P - The biological approach to treating OCD Flashcards
What approach do we look at for treating OCD?
The biological approach.
What treatments are there for OCD?
Deep brain stimulation and drug therapy.
What are SSRIs?
A type of drug therapy used to treat OCD and depression.
What do SSRIs do to treat OCD?
Used to increase the levels of serotonin to normalise the worry circuit.
What does SSRI stand for?
Selective serotonin re-uptake inhibitors.
What is the order of drug preference in treating OCD with drug therapy from most prefered to least?
SSRIs
Tricyclics
Benzodiazepines
What are some examples of SSRIs?
Fluoxetine (e.g. prozac)
Sertraline (e.g. zoloft)
Citalopram (e.g. celexa)
How do SSRIs work?
Serotonin is released into a synapse from one nerve (neuron). It targets receptor cells on the receiving neuron at receptor sites and, afterwards, is re-absorbed by the initial neuron sending the message. In order to increase levels of serotonin at the synapse, and increase stimulation to the receiving neuron, this re-absorption (re-uptake is inhibited.
What types of drug therapies can be used to treat OCD?
SSRIs
Tricyclics
Benzodiazepines
What are tricyclics?
A type of drug therapy used to treat OCD and sometimes depression.
How do tricyclics work to treat OCD?
They block the transporter mechanism that re-absorbs both serotonin and noradrenaline into the pre-synaptic cells after it has fired. As a result, more of these neurotransmitters are left in the synapse, prolonging their activity, and easing transmission of the next impulse.
What are examples of tricyclics?
Amitriptyline (e.g. elavil)
Clomipramine (e.g. anafranil)
What are the advantages of using tricyclics compared to SSRIs?
They target more than one neurotransmitter.
What are the disadvantages of using tricyclics compared to SSRIs?
They have greater side effects.
When are tricyclics used instead of SSRIs?
When SSRIs do not work - they are a second-line treatment.
What are BZs?
Benzodiazepines - anti-anxiety drugs.
What are some examples of benzodiazepines?
Alprazolam (e.g. xanax)
Diazepam (e.g. valium)
Lorazepam (e.g. ativan)
How do benzodiazepines work to treat OCD?
They slow down the activity of the CNS by enhancing the activity of the neurotransmitter GABA, which when released has a general quietening effect on many of the neurons in the brain.
It does this by reacting with special sites (called GABA receptors) on the outside of receiving neurons. When GABA locks into these receptors it opens a channel that increases the flow of chloride ions into the neuron. Chloride ions make it harder for the neuron to be stimulated by other neurotransmitters, thus slowing down its activity and making the person feel more relaxed.
Apart from SSRIs, tricyclics and BZs, what other drugs can be used to treat OCD?
D-Cycloserine.
What does D-Cycloserine do and what can it be used to treat?
Reduces anxiety and thus may be an effective treatment for OCD, particularly when it is used in conjunction with psychotherapy.
What is D-Cycloserine?
An antibiotic used in the treatment of tuberculosis but it also appears to enhance the transmission of GABA and thus reduce anxiety (Kushner et al., 2007).
What does GABA stand for?
Gamma-aminobutyric acid.
What is GABA?
A neurotransmitter that regulates excitement in the nervous system, thus acting as a natural form of anxiety reducer.
What is noradrenaline?
A neurotransmitter found mainly in areas of the brain that are involved in governing autonomic nervous system activity, e.g. blood pressure or heart rate.
What is serotonin?
A neurotransmitter implicated in many different behaviours and physiological processes, including aggression, eating behaviour, sleep and depression.
