PSYCH; OCD

whats OCD

Obsessive Compulsive Disorder;

a condition characterised by obsessions/compulsive behaviour

what are the 2 behavioural characteristics of OCD

compulsions - repetitive behaviour to reduce anxiety e.g hand washing/ checking locks

avoidance - keep away from situations that trigger anxiety

what are the 3 emotional characteristics of OCD

anxiety/distress - unpleasant emotional experience

accompanying depression - low mood/lack of enjoyment

guilt/disgust - towards self or external e.g dirt

what are the 3 cognitive characteristics of OCD

obsessive thoughts - thoughts that recur over and over/uncertainty of something

cognitive coping strategies - excessive praying/meditating to help manage anxiety

insight into excessive anxiety - aware of their irrationality and experience catastrophic thoughts about worst case scenarios

whats the genetic explanation of OCD

that genes are involved in vulnerability to OCD in individuals (demonstrated by Aubrey Lewis (1936 )

suggesting that OCD runs in families

what did Aubrey Lewis (1936) find and suggest

observed that 37% of his OCD patients had parents with OCD and 21% of them had siblings with OCD

suggesting OCD run-in families — genes are transmitted from parents to offspring i.e inherited

what is the diathesis stress model

an explanation of OCD;

suggest that some environmental stress (experience) is necessary to trigger the condition e.g a stressor

as it suggests that its not certain genes can leave people likely to develop a disorder

whats a candidate gene

genes that create vulnerability for OCD

whats meant by OCD is polygenic

means that OCD is not caused by one single gene but by a combination of genetic variations that together increase vulnerability for OCD

e.g variation of COMT gene - causes higher levels of dopamine found in people with OCD

e.g variations of SERT gene - causes lower levels of serotonin which is associated w OCD

who demonstrated that OCD is polygenic

Taylor (2013) analysed findings of previous studies and found that unto 230 different genes may be involved in OCD.

e.g genes involved in action of dopamine and serotonin (both have a role in regulating mood)

give 2 examples of neurotransmitters

dopamine

serotonin

whats meant by the OCD is aetiologically heterogeneous

means that the origins (aetiology) of OCD vary from one person to another (heterogenous)

used to describe that OCD can be caused by one group of genes in one person and a different group of genes may cause it another person

list the features of the genetic explanation of OCD

gene inheritance

diathesis stress model

candidate genes

ocd îs polygenic

ocd îs aetiologically hetereogenous

what are the two genes that have variations associated with OCD

COMT - variation of this gene causes higher levels of dopamine

SERT - variation of this gene causes lower levels of serotonin

whats the neural explanation of OCD

focuses on neurotransmitters and brain structures affects that can cause OCD symptoms

effect of serotonin on OCD

low levels of serotonin are associated with mood disorders e.g OCD/depression

possibly caused by SERT gene

effect of dopamine on OCD

higher levels of dopamine are associated with OCD symptoms e.g compulsive behaviours

what are the two nuerotransmitters that are associated with OCD

serotonin

dopamine

what are the two brain regions that are involved in OCD

basal ganglia

orbitofrontal cortex

how’s the basal ganglia involved in OCD

when damaged or hyperactive (linked to high dopamine) it fails to filter out minor worries from orbito-frontal cortex (OFC)

creating a loop of intrusive thoughts

how’s the orbitofrontal cortex (OFC) involved in OCD

OFC is a region in the brain which converts sensory information into thoughts/actions — involved in decision making and impulse control

hyperactivity in OFC increases the conversion of sensory information to actions e.g compulsive behaviours and excessive anxiety

how does a damaged/hyper active basal ganglia affect OFC

fails to filter out minor worries from OFC

OFC converts all sensory information into thoughts/actions

results in compulsions/obsessions due to overriding minor worries

one strength of the genetic explanation is the strong evidence base

E; For example. Nestadt et al (2010) reviewed twin studies, found that 68% of identical twins (MZ) shared OCD compared to 31% of non identical (DZ) and another research found that a person with a family member diagnosed with OCD is 4 times as likely to develop it as someone without.

E; These research studies suggest there must be some genetic influence on the development of OCD.

L; Therefore, this increases the validity and credibility of the genetic explanation because of its strong empirical support.

one limitation of genetic explanation of OCD is that its highly deterministic, ignoring the role of the environment

E; Concordance rates are never 100% in family studies, meaning genetics cannot be the sole cause. e.g Cromer et al (2007) found that over half of OCD patients had experienced a traumatic event and OCD was more severe in those with more than one trauma

E; This suggests that environmental factors, e.g life events can trigger the onset of OCD — the diathesis stress model is a better explanation as it suggests that genetic vulnerability to OCD is triggered by an environmental stressor

L; Therefore, a purely genetic approach is reductionist as it underestimates the interactionist nature of the disorder

one limitation of the genetic explanation of OCD is that its too broad to be useful

E; For example, researchers have identified upto 230 candidate genes create vulnerability to OCD

E; This means that identifying a specific, definitive cause for a specific individual is extremely unlikely. The explanation is too broad making it difficult to use for direct diagnosis.

L;Therefore, the polygenic nature of this explanation is acknowledged, the lack of a specific gene limits the diagnostic power of the theory.

one strength of the neural explanation of OCD is the strong evidence supporting the role of neurotransmitters

E; Studies show that Selective Serotonin Reuptake Inhibitors (SSRIs) which increase serotonin levels in the synapse are effective in reducing symptoms in around 50-60% of OCD patients

E; This means if increasing serotonin successfully reduces symptoms, its logical to conclude that a low level of serotonin was a contributing cause of the OCD.

L; Therefore ,the effectiveness of SSRIs strengthens the neural explanation, specifically the role of serotonin.

one limitation of the neural explanation Is the issue of comorbidity

E; Many OCD sufferers are also diagnosed with clinical depression as depression is also associated with low serotonin levels like OCD.

E; This means that the chemical imbalance found in OCD patients might not be specific to OCD, and could be a result of the comorbid depression

L; This limits the validity of the explanation, as It fails to explain the unique symptoms of OCD vs general low mood .

one strength of the neural explanation is the use of objective, scientific methodology to identify abnormal brain structures

E; Researchers used PET scans to monitor brain activity and have shown increased activity in the OFC and the basal ganglia in OCD patients.

E; This high level of scientific technology provides objective evidence the OFC and basal ganglia are dysfunctional in those with OCD

L; This increases the scientific validity of the neural explanation as its based on empirical evidence rather than subjective reports.

whats the biological approach in treating OCD

drug therapy

what does drug therapy aim to do

increase or decrease levels of neurotransmitters and their activity in the brain

whats a SSRI

type of antidepressant drug called Selective Serotonin Reuptake Inhibitor

how do SSRIs work

work on the serotonin system in the brain

to prevent the reabsorption and breakdown of serotonin,

SSRIs block the reabsorption of serotonin at the presynaptic neurone

which increases levels of serotonin in the synapse

and continue to stimulate the post synaptic neurone

how does serotonin work in the brain

via synaptic transmission;

serotonin is released by the presynaptic neurone and travels across a synapse

and reaches the post synaptic neurone

serotonin stimulated a signal at the post synaptic neurone

then reabsorbed by the presynaptic neurone where its broken down and reused

what other treatment are SSRIs combined with to treat OCD

CBT

why is SSRIs combined with CBT to treat OCD

the drugs reduce emotional symptoms e.g anxiety

means that people with OCD can engage more effectively with CBT

what are the 2 alternatives to SSRIs

Tricyclics - older type of antidepressant e.g clomipramine that has more side effects than SSRIs

SNRIs - serotonin noradrenaline reuptake inhibitors increase serotonin levels and noradrenaline (another neurotransmitter)

one strength of drug treatment is that its highly effective at reducing OCD symptoms as shown by strong evidence;

E; For example, Soomro et al (2009) reviewed 17 studies comparing SSRIs to placebos in OCD treatment, found all 17 trials shown significantly better results for SSRIs than the placebo upto 70% patients had reduced symptoms taking SSRIs

E; This suggests that increasing serotonin levels is a valid method for managing OCD, providing strong support for the biological approach to treatment.

L; Therefore, SSRIs can be considered an effective, evidence based first line treatment for managing OCD in majority of patients

one strength of drug therapy is the cost effectiveness and convenient to patients

E; Drug therapy is non-disruptive, patient only takes a pill daily unlike CBT which requires intense, time-consuming weekly sessions and drug therapy is cheaper than psychological therapies

E; This makes them highly appropriate for patients with busy lifestyles or limited access to therapists. also benefits the NHS by allowing more patients to be treated within a budget

L; Thus, the easy use and economic benefits enhance the appropriatenss of drug therapy as a treatment option for OCD

limitation of drug therapy - negative side effects can reduce patient compliance

E; Common side effects of SSRIs include indigestion, blurred vision, loss of sex drive, weight gain, etc.

E; These side effects may cause patients to stop taking the medication, making the treatment ineffective

L; Therefore, the potential for harm and discomfort from the side effects can limit the suitability of drug therapies for certain individuals.

limitation of drug therapy - nomothetic, ignores individual differences

E; Drug therapy treats all patients the same, using the standard drug dose

E; This may not account for individual differences that may effect the result of using standard doses and treatment

L; Therefore, this limits the effectiveness and generalisability of drug therapy across all patients ie follows a nomothetic approach