Drug therapies 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 works in various ways ro increase the level of serotonin in the brain.
Selective serotonin reuptake inhibitors (SSRIs)
They prevent the reabsorption and breakdown of serotonin in the brain. This increases its level 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
Fluoxetine (an SSRI) is 20mg although this may be increased if its not benefiting the person.
It takes 3-4 months of daily use for SSRIs to impact upon symptoms.
Dose can be increased (e.g 60mg a day) if this is appropriate.
Combining SSRIs with CBT
Drugs are often used alongside CBT to treat OCD.
The drugs reduce a person’s emotional symptoms, such as feeling anxious or depressed. This means that they can engage more effectively with CBT.
Alternatives to SSRIs
Tricyclics (an older type of antidepressant) = they have the same effect on the serotonin system as SSRIs but the side effects can be more severe.
SNRIs (serotonin noradrenaline reuptake inhibitor - antidepressant) = like tricyclics there are second line of defence for people who don’t respond to SSRIs. SNRIs increase levels of serotonin as well as noradrenaline.
