3.1 Behaviourist theory and operant conditioning

Behaviourist theory focuses on observable behaviour and places emphasis on the importance of the environment in shaping behaviour. Operant conditioning (Lewinsohn, 1974) considers the cause of depression to be the removal of positive reinforcement from the environment, or situations that would serve to reinforce ‘maladaptive’ behaviour, leading to increased social isolation, and an inability to seek or respond to alternative sources of positive reinforcement. However, while these theories offer an explanation where the cause of depression is known (or observed), they are more problematic where the underlying cause is undefined (‘endogenous’ depression), and fail to take into account the influence of thought (cognition) on mood.