Biological approach to treating OCD

• SSRI antidepressants are the most commonly used drug to reduce the anxiety associated with OCD. They block the reuptake the of serotonin in the presynaptic membrane, increasing serotonin concentration at receptor sites on the postsynaptic membrane
• Since low serotonin levels are implicated in the brains worry ‘circuit’, increasing serotonin may have the effect of normalising this circuit
• Tricyclic antidepressants block the transporter mechanism that reabsorbs both serotonin and noradrenaline into the presynaptic cells that released them. The effect of this is to increase both serotonin and noradrenaline levels
• Tricyclics have more side effects than SSRIs and so are used as a second-line treatment when SSRIs haven’t been effective
• Benzodiazepine anti-anxiety drugs are also used to treat OCD. They enhance the activity of gamma-aminobutyric acid (GABA), which has a general quieting effect on many brain neurons
• BZs react with GABA receptors on the receiving neuron. This makes it harder for the neuron to be stimulated by other neurotransmitters. The neuron's activity is slowed down, and induces feelings of relaxation