OCD

• What is the definition of OCD?


  A condition whereby a person has obsessive thoughts and compulsive behaviours causing them anxiety.
• What is the cycle of OCD?

  ->Obsessive thought -> Anxiety -> Compulsive behaviour -> Temporary relief ->
• What are some examples of compulsive behaviours?

  -Washing / Cleaning

  -Checking and rechecking items

  -Arrangement of objects

  -Hoarding

  -Biting nails (dermatophobia)

  -Pulling out your own hair (trichotillomania)

  -Avoidance
• What are some examples of the emotional aspects of OCD?

  -Anxiety

  -Depression

  -Guilt and disgust
• What are some cognitive characteristics of OCD?

  -Obsessive thoughts

  -Hypervigilant -> excessive anxiety
• What does the Orbitofrontal cortex do and what is its role in OCD?

  -It is responsible for logical thinking and making decisions.

  -A person with OCD may have abnormal functioning / excessive activity in this, which may result in illogical decisions to keep checking and hoarding.
• What study supports the use of the Orbitofrontal cortex with OCD?

  -Ursu and Carter (2009)

  -Monitored 15 OCD px using fMRI and found hyperactivity in the OC

  ->Suggested that the OC is involved with regulating awareness of the consequences of a future behaviour

  --->If this is impaired, repetitive behaviours will occur.
• How does the parahippocampus gyrus account for the symptoms of OCD?

  -It is the circle next to the hippocampus

  -It is the process of unpleasant emotions

  ->A person with OCD may have this impaired, which subjects them to continuous processing of the emotions.
• How does the basal ganglia account for symptoms of OCD?

  -They are structures involved in the co-ordination of movement.

  ->Hyperactivity leading to disturbed communication in the BG is linked to repetitive motor functions.
• What study supports the role of the basal ganglia in response to OCD symptoms?

  -Wise and Rapoport (1989)

  -->Suggested that OCD is often found in px with Huntington's, Parkinson's and Tourette's.

  ---->This shows the association with repetitive movements.
• What are the four 'lobes' of the brain?

  -Frontal lobe

  -Paretial lobe

  -Temporal lobe

  -Occipital lobe
• What is the frontal lobe involved with?

  -Decision making

  -Speech

  -Thought

  -Learning
• What is the parietal lobe involved with?

  -Processes sensory information

  ->Touch

  ->Temperature

  ->Pain
• What is the occipital lobe involved with?

  -Processes visual information
• What is the temporal lobe involved with?

  -Hearing

  -Memory

  -Speech

  -Comprehension and production
• Synaptic transmission

  1. Axon terminals of a neuron release neurotransmitters

  2. Axon terminals form the presynaptic neuron of the synapse

  3. Impulses cross the synapse between the axon terminal and the adjacent neuron

  4. Electron impulses pass down the axon to the terminal buttons (the presynaptic terminal)

  5. Electron impulses trigger the release of chemical neurotransmitters from the vesicles on the presynaptic neurons

  6. Neurotransmitters travel across the synapse and combine with the receptors on the postsynaptic neuron
• How is serotonin involved with OCD?

  -It is the main neurotransmitter associated with OCD, leading to some cases to be explained with the reduction of this.

  -->If a person has a low level of serotonin, the normal transmission of mood regulation and other mental processes doesn't take place.

  ALSO:

  -->Serotonin has a role in the mental process which stops the repetition of tasks, so a lack of this loses the mechanism that stops task repetition.
• How is low level of serotonin treated in relation to OCD?

  -Px can use SRIs medication.

  -Stand for: Serotonin reputake inhibitors.

  -->These are anti-depression and increase serotonin levels across the synapse.

  -->They DONT introduce more serotonin.
• What evidence supports the use of serotonin in relation to OCD?

  -PET scans (Positive Emission Tomography) shows levels of the neurotransmitter to be lower in OCD suffers.

  -SRIs are effective in reducing OCD systems, which suggests that serotonin systems are involved.

  -->Insel (1992) found that SRIs can reduce symptoms of OCD in 50-60% of cases.

  --->Further supported by Zohar et al (1987) found that SSRIs alleviated symptoms by 60%

  -Found and inc levels of 5-HIAA (by-product of this) in the cerebral spinal fluid of px with OCD showing the inc brain serotonin activity.
• What is the genetic explanations of OCD?

  -People with OCD have found to have candidate genes which create vulnerability to developing the disorder, some of these genes are involved with regulating the serotonin system.

  -->Suggests that OCD is polygenic, so has several genes involved.

  -->Includes serotonin and dopamine.
• What is the evidence which supports the genetic explanation of OCD?

  -Taylor (2013)

  ->Did a meta-analysis and found up to 230 different candidate genes that may be involved in OCD

  -->An example is 5HT1-D beta, which might be inherited and has a role in the efficiency of transport of serotonin across the synapse.
• What is the evidence which supports the genetic explanation of OCD? (Family Studies)

  Family Studies:

  -Nestadt et al (2000)

  -->Found 1st degree relatives of OCD sufferes had an 11.7% chance of developing OCD, compared to 2.7% in 1st degree relatives of control px without OCD.

  -Cromer et al (2007)

  -->Found over 1/2 of px in their sample had a traumatic event in their past and their OCD was more severe in those with more than one trauma.
• What is the evidence which supports the genetic explanation of OCD? (Twin Studies)

  -Nestadt et al (2010)

  -->Found that 68% of monozygotic twins (100% identical) shared OCD as opposed to 31% of dizygotic twins.

  --->This strongly suggests a genetic influence of OCD.

  !Since the environment of DZ twins are much more similar than ordinary siblings, it suggests a shared environment is important in OCD.
• What is some biological treatment of OCD?

  -Drug therapy

  -Cognitive behavioural therapy
• How does drug therapy help as a biological treatment for OCD?

  -SSRIs prevent the reuptake of serotonin and prolong its activity in the synapse in ordered to reduce anxiety and normalise the 'worry circuit'

  --> Most common is fluoxetine

  --->Often used alongside CBT to engage more effectively.
• What are some side effects of drug therapy for OCD?

  -Headaches

  -Fatigue

  -Insomnia

  -Weight gain

  -Nausea

  -Blurred vision