The biological approach to treating OCD

What type of therapy does this approach to treating OCD focus on?

Drug therapy.

What types of drugs treat OCD?

SSRIs

Tricyclics

Benzodiazepines

D-Cycloserine

What types of drugs are SSRIs?

Antidepressants.

What does SSRI stand for?

Selective seretonin re-uptake inhibitors.

How do SSRIs treat OCD?

They increase levels of seretonin.

How does the process of seretonin re-uptake normally work?

Seretonin is released into a synapse from one neuron.

It targets receptor cells on the receiving neuron at receptor sites.

Afterwards, the seretonin is re-absorbed by the initial neuron.

Describe the seretonin re-uptake of someone who has OCD.

Reputake is too quick, so the receiving neuron doesn’t have the neurotransmitter for long enough.

This causes imbalance, so bad mood.

How do SSRIs increase levels of seretonin?

They inhibit the re-absorption of seretonin into the initial neuron.

What brands manufacture SSRIs?

Zolof

Paxil

Prozac

What types of drugs are tricyclics?

Antidepressants.

How do tricyclics treat OCD?

Tricyclics block the transporter mechanism that re-absorbs both seretonin and neurotransmitter noradrenaline into the pre-synaptic cell 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 is a brand name for tricyclics?

Anafranil

What is noradrenaline?

A neurotransmitter found mainly in areas of the brain that are involved in governing autonomic nervous system activity (eg blood pressure/ heart rate)

What advantage do tricyclics have?

They are able to target more than one neurotransmitter.

What is their disadvantage?

They have greater side effects.

Because of this, they are used as a second-line treatment for patients where SSRIs aren’t effective.

What types of drugs are benzodiazepines?

Anti-anxiety drugs.

What other names are BZs manufactured under?

Xanax

Diazepam

Explain how they treat OCD.

BZs slow down the activity of the central nervous system.

They do this by enhancing the activity of neurotransmitter GABA.

When released, this has a quietening effect on neurons on the brain, reducing anxiety.

How do BZs enhance GABA activity?

They react 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. This slows down its activity, making the person feel more relaxed.

Diagram of this

What is D-Cycloserine?

An antibiotic used in the treatment of tuberculosis.

Positive eval

Evidence for effectiveness of drug treatments - Soomro (2008) reviewed 17 studies of SSRIs as treatment for OCD patients and found them to be more effective than placebos in reducing OCD symptoms in patients up to three months after treatment.

Convenience - drug therapies require little effort and time for the patient, unlike CBT. Drug therapies are also cheaper for the government health service (psychology and the economy) than psychological treatments.

Negative eval

Side effects - SSRIs can cause nausea, headaches and insomnia. Tricyclics can cause hallucinations and irregular heartbeats, so are only used when SSRIs aren’t effective. BZs can cause serious side effects such as loss of memory and aggressiveness.

There are also problems with addiction, making it worse than the original problem of OCD.

It has been found that drug treatments aren’t a lasting cure - Maina (2001) found that patients relapse into OCD within a few weeks if medication is stopped.

Publication bias - Turner (2008) claimed that there is evidence of this where antidepressant drug companies exaggerate positive outcomes of antidepressant treatment and publish more positive results than negative. Such selective publication can lead doctors to make inappropriate treatment decisions that may not be in the best interest of their patients.