AO1
Drug therapy for mental disorders aims to increase or decrease levels of neurotransmitters in the brain or to increase/decrease their activity. We know that low levels of serotonin are associated with OCD. Therefore drugs work in various ways to increase the level of serotonin in the brain.
SSRIs / Combining SSRIs with other treatments
Selective Serotonin Reuptake Inhibitors (SSRIs) is a type of antidepressant that is used to tackle the symptoms of OCD. SSRIs work on the serotonin system in the brain. Serotonin is released by certain neurons and travels across a synapse. The neurotransmitter chemically conveys the signal from the presynaptic neuron to the postsynaptic neuron and then it is reabsorbed by the presynaptic neuron where it is broken down and re-used (see picture).
By preventing the absorption and breakdown of serotonin SSRIs effectively increase its levels in the synapse and thus continue to stimulate the postsynaptic neuron. This compensates for whatever is wrong with the serotonin system in OCD.
Dosage and other advice vary according to which SSRI is prescribed. A typical daily dose of Fluoxetine is 20mg although this may be increased if it is not benefitting the patient. The drug is available as capsules or liquid. It takes three to four months of daily use for SSRIs to have much impact on your system. / Drugs are often used alongside cognitive behaviour therapy (CBT) to treat OCD. The drugs reduce a patient’s emotional symptoms, such as feeling anxious or depressed. This means that patients can engage more effectively with the CBT.
In practice some people respond best to CBT alone whilst others benefit more from drugs like Fluoxetine. Occasionally other drugs are prescribed alongside SSRIs.
Alternatives to SSRIs
Where an SSRI is not effective after three to four months the dose can be increased (e.g. up to 60mg a day for Fluoxetine) or it can be combined with other drugs. Sometimes different antidepressants are tried. Patients respond very differently to different drugs and alternatives work well for some people and not at all for others.
- Trycyclics (and older type of antidepressant) are sometimes used, such as Clomipramine. These have the same effect on the serotonin system as SSRIs. Clomipramine has more sever side-effects than SSRIs so it is generally kept in reserve for patients who do not respond to SSRIs.
- SNRIs (serotonin-noradrenaline reuptake inhibitors). In the last five years a different class of antidepressant drugs called SNRIs has also been used to treat OCD. These are, like Clomipramine, as econd line of defence for patients who don’t respond to SSRIs. SNRIs increase levels of serotonin as well as another different neurotransmitter (noradrenaline).
AO3: Evaluation of the Biological Treatments of OCD
Effectiveness
P: One strength of the use of drug therapy to treat OCD is that there is supportive evidence to show they are effective.
E: For example, Soomro et al. (2009) reviewed studies comparing SSRIs to placebos in the treatment of OCD and concluded that all 17 studies showed significantly better results for the SSRIs than for the placebo conditions.
E: This is a strength because we can see that the drugs have a significant impact on the symptoms of OCD. Typically 70% of patients who use SRRIs see a decline in symptoms. However, for the other 30%, alternative drug therapies, or a combination of drug therapy and psychological treatments would be more effective.
L: As a result, the credibility for drug therapy as a biological treatment of OCD is increased. / Cost-effective and non-disruptive
P: One strength of the use of drug therapy as a treatment for OCD is that they are cost-effective and non-disruptive.
E: For example, using drug therapy is a much cheaper alternative to suing psychological therapies, and is a much easier solution for the patient.
E: This is a strength because using drugs as a treatment for OCD is better value for a public health system like the NHS. SSRIs (compared to psychological therapies) are also non-disruptive to patient’s lives; you can simply take drugs until your symptoms decline and not engage with the hard work in psychological therapies such as CBT and REBT.
L: This means drug therapies as a biological treatment for OCD can be seen as a more appropriate method of treatment for some patients. / Potential side-effects
P: One issue with using drugs as a treatment for OCD is that patients may suffer quite severe side-effects.
E: For example, for those taking Clomipramine, side-effects are more common and often more serious. More than one in ten patients suffer erection problems, tremors and weight gain. More than one in a hundred become aggressive and suffer disruption to blood pressure and heart rhythm according to research by the NHS.
E: This is an issue because although the drugs are helpful, and the side-effects are more severe for Clomipramine than other antidepressants, those patients taking SSRIs could still either not benefit at all from the drug, or still experience some side-effects including: indigestion, blurred vision and loss of libido (sex drive).
L: Because of the risk factor associated with drug therapy, it casts doubt over the benefit and overall effectiveness of drug therapy as a biological treatment for OCD.