of biological, cognitive and sociocultural factors that causes depression. For example, depression may be the result of a genetic predisposition, with precipitating events in the environment (i.e. stress) combined with negative cognitive distortions.