OCD Flashcards
What is OCD?
Obsessive compulsive disorder, characterised by obsessive thoughts and compulsive behaviours
Describe behavioural characteristics of OCD
• Repetitive compulsions - anxiety reducing behaviour e.g. hand washing, turning off and on lights, etc.
• Avoidance - avoiding situations where they may come into contact with threats
Describe emotional characteristic of OCD
• Anxiety - unpleasant inner turmoil caused by obsessive thoughts
• Guilt - may feel guilty over minor moral issues and feel a need to confess these
• Disgust - feeling of revulsion or profound disapproval aroused by things like dirt or the self
Describe cognitive characteristics of OCD
• Intrusive obsessions - persistent uncontrollable thoughts which they are aware are irrational
• Hypervigilance - Enhanced state of sensory sensitivity to threats
• Catastrophic thinking - Form of irrational beliefs where patients think disasters will occur
• Awareness of irrationality - being aware these thoughts are not rational
Define polygenic conditions
A condition where a number of genes are involved in its development
How does the genetic explanation describe how OCD is caused?
- SERT gene (regulating function of serotonin) in those with OCD is mutated
- causes an increase in reabsorption of serotonin into the presynaptic neuron, decreasing serotonin in synapse
- low levels of serotonin affects transmission of mood-relevant info
-COMT gene (regulating function of dopamine) also mutated, causes decrease in reabsorption = higher levels of dopamine - more dopamine linked to compulsions
Give a strength of the genetic explanation for OCD
+ Supported by empirical research
- Nestadt et al conducted meta analysis of twin studies + found concordance rates for OCD in MZ was 68% but in DZ 31%
- shows a strong biological basis bc MZ share 100% of DNA
- however, twin studies may be flawed due to environmental influence + cannot be purely genetic as it isn’t 100%
Give a limitation of the genetic explanation of OCD
– Ignores environmental factors
- many people with OCD have experienced trauma and may have developed OCD due to this
- suggests genetic explanation is limited and not universal as it cannot be applied to everyone
- incomplete explanations which doesn’t consider all factors
Describe the worry circuit in individuals without OCD
- Orbital/prefrontal cortex sends worry signal to the thalamus
- Caudate nucleus acts as a filter, screening out irrelevant impulses, most powerful are passed to thalamus
- Thalamus sends filtered version of danger back
Describe how the worry circuit is dysfunctional for individuals with OCD
- Individuals with OCD may have problems filtering out irrelevant impulses due to low levels of serotonin
- Serotonin deficiency also initiates faulty signals from OFC
How does the Diathesis-stress model describe how OCD is caused?
Suggests some individuals have a genetic vulnerability to OCD, which may be triggered by a stressor
Give positives for neural explanations for OCD
+ Research support for the role of serotonin —> Soomro et al found SSRIs were significantly better than placebos in reducing symptoms, suggesting serotonin plays a role in OCD + real world application
+ Research support for role of PFC —> Menzies et al 2008 revealed consistent abnormalities in areas of the PFC in fMRI scans of OCD patients
Give a weakness of neural explanations for OCD
— Ignores environmental factors; establishes no cause and effect —> we cannot be certain if abnormalities in the brain cause OCD or if environmental factors cause OCD which causes neural changes; a higher level explanation may be more suitable
Which drugs can be used to OCD and how do these work?
SSRIs (Selective serotonin reuptake inhibitors) reduce reabsorption of serotonin, increasing serotonin levels in the synapse
Give strengths of drug therapy in treating OCD
+ Effective at tackling OCD symptoms
- Soomro et al found SSRIs were significantly more effective than placebos in reducing OCD for most patients
+ Cost effective and non disruptive
- cheap compared to psychological treatments, valuable for systems like NHS
- SSRIs are non disruptive to patients lives, easier to simply take a drug than regularly attend therapy sessions
