Explanations of obsessive-compulsive disorder — common mistakes

For top marks in evaluation questions, compare the explanations directly. For example, you can argue that biological explanations are reductionist as they simplify OCD to genes or chemicals, whereas the cognitive-behavioural explanation is more holistic by considering the interplay of thoughts and behaviours. However, the biological approach is more scientifically testable. Using an interactionist approach, like the diathesis-stress model, can be a sophisticated way to conclude that both biological and psychological factors are important.

No, this is a common misconception. Genetic explanations point to a predisposition or vulnerability, not a certainty. OCD is polygenic (involving many genes) and environmental factors (stressors) play a crucial role in triggering the disorder, as explained by the diathesis-stress model. Concordance rates in identical twins are never 100%.

Not necessarily. This is a classic 'correlation vs. causation' issue. While the effectiveness of SSRIs (which increase serotonin levels) provides strong support for the biochemical explanation, it doesn't prove that low serotonin is the initial cause. It could be that OCD itself causes a change in serotonin levels, or that another, unknown factor is involved. This is known as the treatment-aetiology fallacy.

No, this oversimplifies the cognitive explanation. Everyone has occasional intrusive or 'bad' thoughts. The core of the cognitive model of OCD is not the thought itself, but the catastrophic misinterpretation of that thought. A person with OCD might believe the thought is deeply significant, reveals something terrible about them, and that they are solely responsible for preventing a feared outcome, which leads to extreme anxiety and compulsions.