Role of genetic factors is supported by family studies
Type: Strength
Study: Nestadt et al. (2000)
- Found people with family members with OCD had a 5x greater risk of having OCD themselves at some point compared to the general population
- However families typically share the same environments and genes
- Meaning that environmental factors could also play a part in the development of OCD
Research support from brain scanning research
Type: Strength
Study: Menzies et al. (2007)
- People with OCD and their very close relatives have reduced grey matter in key brain regions, including the orbitofrontal frontal cortex
- Supports the view that neural differences are inherited and may lead to OCD in certain people
- Studies suggest that brain scans could be used in the future as a way of detecting people’s risk of developing OCD
Real-world applications
Type: Strength
- Research into the biological explanation of OCD has led to the hope that specific genes could be linked to particular mental and physical disorders
- For example, where a parent-to-be has the COMT gene, the mother’s fertilised egg can be screened
- Gene therapy may produce a means of turning certain genes ‘off’ so that a disorder such as OCD isn’t expressed
- Helping to prevent mental disorders such as OCD
Alternative explanations
Type: Limitation
- Ignores important psychological factors
- For example, the two-process model suggests that OCD may be caused by association between a neutral stimulus and anxiety (classical conditioning
- It also suggests that this association is maintained through operant conditioning because the stimulus causing anxiety is avoided through compulsive behaviours
- Therefore it is important to consider psychological causes of OCD as well as biological causes