Behaviourist explanation of depression

One explanation of depression is that given by the behaviourist perspective, which assumes that all behaviour, including depression, is learnt. Typically of the behavioural approach, it refers to the two main processes: operant conditioning (learning via punishment and reinforcement) and classical conditioning (learning via association).

Seligman's infamous "learned helplessness" study which showed how dogs can be conditioned not to try to remove themselves from a negative situation demonstrated how operant conditioning could potentially lead to depression. 

One study which illustrates the behaviourist explanation of depression in humans is Lewinson et al (1990). The study aimed to compare the amount of positive reinforcements received by depressed and non-depressed patients. The sample consisted of 30 participants; a selection of these had depression, some had other disorders, and some were not diagnosed with any disorder.

It was thus an independent measures design quasi-experiment. Both the IV (the number of positive reinforcements) and the DV (depression rating) were given via self-report, through a "pleasant events schedule" and a "depression adjective checklist" where participants had to tick the adjectives they felt applied to their mood. 

The results found that there was a significant positive correlation between mood ratings and pleasant activities, however there were individual differences. Thus, it was concluded that positive reinforcement is likely to be one of several factors involved in depression. 

Therefore, the behaviourist explanation of depression is that depression is the result of conditioning and learning, and processes such as positive reinforcement are important influencing factors in the extent to which someone feels depressed.