10. The Biological Approach To Treating OCD Flashcards
What is serotonin?
A neurotransmitter implicated in many behaviours and physiological processes, including eating, sleeping and depression.
What is drug therapy?
The treatment of OCD through chemical means - such drugs usually affect neurotransmitter levels.
What does therapy for mental disorders aim to do?
It’s aims to increase or decrease levels of neurotransmitters in the brain to increase/decrease their activity.
What are SSRIs?
Selective serotonin reuptake inhibitors - antidepressants
What are antidepressants used for in people with OCD?
They are used to reduce the anxiety associated with OCD
Name two SSRIs
Prozac and Paxil
How do SSRIs work?
SSRIs work by blocking the reuptake (reabsorption) of serotonin at the pre-synaptic neuron after it has fired.
By preventing the reabsorption it has the effect of increasing levels of serotonin at the synapse, prolonging its activity and increasing stimulation to the receiving neuron.
This increase in levels of the neurotransmitter has the effect of regulating mood and anxiety. (Back to normal)
What is the typical dosage of antidepressants?
A typical daily dosage of Prozac is 20mg, but this may increased if it is not benefitting the patient.
How long does it take for the daily use of SSRIs to impact upon symptoms?
3-4 months
What type of therapy are drugs often used alongside to treat OCD?
Drugs are often used alongside cognitive behavioural therapy (CBT) to treat OCD. The drugs reduce the patient’s emotional symptoms, such as feeling anxious or depressed. This means that patients can engage more effectively with CBT.
When an SSRI is not effective after 3-4 months the dose can be increased it it can be combined with other drugs. Sometime different antidepressants are tried.
What are these antidepressants called?
Tricyclics
Name a tricyclic
Clomipramine
How do trycyclics work?
They work in exactly the same way as SSRIs but block the reabsorption noradrenaline as well as serotonin (this works on levels of both dopamine and serotonin). It blocks the reabsorption of both the chemicals into the pre synaptic neuron after it has fired. As a result, mode of both of these neurotransmitters are left in the synapse, prolonging their activity.
What are the advantages and disadvantages of tricyclics compared to SSRIs?
Tricyclics have the advantage of targeting more than one neurotransmitter. However, they have greater side effects than SSRIs so are used as a second-line treatment when SSRIs are not effective.
If a patient fails to respond to SSRI or Clomipramine some patients may also be prescribed an antipsychotic medication. Name one.
Risperidone
What effect do antipsychotic drugs have?
These drugs have dopamine lowering effect that have proven useful in reducing depressions and anxiety symptoms in people with OCD whose symptoms have not responded to an SSRI alone.
What is a placebo?
A sugar substitute of a drug that contains none of the actual drug.
EVALUATION OF DRUG THERAPY
Give two strengths of drug therapy
- a strength of drug therapy is that it is effective at tackling OCD symptoms
- a strength is that drugs are cost-effective and non-disruptive
EVALUATION OF DRUG THERAPY
Explain the strength of drug therapy in that it is effective at tackling OCD symptoms
For example, Soomro et al reviewed 17 studies comparing SSRIs to placebos in the treatment of OCD. All 17 studies showed significantly better results for SSRIs than for the placebo conditions.
Effectiveness is greatest when SSRIs are combined with a psychological treatment, usually CBT. Typically symptoms reduce for around 70% of patients taking SSRIs, the rest are helped by alternative drugs or CBT + drugs.
So drugs can help most patients with OCD which is strength.
EVALUATION OF DRUG THERAPY
Explain the strength of drug therapy in that it is cost effective and non-disruptive
A strength of drug treatments in general is that they are cheap compared to psychological treatments. Using drugs to treat OCD is therefore good value for the NHS. As compared to psychological therapies SSRIs are also non-disruptive to patients’ lives. If you wish you can simply take drugs until you symptoms decline and not engage with the hard work of psychological therapy.
Many doctors and patients like drug treatments for this reason.
EVALUATION OF DRUG THERAPY
Outline the three limitations of drug therapy
- a limitation is that drugs can have side-effects
- a limitation is the evidence for drug treatment is unreliable
- one problem is that some cases of OCD follow trauma
EVALUATION OF DRUG THERAPY
Explain the limitation of drug therapy in that it can have side-effects
Although drugs like SSRIs are often helpful, a significant minority will get no benefit. Some patients also suffer side-effects. For example some side-effects of SSRIs are indigestion,blurred vision and loss of sex drive.
For those taking Clomipramine, side-effects are more common and be more serious. More than 1 in 10 patients suffer erection problems and weight gain, 1 in 100 become aggressive and suffer disruption to blood pressure and heart rhythm.
Such factors reduce effectiveness because people stop taking the medication which is a weakness.
EVALUATION OF DRUG THERAPY
Explain the limitation of drug therapy in that the evidence for drug treatment is unreliable
Although SSRIs are fairly effective and any side-effects will probably be short term, like all drug treatments, SSRIs have some controversy attached. For example, some believe that evidence favouring drug treatments is biased because it is sponsored by drug companies who do not report all evidence.
A weakness is that such companies may try to suppress evidence that does not support the effectiveness of their drugs to maximise their economic gain.
EVALUATION OF DRUG THERAPY
Explain the limitation of drug therapy in that some cases of OCD follow trauma
OCD is widely believed to be biological in origin. It makes sense therefore that the standard treatment should be biological. However, it is acknowledged that OCD can have a range of other causes, and in that some cases it is a response to traumatic life events.
It may not be appropriate to use drugs when treating cases that follow a trauma when psychological therapies may provide the best option which is a weakness for drug treatment.
What is the dis thesis-stress model?
It is an eclectic idea that suggests you need a genetic vulnerability and a stressful trigger.
