One strength of this cognitive explanation for depression is its application to therapy. The cognitive ideas have been used to develop effective treatments for depression, including Cognitive Behavioural Therapy (CBT) and Rational Emotive Behaviour Therapy (REBT), which was developed from Ellis’s ABC model. These therapies attempt to identify and challenge negative, irrational thoughts and have been successfully used to treat people with depression, providing further support to the cognitive explanation of depression.
However, one weakness of the cognitive approach is that it does not explain the origins of irrational thoughts and most of the research in this area is correlational. Therefore, we are unable to determine if negative, irrational thoughts cause depression, or whether a person’s depression leads to a negative mindset. Therefore, it is possible that other factors, for example genes and neurotransmitters, are the cause of depression and one of the side effects of depression are negative, irrational thoughts.
Extension: Furthermore, there are alternative explanations which suggest that depression is a biological condition, caused by genes and neurotransmitters. Research has focused on the role of the neurotransmitter serotonin and found lower levels in patients with depression. In addition, drug therapies, including SSRIs (selective serotonin reuptake inhibiters), which increase the level of serotonin, are found to be effective in the treatment of depression, which provide further support for the role of neurotransmitters, in the development of depression.
Finally, there is research evidence which supports the cognitive explanation of depression. Boury et al. (2001) found that patients with depression were more likely to misinterpret information negatively (cognitive bias) and feel hopeless about their future (negative triad), which supports different components of Beck’s theory and the idea that cognitions are involved in depression.