OCD

what are the DSM-5 categorisations for OCD?

• obsessions (recurring thoughts, images, etc)

• compulsions (repetitive behaviours - e.g. hand washing, counting, etc)

what are some behavioural characteristics of OCD

• compulsions are repetitive

• compulsions reduce anxiety

  • behaviours are done in an attempt to reduce the anxiety produced by an obsession

    • for example, if you don’t move the chair so it’s facing the right way, something bad will happen

• avoidance

  • reduce anxiety by keeping away from the situation

what are some emotional characteristics of OCD

• anxiety and distress

• accompanying depression

  • low mood and a lack of enjoyment

• guilt and disgust

what are some cognitive characteristics of OCD

• obsessive thoughts

  • 90% experience this

  • unpleasant and recurring

• cognitive coping strategies

  • praying, mediation, etc

  • can make them appear more normal

• insight into excessive anxiety

  • the person is aware that their obsessions and compulsions aren’t rational but they still think about the worst-case scenarios that might happen

  • this can cause hypervigilance (extreme alertness)

what is the biological approach to explaining OCD

• genes

  • evidence from twin and family studies suggest the role of genes

• neural

  • genes associated with OCD are likely to impact structures of the brain and levels of key neurotransmitters

explain some of the evidence of the involvement of genes in OCD

• lewis (1936) found 37% of patients had parents with OCD, 21% had siblings with OCD

  • genetic vulnerability

  • exposure to stress in the environment is needed

    • this is the basis of the diathesis stress explanation

    • it suggests that some people have a biological predisposition to develop OCD, but this only happens when there is the right variables in the environment to do so

• the SERT gene (5-HTT) has been implicate in OCD due to its role in transporting serotonin across the synapse

  • leads to low levels of serotonin

• COMT gene regulates dopamine production, and may also be implicated in OCD

  • low activity of gene = high dopamine = OCD

  • suggested by Tukel et al 2013

• OCD is likely to be a polygenetic

  • taylor (2013) suggested that up to 230 genes may be involved in OCD

explain some of the evidence for neural involvement in OCD

• MRI reveals that grey matter in the brain provides support for the worry circuit explanation

  • grey matter = essential tissues in the brain and spinal chord that plays an important part in memory, emotions, and movement

  • in areas of the brain like orbitofrontal cortex, involved in emotion, reward-related, decision making

    • all shows that abnormal anatomical differences can be inherited

• lateral frontal lobes involved in decision making and logical thought may not be functioning properly

• the left parahippocampal gyrus, associated with processing unpleasant emotions, may function abnormally in OCD

• low serotonin prevents normal transmission of mood-relevant information

  • impacts other mental processes

• high dopamine = irrational thoughts

• low serotonin and high dopamine may be the cause of obsessive focused thoughts during periods of low mood

evaluate some of the strengths of the genetic explanation of OCD

• nestadt et al (2010) found 68% of all MZ twins had OCD, while 31% of DZ twins had it