OCD

• Biological Approach to treating OCD:

  • Obsessive: Cognitive element:
  • Persistent or forbidden thoughts that cause anxiety
  • Compulsive: Behavioural element:
  • Repetitive behaviour to reduce anxiety caused by obsessions
  • Disorder: Depression element:
  • Co-morbid condition. High levels of anxiety which can lead to depression
• Cognitive characteristics:

  • Obsessive thoughts:
  • Recurring negative or unpleasant thoughts
  • For example, the worry that you’ve left the door unlocked
  • Awareness of irrational anxiety:
  • Sufferers are aware that their obsessions and compulsions are not rational.
  • This is required for a diagnosis of OCD
• Behavioural Characteristics:

  • Compulsions: Are repetitive
  • Sufferers feel compelled to repeat a behaviour
  • For example, hand washing.
  • Compulsions reduce anxiety
  • For most patients, compulsions are performed to manage anxiety produced by obsessions
  • About 10% of sufferers do not have obsessions, they simply have an overwhelming and irrational sense of anxiety and show compulsive behaviour alone.
  • Avoidance: A second behavioural characteristic of OCD.
  • Sufferers avoid situations that they feel may trigger their OCD.
  • Someone who washes their hands compulsively, may avoid doing jobs that mean they meet germs.
  • These can often interfere with everyday life.
• Emotional Characteristics:

  • Anxiety and Distress:
  • Obsessions and compulsions cause powerful, overwhelming anxiety which makes OCD a very distressing condition to have.
  • Obsessive thoughts can be frightening
  • The urge to repeat a behaviour causes distress. •
  • Accompanying depression: OCD is often comorbid with depression.
  • This means that it may be accompanied by a low mood and a lack of enjoyment.
  • Completing compulsions can bring some relief from the depression but it is only temporary.
  • Guilt and disgust:
  • Anxiety and depression can be accompanied by other unpleasant emotions such as guilt over minor moral issues and disgust (can be due to germs).
• Genetic Explanations for OCD: AO1

  • Individuals receive specific genes from their parents which influence the onset of OCD.
  • Lewis (1936):
  • Of his sample, 37% had parents with OCD.
  • 21% had siblings who had OCD.
  • This suggests that what is passed from one generation to the next, is a biological vulnerability.
  • OCD is a polygenic condition.
  • Taylor (2013):
  • COMT GENE: Regulates the function of dopamine.
  • The variation in the COMT gene, causes a decrease in the COMT activity and a higher level of dopamine in the brain.
  • This causes a higher level of dopamine and is more common in patients with OCD than without.
  • SERT GENE: Associated with the transport of Serotonin.
  • The mutation to this gene causes an increase in transporter proteins at a neuron’s membrane which leads to an increase in the re-uptake of Serotonin causing a lower level of serotonin in the synapse.
• Genetic Explanations: AO3 Evidence:

  • Nestadt et al (2000):
  • 80 patients with OCD and 343 of their near relatives compared with a control group without mental illness and their respective relatives.
  • Strong link with near family = greater risk if had first degree relative.
  • Billett et al (1998):
  • Meta-analysis of twin studies.
  • On average identical twins are 2x more likely to develop the disorder than fraternal twins.
  • Ozaki et al (2003):
  • Mutation of the SERT gene was found in two unrelated families where 6 of the 7 family members had OCD.
• Genetic and Neural Explanations: AO3: Strength:

  • There is good supporting evidence for the suggestion that a vulnerability for OCD is inherited genetically.
  • Researchers can estimate the proportion of variance in a trait attributable to genetic variation versus the proportion that is due to shared or unshared environment which is highly useful to treat OCD.
  • For example, Nestadt et al (2010) found that 68% of MZ twins shared OCD, as opposed to 31% of DZ twins.
  • Billett et al (1998), who found that MZ twins are twice as likely to develop OCD than DZ twins through performing a meta-analysis of 14 twin studies.
• Genetic and Neural Explanations: AO3: Weakness:

  • It is not truly representative of the reasons behind the development of OCD and therefore can be argued to be somewhat of a reductionist view.
  • OCD manifests in genetically vulnerable individuals following an activating event that triggers the disorder.
  • Cromer et al (2007) support the diathesis-stress model as it found that over half of the OCD patients in the same sample experienced a traumatic event in their past - and that it was more severe in patients who experienced multiple traumas.