Specification:  The biological approach to treating OCD: drug therapy.

Biological treatments of OCD and other illnesses use drug therapy (sometimes called pharmacotherapy) to correct the abnormal levels of serotonin. Biological explanations of OCD have a lot of support and so it is likely that biological treatments will be effective.

Anti-anxiety drugs

Benzodiazepines (BZs) are a range of anti‐anxiety drugs that include trade names like Valium and Diazepam. BZs work by enhancing the action of the neurotransmitter GABA (gamma‐aminobutyric acid). GABA tells neurons in the brain to ‘slow down’ and ‘stop firing’ and around 40% of the neurons in the brain respond to GABA. This means that BZs have a general quietening influence on the brain and consequently reduce anxiety, which is experienced as a result of the obsessive thoughts common in OCD.

Some neurons have GABA receptor sites at the synapse and when GABA locks into one of these, the flow of chloride ions into the neuron is increased. The chloride ions make it more difficult for the receiving neuron to be stimulated by further neurotransmitters. Thus the nervous system is slowed down making the patient feel more relaxed. 

Evaluation

One strength of biological treatments for OCD comes from research support for their effectiveness. Randomised drug trials compare the effectiveness of SSRIs and a drug with no pharmacological value, called a placebo. Soomro et al. (2008) conducted a review of research examining the effectiveness of SSRIs and found that they were significantly more effective than placebos in the treatment of OCD, across 17 different trials. This supports the use of biological treatments, especially SSRIs, for OCD. However, studies such as this are criticised for only concluding the short‐term effectiveness of drug treatments with long‐term effects still to be investigated empirically.

An advantage to biological treatments for OCD is their cost effectiveness. Drug therapies, such as SSRIs and BZs, are relatively cost‐effective in comparison with psychological treatments, like cognitive behavioural therapy (CBT). Consequently, many doctors prefer the use of drugs to psychological treatments, as they are a more cost‐effective solution for treating OCD, which is beneficial for health service providers. In addition, psychological treatments like CBT require a patient to be motivated to engage whereas drugs are non‐disruptive to everyday life, and can simply be taken until the symptoms subside. As a result, this means that drug treatments are likely to be more successful for patients who lack the motivation to complete intense psychological treatments.

A limitation of prescribing drug treatments for OCD is the possible side effects of drugs like SSRIs and BZs. Although evidence suggests that SSRIs are effective in treating OCD, some patients experience mild side effects like indigestion, while other might experience more serious side effects like hallucinations, erection problems and raised blood pressure. BZs are renowned for being highly addictive and can also cause increased aggression and long‐term memory impairments. As a result, BZs are recommended for short‐term treatment only of up to four weeks, according to Ashton (1997). Consequently, side effects diminish the effectiveness of drug treatments, as patients will often stop taking medication if they experience negative side effects.

Drug treatments are criticised for treating the symptoms of the disorder and not the cause. Although SSRIs work by increasing the levels of serotonin in the brain, which reduces anxiety and alleviates the symptoms of OCD, it does not treat the underlying cause of OCD. Furthermore, once a patient stops taking the drug, they are prone to relapse. Koran et al. (2007) suggest that psychological treatments such as CBT may be a more effective long‐term solution to provide a lasting treatment and a potential cure.