OCD treatments and evaluations

drug therapies and synaptic transmission recap

• Attempts to increase or decrease levels of neurotransmitters or the activity of neurotransmitters in the brain

• Alters the biological makeup of a person to treat the symptoms of a mental illness

• Research has shown that drug therapy can work faster than both cognitive and behavioural treatments

• One issue with drug therapy is side effects - Prozac has been associated with an increase in suicidal thoughts

 

• Drugs used to treat OCD work in various ways to increase the level of serotonin in the brain since low levels of serotonin have been associated with OCD

• Synaptic transmission is the process by which one neuron communicates with another

• Involves the release of chemical messengers called neurotransmitters from the presynaptic neuron, which bind to receptors on the postsynaptic

Process

• Vesicles release neurotransmitters into the synaptic cleft through exocytosis

• Neurotransmitters move across the synapse through diffusion and bind to receptors and activate them

• Excess neurotransmitters are re-taken up by presynaptic synapse

• Vesicles are replenished with new and reused neurotransmitters

drug treatments for OCD

• Selective serotonin reuptake inhibitors

  • Serotonin is released by certain neurons in the brain

  • Released from presynaptic neuron and travels across the synaptic cleft

  • Serotonin binds to receptor sites on postsynaptic neuron, chemically transmitting the signal from the presynaptic neuron

  • Serotonin which is not absorbed into the post-synaptic neuron is re-absorbed by the presynaptic neuron to be reused

  • SSRIs increase the level of serotonin available in the synapse by preventing it form being reabsorbed in the presynaptic neuron

  • More serotonin being received by postsynaptic neuron

• More info about SSRIs

  • Antidepressant drugs increase serotonin levels at synapses to help with reducing the anxiety associated with obsessions in OCD

  • SSRIs block the re-uptake of serotonin at the pre-synaptic membrane, increasing serotonin concentration at the synapse and continuing to stimulate the post-synaptic neuron

• Examples of SSRIs

  • Fluoxetine, citalopram, sertraline

  • Typical dose is 20mg and can be increased up to 60mg if they have no effect

  • It can take up to 3-4 months of daily use for these to have much impact on symptoms

  • Liquid or capsules

 

• Tricyclic antidepressants

  • First antidepressants used for OCD

  • TA's such as clomipramine have more side effects than SSRIs and so are used as a second-line treatment for when SSRIs are not effective

  • A typical dose is 25mg and can be increased up to 150mg if they have no effect

  • It takes a couple of weeks for these to have an impact on symptoms

 

• Serotonin-noradrenaline reuptake inhibitors

  • Have been more recently used in attempts to treat OCD, particularly for people who don't respond well to SSRIs

  • SNRIs increase levels of serotonin as well as noradrenaline (another neurotransmitters)

  • More common SNRIs are duloxetine, venlafaxine, desvenlafaxine

CBT

• Drugs are typically used in combination with CBT to treat OCD

• Reduction in a person's emotional symptoms as shown by drugs means that people can engage effectively with the CBT

• Some people respond best to CBT alone or also with drugs

strengths of OCD treatments

• Good evidence for its effectiveness - reduce symptom severity and improve quality of life

• Julien (2007) reported that studies of SSRIs show that although the symptoms do not fully disappear, between 50% and 80% of OCD patients improve, allowing them to live a fairly normal lifestyle, which they wouldn’t be able to do without the treatment.

• Furthermore, Soomro et al (2009) reviewed studies comparing SSRIs to placebos in the treatment of OCD and concluded that all 17 studies reviewed showed significantly better results for SSRIs than for placebo conditions. These studies suggest that altering serotonin levels in OCD patients often helps to reduce the symptoms and that despite drug treatments not always being completely effective, they should still be considered as a possible treatment option for people who suffer from OCD. 70% reduction in people taking SSRIs and remaining 30% can be helped with drugs and therapies

• However, Skapinakis et al. (2016) conducted a review and found that cognitive and exposure therapies were more effective than SSRIs for those with OCD. So drugs may not be optimum treatment

 

• Cost-effective and non-disruptive to people's lives

• Many thousands of tablets or liquids can be manufactured whilst one therapy session happens so cheaper

• Good value for public health systems and represents good use of limited funds

• Take the symptoms until they go, no need to attend sessions so time-effective too

weaknesses of OCD treatments

• Drug treatments reduce obsessive thoughts and compulsive behaviour to such a level that a normal lifestyle can be achieved however they do not ‘cure’ OCD. They may be an appropriate and effective short-term treatment, however, if medication is stopped, patients suffer relapse of their symptoms. Therefore, drug treatments could be seen as less appropriate, in contrast to psychological treatments, as they do not allow the sufferer to actually overcome their obsessive thoughts and compulsive behaviours.

• It may also be seen as a more cost-effective option compared to other therapeutic options such as talking therapy.

 

• Patients can experience a number of side effects with drug treatments. These are typically short-term but can be distressing and for some minorities they may be long-lasting

• For example, loss of appetite, loss of sex drive, irritability, sleep pattern disturbance and headaches are all common side effects. This could mean that it may not always be an appropriate treatment for all OCD sufferers plus if the side effects are severe enough, it could actually lead to the patient stopping the treatment all together.

• 1 in 10 experience erection problems or weight gain, 1 in 100 become more aggressive or experience heart problems.

• Reduced quality of life so drugs are no longer effective

 

• Controversy over evidence of the effectiveness of drugs 

• Many psychologists worry that researchers are funded by big drug companies to ‘prove’ that their drugs are effective and safe, and they may selectively publish positive outcomes to increase their profit. (publication bias) - Goldacre 2013

  • HOWEVER lack of independent studies of drug effectiveness and research on psychological therapies may be biased, best evidence available is supportive of drugs usefulness