Biological Approach to Treating OCD

• Antidepressants: SSRIs


  standard drug treatment for OCD involves Serotonin Selective Reuptake Inhibitors (SSRIs).

  usually, serotonin is released by the presynaptic neurone and travels across the synapse to receptors on receiving neurone.

  then reabsorbed by the presynaptic neurone and reused.

  SSRIs block the presynaptic reuptake sites so serotonin can't be reabsorbed, effectively increasing levels of serotonin in the synapse allowing it to continue to stimulate the postsynaptic receptors.

  typical SSRI: fluoxetine given at a daily dose of 20mg, although this can be increased.
• Other Drug Treatments

  if a patient is unresponsive to SSRIs, a second option is an antidepressant called tricyclic.

  e.g. clomipramine was historically the first antidepressant to be given to OCD sufferers.

  tricyclics block the reuptake of both serotonin and noradrenaline -> have greater side effects and therefore aren't offered as the 1st treatment option
• Anti-anxiety drugs

  also given to treat the anxiety which accompanies OCD. patients are given benzodiazepines (BZs) which increase the effectiveness of a naturally occurring neurochemical called GABA (gamma aminobutyric acid)

  produce this chemical when we need to calm our physiological responses and brain activity.

  BZs mimic GABA and lead to less nerve activity in the brain therefore reducing anxiety
• Weakness - SSRIs have potentially unpleasant side effects

  some patients also suffer side effects such as indigestion, blurred vision and loss of sex drive.

  these side effects are usually temporary

  for those taking clomipramine, side effect are more common and can be more serious.

  more than 1 in 10 patients suffer erection problems, tremors + weight gain.

  more than 1 in 100 become aggressive + suffer disruption to blood pressure
• Strength - considerable evidence to suggest they're effective

  Soomro et al reviewed studies comparing SSRIs to placebos. in the treatment of OCD + concluded that all 17 studies reviewed showed significantly better results for the SSRIs than for placebo conditions.

  effectiveness is greatest when SSRIs are combined with a psychological treatment.

  typically symptoms decline significantly for around 70% of patients taking SSRIs
• Strength - requires little effort on behalf of the patient

  good value for a public health system like the NHS. as compared to psychological therapies, SSRIs are non-disruptive to a patient's life.

  if you wish you can simply take drugs until your symptoms decline and not engage with the hard work of psychological therapy
• Weakness - drug therapy is limited and not long-term

  drugs only offer temporary alleviation of symptoms. when the patient stops taking them the effectiveness ceases.

  may be preferable in the long term to seek psychological treatment - and deal with the actual problem
• Weakness - studies showing effectiveness of antidepressant may exaggerate their effectiveness

  although SSRIs are fairly effective and any side-effects will probably be short-term

  some psychologists believe the evidence favouring drug treatments is biased because the research is sponsored by drug companies who don't report all the evidence (Goldacre)