Biological Approach to Treating OCD (AQA AS Psychology)

Drug therapy for OCD

• The biological approach to treating OCD assumes that the disorder is the result of low levels of serotonin in the brain

• Serotonin is a neurotransmitter associated with mood

  • Low or irregular levels of serotonin may lead to an imbalance in mood e.g. feeling down, feeling manic, feeling anxious

  • An imbalance in mood may interfere with rational thinking and could lead to obsessive thoughts - a key characteristic of OCD

Antidepressant drugs

• Antidepressant drugs used to tackle low levels of serotonin are known as Selective Serotonin Reuptake Inhibitors (SSRIs)

  • Reuptake occurs when molecules of serotonin do not cross the synaptic cleft i.e. they have not been transmitted to the postsynaptic neuron

    • The ‘spare’ molecules of serotonin are then taken back up into the presynaptic neuron

  • SSRIs work by preventing (or inhibiting) the reuptake of serotonin in the synaptic cleft back into the presynaptic neuron

  • Prevention of reuptake makes serotonin more accessible in the brain

  • More serotonin is then available to improve the transmission of messages between neurons

  • SSRIs are called selective because they mainly affect serotonin, not other neurotransmitters such as dopamine

  • SSRIs are commonly used to treat depression but they have also been found to be effective in the treatment of OCD

Anti-anxiety drugs

• OCD may also be treated using benzodiazepines (BZs)

  • BZs are anti-anxiety drugs designed to induce a feeling of calm (one well-known brand is Valium)

  • BZs encourage the transmission of gamma-aminobutyric acid (GABA)

  • GABA is a a neurotransmitter which works to control neuron hyperactivity which is associated with fear, anxiety and stress

  • BZs thus help to 'quieten' the brain by reducing neurotransmission

  • This quietening effect has been linked to the reduction of obsessive thoughts in someone with OCD

Evaluation of drug therapy for OCD

Strengths

• Drug therapy is cost-effective and widely available

  • Drugs are cheaper and more readily available than other psychological treatments such as CBT

  • The impact on the economy is lessened

    • This is good in terms of health service budgets

    • If more people are treated, they may return to work quicker which positively impacts the economy

• There is good research support for the efficacy of drug therapy

  • Researchers (Greist et al., 1995) conducted a meta-analysis where they reviewed placebo-controlled trials

    • They found that drugs in each study were significantly more effective than the placebo at reducing the symptoms of OCD

Limitations

• Drug therapies can come with potentially serious side effects

  • SSRIs may cause blurred vision, loss of libido, irritability, indigestion, and sleep disturbances

  • BZs may cause drowsiness, light-headedness, confusion, dizziness and slurred speech

    • This limits the usefulness of these drugs in the treatment of OCD

• Positive results of drug trials are more likely to be published than trials in which the outcome of the drug was less successful (known as publication bias)

  • Goldacre (2013) found that drug companies selectively publish positive outcomes for the drugs their sponsors are selling

  • As well as being unethical, the above practice lessens the validity of drug therapies

    • If only positive results are published, is the drug truly effective in treating OCD?