Biological approach to treating OCD

• drug treatment for mental disorders aims to increase or decrease levels of neurotransmitters in the brain or to increase/decrease their activity.

  low levels of serotonin are associated with OCD. therefore, drugs work in various ways to increase the level of serotonin in the brain.
• what are SSRIs?

  selective serotonin reuptake inhibitors
• what do SSRIs do?

  they prevent the reabsorption and breakdown of serotonin in the brain. this increases its levels in the synapse and thus serotonin continues to stimulate the postsynaptic neuron. this compensates for whatever is wrong with the serotonin system in OCD.
• typical dosage of SSRIs

  typical daily dose of fluoxetine (an SSRI) is 20mg, although this may be increased if it isn't benefitting the patient. it makes 3-4 months of daily use for SSRIs to impact upon symptoms.
• combining SSRIs with CBT.

  drugs are often used alongside cognitive behaviour therapy to treat OCD. the drugs reduce a patient's emotional symptoms, such as feeling anxious or depressed which means that patients can engage more effectively with CBT.
• what are two alternatives to SSRIs?

  tricyclics and SNRIs.
• tricyclics

  an older type of antidepressant which are sometimes used, e.g. clomipramine. they have the same effect on the serotonin system as SSRIs but may have more severe side-effects.
• SNRIs

  in the last five years a different class of antidepressant called serotonin noradrenaline reuptake inhibitor (SNRIs) has also been used to treat OCD. they are a second line of defence for patients who don't respond to SSRIs. they increase levels of serotonin as well as nonadrenaline.
• what are SNRIs?

  serotonin noradrenaline reuptake inhibitors.
• strength of drug therapy- effective at tackling OCD symptoms.

  soomro et al. reviewed 17 studied comparing SSRIs to placebos in treatment of OCD. all studies showed significantly better results for SSRIs than for the placebo conditions. effectiveness is greatest when SSRIs are combined with a psychological treatment, usually CBT. typically symptoms reduce for around 70% of patients taking SSRIs, the rest are helped by alternative drugs or CBT+drugs. so drugs can help most patients with OCD.
• limitation of drug treatments- evidence supporting them is unreliable

  although SSRIs are fairly effective and any side-effects will probably be short-term, like all drug treatments, SSRIs have some controversy attached. e.g. some believe the evidence favouring drug treatments is biased as it is sponsored by drugs companies who do not report all evidence. such companies may try to suppress evidence that does not support the effectiveness of certain drugs to maximise their economic gain.
• limitation of drug treatments- some cases of OCD follow trauma

  OCD is widely believed to be biological in origin. it makes sense therefore that the standard treatment shield be biological. however, it is acknowledged that OCD can have a range of other causes and that in some cases it is a response to traumatic life events. it may not be appropriate to use drugs when treating cases that follow a trauma when psychological therapies may provide the best option.
• strength: drugs are cost-effective and non-disruptive

  a strength of drug treatments in general is that they are cheap compared to psychological treatments. using drugs to treat OCD is therefore good value for the NHS. as compared to psychological therapies, SSRIs are also non-disruptive to patients' lives. if you wish you can simply take drugs until your symptoms decline and not engage with the hard work of psychological therapy. many doctors and patients like drug treatments for these reasons.