OCD

• What are the 2 biological explanations for ocd

  Neural

  genetic
• What is the genetic explanation of ocd

  Genes inherited from parents and so is argued ocd is genetically inherited

  Lewis - found 37% had parents with ocd and 21% had siblings with ocd

  nestadt et al - mz twins concordance rate was 68% and dz was 31%

  OCD seems to be polygenic (more than 1 gene involved)

  taylor - found 230 different genes may be involved in OCD

  SERT gene - low seretonin levels

  COMT gene- high levels of dopamine
• What is a strength of the genetic explanation of ocd

  Strong evidence - nestadt et al - found twin concordance rates. in early study he found that people who had first degree relative of ocd 5 times more likely to be at risk of developing ocd
• what are 2 weaknesses of the genetic explanation of ocd

  Concordance rates never 100% which implies other factors like evnironment must be involved. Genes can make you more vulnerable to get ocd but other factors like trauma is needed to fully develop disorder

  Cromer et al- over half ocd patients had trauma (those with more trauma had more severe ocd)

  
  

  too many candidate genes- not successful identifying all genes involves (little predictive value)
• What is the neural explanation of ocd

  low levels of serotonin - imbalanced neurotransmitter levels. Therefore brain doesn't receive correct chemical messages

  Pigott et al - patients that took antidepressants (raises serotonin levels) reported less ocd symptoms (fewer obsessions and compulsion).

  people with ocd can have abnormal brain circuits which may be caused by low serotonin levels. In the frontal lobes of the brain is the caudate nucleus which suppresses worry signals, however in ocd patients it is damaged causing the brain to be overstimulated by worries which then causes a worry circuit this means the brain is constantly activated. Brain scans support this
• What is a strength of neural explanations for ocd

  supporting evidence - success of drug treatments - reduce symptoms by increasing serotonin.
• what are 2 weaknesses of the neural explanation for ocd?

  Cant assume cause or consequence as unsure whether brain malfunctioning and low serotonin levels is a consequence or a cause

  Due to co-morbidity (two mental disorders) symptoms of depression and ocd overlap weakening role of serotonin to explain ocd
• What are the drug treatments for ocd

  SSRIs (selective serotonin reuptake inhibitor) BZs (benzodiazepines)

  SSRIs- rebalance and increase serotonin levels. serotonin released into synapse from pre-synaptic nerve and after targeting receptor cell is reabsorbed by initial nerve. SSRIs reduce reabsorbtion process.

  BZs increase the levels of GABA which reduces anxiety and has a calming effect
• what are the 2 strengths of drug therapy as a treatment for ocd

  cheap compared to psychological treatments and non disruptive as they dont require much commitment and motivation to take them

  effective - research suggests around 70% respond well to SSRIs, Soomro et al reviewed 17 ocd studies and found drugs more effective than placebo in reducing symptoms after 3 months
• what are the 2 weaknesses of drug therapies for ocd treatment

  possible side effects- SSRIs side effects are headaches, insomnia and nausea, possible side effects of BZs are agression and LTM impairment this raises ethical issues (is it ethical to replace ocd symptoms for other medical conditions.)

  only short term cure as it dont address psychological factors that could be the root of the problem. Maina et al found many patients relapsed after drug use was stopped