This essay will be examining how clinical psychologists explain depression. It will also outline and evaluate two key psychological perspectives for depression which are biological and cognitive. The clinical symptoms of depression are characterised by over-whelming sadness,consisting of a extensive range of feelings,thoughts and physical manifestations. Such as suicidal thoughts,pessimism,low self esteem and feelings of despondency and helplessness. A depressed individual will also display a variety of motivational deficits, such as loss of interest in everyday activities or hobbies. It is also common for an depressed individual to display a lack of initiative and spontaneity. This lack of initiative may manifest itself into social withdrawal and also effect things like appetite and libido (Davey,2011).


One biological account for depression is genetics. The biological perspective considers that certain individuals have certain genes which predisposes an individual to depression. Meaning depression can be inherited. Studies show that the increased risk of depressive symptoms for relatives of individuals with clinical depression is around 5-10% and is higher than would be expected in the general population (Kendler,1993). Studies of twins also suggest an inherited element in mood disorders. They have consistently determined concordance rates of around 46% for monozygotic (MZ) twins compared to 20% for dizygotic (DZ) twins. These results reinforce the case for a genetic element to depression (Davey,2011). This is further reinforced from evidence from studies on adoption.

In 1986 Wender el al,carried out an adoption study which looked at whether factors like environment or genetics were more likely to be associated with depression in adopted adults. The study was conducted using a sample of 71 adults who had both been adopted and had a diagnosed mood disorder. Psychiatric evaluations were conducted of both the biological and adoptive parents to investigate where there was a greater than normal correlation between depression in adoptive adults and depression in adopted or biological parents.

The results from this study showed that adoptive parents were eight times less likely to have depression and the biological parents having depression correlated more significantly with depression in the adopted children than the adopted parents having depression. These results from this study reinforce the case for mood disorders such as depression having a genetic link and further reinforces why one biological account for depression is genetics.

Another biological account for depression is neurochemical. Depression and other mood disorders have also been shown to be connected with abnormalities in levels of certain brain neurotransmitters and two of the most significant neurotransmitters are serotonin and norepinephrine. Serotonin is involved in the transmission of nerve impulses, whilst norepinephrine is the chemical released from the sympathetic nervous system in response to stress.

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Depression is frequently correlated with low levels of both of these neurotransmitters. A variety of factors contributed to these findings about the significance of serotonin and norepinephrine levels. In the 1950’s it was discovered that many of the medications used to treat individual’s with high blood pressure also caused depression (Ayd,1956). This development was found to be the result of this type of medication decreasing brain serotonin levels.

This period also saw the development of drugs that significantly reduced the symptoms of depression,these were tricyclic drugs (e.g. imipramine) and monamine oxidase (MAO) inhibitors (e.g. trancylcpromine). These drugs work by increasing levels of both serotonin and norepinephrine in the brain. With the findings leading to the development of neurochemical theories of depression that argue that depression is caused by either low norepinephrine activities (Bunney & Davis,1965) or low serotonin activity (Golden & Gilmore,1990). Because these neurotransmitters are fundamental for the successful transmission of impulses between neurones, this reinforces the idea that their abnormally low levels in individuals with depression may account for the cognitive,behavioural and motivational deficits found in depression and other mood disorders (Davey,2011).

The Cognitive account for depression suggests that depression results from maladaptive, irrational or faulty cognitions which take the form of distorted thoughts and judgements. It also suggests that depressive cognitions can be socially or observationally learnt. For example,when children in a dysfunctional family observe their parents fail to successfully cope with stressful experiences or traumatic events. The cognitive account for depression also suggests that depressive cognitions are the result of the lack of experiences that would aid the development of adaptive coping skills.

One key assumption of the cognitive theory is that depressed individuals think differently than non- depressed individuals and this difference in thinking contributes to them becoming depressed. For example, depressed individuals are likely to view themselves,their environment and their future in a pessimistic way. This results in a depressed individual having the tendency to misinterpret facts in a negative ways and also results in them often blaming themselves for any adversity that occurs.

This negative thinking works to function as a negative bias,meaning it makes it effortless for depressed individuals to see circumstances as being more severe than they really are. This escalates the risk that such individuals will develop depressive symptoms as a response to stressful situations (Davey,2011). This idea is reinforced in Beck’s Cognitive Theory (1987) which claimed that depressed individuals have developed a negative schema that leads to them viewing the world and themselves in a negative way.

These negative schemas influence the selection,encoding,categorisation and evaluation of stimuli and events in the world that leads to symptomatology. Beck also argued that these negative schemas are a relatively constant characteristic of the depressed individual’s personality and develops as a result of early adverse childhood experiences. In later life, when the individual encounters a stressful experience this will reactivate this negative schema and allow the biased thinking that produces depressive symptoms such as deficits in cognitive,affective,motivational and behavioural functioning (Davey,2011).


In conclusion, biological and cognitive research are both crucial in providing clinical psychologists an explanation for depression. Biological research helps them understand abnormalities in the brain,including changes in the neurotransmitter levels,which may contribute to the development of depression in an individual. However, cognitive research also helps clinical psychologists to gain a deeper understanding of depression and its treatment.