biological approach treating ocd

• SSRIs

  selective serotonin re-uptake inhibitors
• what do antidepressants do ?

  increase serotonin levels because low levels of serotonin associated with depression and ocd
• Antidepressants reduce

  Anxiety associated with ocd
• how do SSRIs work ?

  serotonin released into synapse from neuron , targets receptor cells on receiving neuron at receptor sites , re-absorbed by initial neuron

  to increase serotonin at synapse and increase stimulation to receiving neuron , this re-absorption(re-uptake) is inhibited
• coys and schneier 2008

  SSRIs currently preferred treatments of anxiety disorder
• tricyclics

  1st antidepressant used for ocd
• what do tricyclics do ?

  block transporter mechanism that re-absorbs serotonin and noradrenaline into the pre-synaptic cell after it has been fired
• result of tricyclics

  more of these neurotransmitters left in synapse , prolonging activity and easing transmission of next impulse
• advantage of tricyclics

  target more than one neurotransmitters
• disadvantage of tricyclics

  more side effects so used as 2nd line treatment when SSRIs not effective
• D-Cycloseline

  reduces anxiety, may be effective ocd treatment especially when used with psychotherapy
• what is D-Cycloseline?

  antibiotic to treat tuberculosis but also enhances neurotransmitters of GABA so reduces anxiety - Kushner et al 2007
• Benzodiazepines (BZs)

  reduce anxiety
• how do BZs reduce anxiety?

  slow down activity of CNS by enhancing activity of neurotransmitter GABA
• GABA

  gamm-aminobutyric acid
• what does GABA do?

  quietening effect on many neurons in brain
• how does gaba do this?

  reacts with GABA receptors on outside of receiving neurons , opens channel that increases flow of chloride ions into the neuron , chloride ions make it harder for neuron to be stimulated by other neurotransmitters, thus slowing down activity and making person feel relaxed
• evidence for effectiveness of drugs

  randomised control trial used to compare effectiveness of drug vs placebo

  soomro et al 2007 reviewed 17 studies of use of SSRIs with ocd patients and found more effective than placebos in reducing symptoms of ocd up to 3 months after treatment
• drug therapies preferred

  need little effort/ time

  cbt-regular meetings and thought to tackle problems

  drug therapies-cheaper for health service as costs less than psychological treatments

  drugs more economical for health service than psychological therapies
• drugs have side effects

  soomro et al 2008 - nausea,headache,insomnia are common side effects of SSRIs , often enough to make patient stop taking drug

  side effects and possibility of addiction limit usefulness of drugs as treatments for ocd
• tricyclic antidepressants

  More side effects (hallucinations and irregular heartbeat)than SSRIs so only used when SSRIs not effective
• drugs not a lasting cure

  Maina et al 2001 found that patients relapse within few weeks if medication stopped

  Koran et al 2007 reviewed ocd treatments and suggested that drugs more commonly used but psychotherapies should be tried first
• publication bias

  Turner et al 2008 claims there is evidence of a publication bias to show positive outcome of antidepressants , exaggerating their benefits

  drug companies fund research and have interest in success of psychotherapeutic drugs

  Selective publication leads to doctors making inappropriate treatment decisions