OCD

• Basic definition of OCD?

  It is described as an anxiety disorder with 1.3% in the UK. There are 2 main types of symptoms for OCD:

  1. Obsessions: These are persistent thought or impulses which cause anxiety 
  2. Compulsions: These are repetitive behaviours or mental acts in response to the obsession, which usually reduce anxiety

  • These two are related.
  • Cleaning your hands too much may be due to fear of bacterial contamination.
  • The compulsion may not always follow logically from the obsession where to avoid disastrous things happening they turn the lights on and off many times. 
• Emotional characteristics of OCD?

  Obsessions and compulsions are a source of anxiety, sufferers know that compulsions are excessive and it causes feelings of shame.
• Behavioural characteristics of OCD?

  • Compulsions ARE the behavioural acts.
  • They reduce anxiety created by obsessions, they are repetitive acts like hand washing, checking.
  • People feel like they need to carry out these acts to prevent dreadful things from happening.
  • Sometimes they do not follow logically from the acts like turning a light on and off multiple times. 
• Cognitive characteristics of OCD?

  • Obsessions ARE the cognitive characteristic.
  • They are persistent intrusive thoughts which can be frightening or embarrassing.
  • They are mental thoughts or impulses which feel excessive and uncontrollable.
  • The person recognises that they are a product of their own mind and not unreasonable
• What is the biological approach to OCD? (genetics)

  • People with genetic dispositions for mental illnesses can pass down their “abnormal” genes
  • We can assume that relatives may also have that same gene for sharing psychological abnormalities.
• Biological approach to OCD? (Neural)

  • Development of mental illnesses can be described in the low or high concentration of neurotransmitters, which are chemical messengers within nerve cells.
  • Neuroanatomy explanation: Physical damage to the brain during birth or an accident may happen due to levels of neurotransmitter levels
• What does family studies show about genetics?

  • Biological relatives share genes, the closer their biological relationships the greater the number of genes they share!
  • 1st degree relatives such as parent or child or siblings share 50% of genes but grandparents and grandchildren share 25% of genes.
  • With this logic, all of them should have a disorder.
  • They are also raised in similar environments which makes it harder to differentiate separating the effect of genes and environment.
• What do twin studies show about genetics?

  • Useful for understanding the difference between environment and genes.
  • MZ twins and DZ twins are compared. MZ twins have 100% sharing of genes compared to DZ twins of 50%.
  • Both sets of twins have the same environment. If MZ twins are more similar than DZ twins, this is due to genes, if both sets are similar, this is due to the environment.
  • Researchers look at the number of twins who have the disorder and it is known as the concordance rate.
• Genetic explanation to OCD?

  • Individuals inherit specific genes related to OCD.
  • The COMT gene may be related to it as it controls production of neurotransmitter dopamine.
  • This gene variation causes lower activity of the COMT gene and causes higher levels of dopamine. (more of it in OCD people)
  • The SERT gene affects the transport of serotonin, which lessens the number for it.
  • Taylor (2013) found evidence that there may be more than 230 genes involved in OCD, showing that it may be polygenic. This means that OCD is not caused by a single gene but that there are several genes.
• Evidence for genetic explanation in twin studies for OCD?

  • Twin studies have also been used to investigate the role of OCD. Monozygotic twins both share 100% of their genes so if one develops OCD then theoretically, the other twin should too as well.
  • Nestadt et al (2010) found that MZ twins had a 68% chance of developing it if the other had it but only 31% for DZ twins. 
• Evidence for genetic explanation in family studies?

  • Family studies show that relatives of OCD sufferers have more likelihood to suffer from OCD
  • Nestadt et al (2000) compared OCD sufferers with first degree relatives and did the same but for non OCD sufferers.  Relatives of OCD had 5x likelihood to develop OCD than the control group. 
• What is a short evaluation for genetic evidence?

  • MZ may have more similar environments than DZ twins due to how they are treated.
  • Twins look identical so the MZ twins may be why they are similar rather than the genes.
  • This undermines the theory behind the MZ and DZ comparisons.
• What is the neural explanation for OCD?

  • Low serotonin and high dopamine control OCD.
  • Frontal lobe is responsible for decision making and logical thinking: 
  • Orbitofrontal cortex is in decision making and worrying.
  • A malfunctioning OFC results in anxiety and planning to avoid anxiety (obsessions).
  • Thalamus is responsible for cleaning, checking and other safety behaviours. An overactive thalamus results in increased motivations for cleaning or checking for safety (compulsions)
  • Serotonin malfunctions Orbitofrontal cortex and high levels of dopamine affect over activity in nervous system.
• Supporting studies for neural mechanisms in OCD?

  • Supporting studies come from PET scans of patients with OCD taken while their symptoms are active.
  • This can happen when people with a germ obsession hold a dirty cloth, they show an increase in the OFC activity indicating a region of OCD
• Supporting studies to do with drugs for OCD?

  • Supporting studies can be shown from findings of drug treatments found to decrease OCD activity.
  • This has implications for providing effective treatments.
  • These work by altering neurotransmitter levels if there is an imbalance such as using drugs to raise serotonin levels (70% effectiveness for OCD)
• Negative evaluation regarding OCD for reductionism?

  • It reduces causes of abnormality to biological causes such as genetics.
  • Too simplistic as there are other causes of OCD such as the environment, our thought processes and the unconscious
  • Cromer (2007) found over half of OCD patients in their sample suffer from a traumatic event in their past
  • The behaviourist two step process can also be applied
  • Initial learning occurs at classical conditioning when a stimulus is associated with anxiety
  • Maintained through operant conditioning as the stimulus is avoided using compulsive behaviours 
• Negative evaluation regarding blame for OCD?

  • The cause is not biological so it takes the blame away from the mental illness away from the patient it isn’t their fault they are suffering.
  • The cognitive approach however makes patients feel like they are to blame for OCD as it is their faulty thinking causing the disorder.
  • Accepting a genetic cause of OCD may make patients feel like they passed on the genes
• Negative evaluation regarding determinism?

  • The theory argues that the cause of OCD is biologically deterministic, it removes responsibility and control from the individual, making them powerless.
  • If you have the COMT/SERT gene, the neuroanatomy you have as well, will make you have OCD.
  • This theory is deterministic and removes freewill from the patient. 
• What is the assumption of biological treatments?

  • Drug treatments work on the assumption that an imbalance of neurotransmitters is what causes the OCD.
  • Antidepressant drugs are the most common type to treat OCD.
  • Low levels of serotonin are associated with OCD + depression so by raising it, we can stop OCD.
• What do SSRI's do?

  • These are the standard antidepressant drugs for OCD, some examples include fluoxetine, prozac and zoloft. 
  • During neurotransmission, serotonin is released by the presynaptic neuron and diffuses across the synapse to the postsynaptic neuron.
  • Serotonin is reabsorbed by the uptake pump, broken down and reused.
  • However the SSRIs prevent the reabsorption by blocking the reuptake pump increasing serotonin levels. 
• How are the SSRI's prescribed?

  • Dosage will vary according to the SSRI; a typical dose of fluoxetine is 20mg but can increase if not helpful.
  • It takes 3-4 months to be helpful and it is available in capsules or liquid. 
  • If the drug is not helping after 3-4 months, dosage or different antidepressants can be used like Tricyclics.
  • They have the same effect but they have much more severe impacts and is only used for non patients who do not respond to SSRIs
• Supporting study for SSRI drugs?

  • Supporting study for the effectiveness of the SSRI drug.
  • Soomro et al found that in 17 studies comparing the effects of SSRI and placebo in OCD that there were better results for SSRI’S.
  • Symptoms decline for around 70% of patients taking SSRI’s. Therefore, drugs help most patients with OCD
• Positive evaluation regarding familiarity of drugs?

  • It allows many people to live normally and improve quality of life.
  • Many people prefer using drugs rather than therapy.
  • Therapy is less familiar than medicine, which is more disruptive.
  • However, drugs remove control from the patient and place it into the hands of the doctor whereas therapy would give them more control.
  • It gives familiarity but less control essentially. 
• Negative evaluation regarding terrible side effects?

  • Some patients suffer side effects. Common side effects of SSRI’s include nausea, headaches and insomnia.
  • However, tricyclics are worse.
  • 1 in 10 will suffer from erection problems, tremors, weight gain.
  • 1 in 100 will suffer aggression and arrhythmia.
  • This means that these drugs are not appropriate for all.
• Negative evaluation of drug therapy?

  • A further weakness of this drug therapy is that there are issues with studies showing the positive effectiveness of drugs.
  • These are due to publication bias where negative or neutral findings are not published.
  • It has been found that research funded by the drug companies are likely to find more favourable results than research by other sources.
  • It may be likely that drug companies suppress damaging findings