The cognitive approach predominantly focuses on thoughts as a means of understanding human behaviour. The key assumption being our actions are the result of our thoughts. The approach has been successfully applied to therapies, most notably 'CBT' (cognitive-behavioural therapy). CBT uses the assumptions of the cognitive approach, by assuming that maladaptive behaviour (such as depression) is the result of maladaptive thoughts (such as negative thinking). Whilst this is a bit too simplistic as an explanation for a complex mental illness such as depression, having this explanation helps people to change their thoughts as a means of changing their behaviour. This is an example of how the cognitive approach is uselful because it can be used to help people in real life. However, this example also highlights the main issue of the cognitive approach - that it is reductionist. This means that the approach cannot fully explain complex behaviour, as there are many biological and environmental factors that the cognitive approach does not account for. Furthermore, thoughts are pretty hard to study scientifically, which makes testing the claims of the approach difficult!