Biological approach to treating OCD

• What are SSRIs?

  Selective Serotonin Reuptake Inhibitors
• How do SSRIs treat OCD?

  They increase serotonin levels by preventing reabsorption
• Why is serotonin important in treating OCD?

  Low serotonin levels are linked to OCD symptoms
• How do SSRIs help with OCD symptoms?

  They regulate mood and reduce obsessive thoughts
• How long do SSRIs typically take to show effects?

  3–4 months of daily use
• Can SSRIs be combined with psychological treatments?

  Yes, they are often combined with CBT
• What are some common side effects of SSRIs?

  Indigestion, blurred vision, loss of sex drive
• What are tricyclics?

  Older class of antidepressants like clomipramine
• How do tricyclics compare to SSRIs?

  Tricyclics can be more effective but have severe side effects
• What are SNRIs?

  Serotonin-Noradrenaline Reuptake Inhibitors
• How do SNRIs work?

  They increase levels of serotonin and noradrenaline
• Why might a doctor switch from SSRIs to clomipramine or SNRIs?

  If SSRIs are ineffective or cause intolerable side effects
• What is the advantage of combining drug therapy with CBT?

  Drug therapy reduces symptoms for better CBT engagement
• Why is drug therapy considered cost-effective for treating OCD?

  Drugs are cheap, easy to administer, and accessible
• A limitation of biological treatments for OCD, such as SSRIs, is that they can cause unpleasant side effects. For example, common side effects include indigestion, blurred vision, and a reduced sex drive, which may discourage patients from continuing their medication. These negative effects can lead to high attrition rates, meaning many patients stop treatment before it becomes effective. This lowers the overall effectiveness of the drug therapy and reduces the external validity of research findings, as real-world adherence may be lower than in clinical trials. Therefore, while SSRIs may work well in theory, their practical application is weakened by the issue of patient dropout.
• A further limitation of biological treatments for OCD is that they do not address the root cause when the disorder is triggered by trauma. Research suggests that in some cases, OCD develops as a psychological response to a past traumatic experience rather than purely from biological factors like low serotonin. SSRIs target brain chemistry but do not help individuals process the underlying emotional cause of their symptoms. This reduces the validity of SSRIs as a universal treatment, as they may only alleviate symptoms without tackling the origin of the disorder. As a result, outcomes may not be long-lasting or generalisable to all OCD sufferers, especially those with trauma-related cases.
• A strength of biological treatments for OCD is that they are supported by strong empirical evidence. Soomro et al. (2009) conducted a meta-analysis of 17 studies comparing SSRIs to placebos in the treatment of OCD and found that SSRIs were significantly more effective in reducing symptoms, especially when combined with CBT. This supports the effectiveness of SSRIs and increases the validity of the biological approach to treatment, showing that targeting serotonin can provide real symptom relief for many patients. This evidence gives clinicians confidence in prescribing SSRIs as a first-line treatment for OCD.
• A strength of biological treatments for OCD is that they are cost-effective, especially compared to psychological therapies. Drugs like SSRIs are relatively inexpensive to produce and prescribe, making them an affordable option for the NHS. Unlike psychological therapies such as CBT, which require trained professionals and multiple sessions, medication can be widely distributed and used with minimal supervision. This not only reduces healthcare costs but also allows more patients to access treatment, improving the practical application of care and enhancing quality of life on a large scale. Therefore, biological treatments are beneficial for both patients and public health services.