(A01) Biological Treatments To OCD

• Drug therapy SSRIs

  Drug therapy for mental disorders increase/decrease levels of transmitters in the brain to increase/decrease their activity. To tackle the symptoms of OCD, particular type of anti-depressant drug used called a selective serotonin reuptake inhibitor
• SSRIs and serotonin


  SSRIs work on the serotonin system in the brain. Serotonin is released by the presynaptic neurons and travel across a synapse
• Travelling of serotonin

  The neurotransmitters chemically convey the signal from the presynaptic neuron to the post synaptic and that is reabsorbed by the presynaptic neuron where it is broken down/re-used
• SSRIs effect on serotonin levels in the synapse

  They prevent re-absorption and breakdown of serotonin, effectively increasing its levels in the synapse
• Effect of increased serotonin levels in the synapse due to SSRIs

  It continues to stimulate the postsynaptic neuron, compensating for whatever is wrong with the serotonin system in OCD
• Dosage/Advice

  Dosage/advice vary differently according to which SSRI is prescribed. Takes 3-4 months of daily use for SSRIs to have an impact
• Fluoxetine


  Initially gave to patient in does of 20mg but may increase if dosage not benefitting patient
• Combining SSRIs with other treatments

  Drugs often used alongside CBT to treat OCD. Drugs reduce patient's emotional symptoms meaning patients can engage more effectively with CBT. Patients may respond best to CBT alone or may benefit with drugs like Fluoxetine
• Alternatives to SSRIs

  When SSRI is not effective after 3/4 months, the does can be increase (up to 60mg for Fluoxetine) or combined with other drugs - sometimes different anti-depressants used
• Different types of anti-depressants

  Tricyclics are older type of anti-depressants like Clomipramine and have same effect on the system as SSRIs but they do have severe side-effects than SSRIs so generally kept in reserve for patients who do not respond to SSRIs
• SNRIs

  Serotonin and noradrenaline reuptake inhibitors
• SNRIs used as treatments

  In the last 5 years, a different class of anti-depressants used to treat OCD. Second line of defence for patients who do not respond to SSRIs. SNRIs increase levels of serotonin as well as another different neurotransmitter- noradrenaline