The Biological Approach to treating OCD

• Tricyclics:

  1. The tricyclic Anafranil was the first antidepressant to be used for OCD
  2. They block the transporter mechanism that re-absorbs both serotonin and noradrenaline
  3. As a result, more of these neurotransmitters are left in the synapse to be taken in by receptors
• Noradrenaline?

  A neurotransmitter involved in fight or flight - makes you feel calmer
• Anti depressants - SSRIs:

  1. Commonly used
  2. Low levels of serotonin are associated with depression and OCD
  3. These drugs lower the levels of serotonin - by blocking the reuptake
  4. Normalises the worry circuit
• What does SSRI stand for?

  Selective Serotonin Re-uptake Inhibitors

  1. Prozac
  2. Zoloft
  3. Paxil
• Anti anxiety drugs:

  1. Benzodiazepines (BZs) are commonly used to reduce anxiety
  2. Trade names Librium, Xanax, Valium and Diazepam
  3. Slow down the central nervous system by enhancing the activity of the NT GABA
• What does GABA stand for?

  Gamma-aminobutyric acid - has a general quieting effect on many of the neurons in the brain - slowing down the activity - slows down the central nervous system
• What does GABA do?

  Increases the flow of chlorine ions into the neuron

  Chlorine ions make it harder for the neuron to be stimulated by other NTs - slowing down its activity

  highly addictive in higher doses
• Tricyclic = anti depressant e.g. Anafranil?


  Blocks the transporter mechanism that re-absorbs both serotonin and noradrenaline - more of these neurotransmitters are left in the synapse to be taken in by receptors
• SSRIs = anti depressants e.g. Prozac, Zoloft, Paxil?


  Increase the levels of serotonin which normalises the worry circuit
• Benzodiazepines = anti anxiety e.g. Librium, Xanax, Valium, Diazepam?


  Slow down the central nervous system by enhancing the activity of the NT GABA - has a general quieting effect of many of the neurons in the brain, slows the activity, increase the flow of chlorine ions in the neuron which makes it harder for the neuron to be stimulated by other NTs
• Effectiveness - does the drug work?

  Soomro et al reviewed 17 studies of the use of SSRIs with OCD patients and found them to be more effective than placebos - shows that SSRIs do improve the symptoms of OCD.

  However - may be issues with the meta analysis - may have been different conditions within the studies
• Little long term evidence of effectiveness exists - Koran et al - demonstrates that drugs treat symptoms not causes - only a short term treatment
• Preference - why is it preferred over other drugs? Price/ease?

  Little effort required in taking drugs - much less effort than CBT (5-20 weeks - fortnightly sessions)

  cheaper

  Require very little monitoring (4-6 weeks)

  1. in terms of the economy
  2. in terms of doctors time - 6 people in 1 hour vs 1 person an hour
• Preference - Koran er al in their review of treatments recommended that Psychological treatments such as CBT should be tried first - because drugs are not a lasting cure, relapse is common (Manna et al) - drugs stop working/ side effects so bad they'd rather have OCD

  Sufferers also benefit from talking to the GP about symptoms and treatment
• Side effects - what are the side effects of the drug?

  1. Side effects of BZ's can be aggression and long term impairment of the memory. Problems with addictions. Should therefore only be used for a limited time - 4 weeks at a time
  2. Side effects of SSRIs are headaches, nausea and insomnia
  3. Side effects of Tricyclics are hallucinations and irregular heartbeat
  4. side effects = stop taking drug
• Bias in results - are some studies flawed?

  Turner et al - publication is bias towards studies that show as positive outcome - publication bias - much research is funded by drug companies - selective publication can lead doctors to make inappropriate treatment decisions
• For drugs?

  1. cheap
  2. quick
  3. symptom relief
• Against drugs?

  1. side effects
  2. publication bias