OCD

Cognitive Characteristics of OCD

• obsessions (persistent and intrusive thoughts)

• catastrophic thoughts (worse case if anxiety justified)

• selective attention (to source of anxiety e.g. germs)

Behavioural Characteristics of OCD

• compulsions (repetitive behaviour to reduce anxiety not always related)

• avoidance (of trigger to avoid anxiety)

Emotional Characteristics of OCD

• anxiety

• distress

• obsessive thoughts cause it

• compulsion alleviate it

What is the OCD Cycle

• obsession

• anxiety

• compulsion

• relief

What are the 2 biological explanations for OCD

• genetic

• neural

Genetic Explanation of OCD

• mental illnesses are inherited

• risk of development is higher for first-degree relatives

• 37% parents with OCD

• 21% siblings with OCD

• candidate genes (code for vulnerability to OCD)

• COMT gene - dopamine regulation

• OCD more likely high dopamine

• SERT gene - serotonin transport

• OCD more likely less serotonin

• polygenic (230 different genes involved OCD)

Twin Research Support strength of Genetic Explanation

• Nestadt et al found 68% monozygotic twins (identical) both had OCD

• 31% dizygotic twins both had OCD

• increase validity that OCD can be explained by genetics

• BUT concordance rates aren’t 100%

Research Support strength of Genetic Explanation

• Nestadt et al 80 patients with OCD 343 first degree relatives

• compared with control found OCD with first degree relative had 5 times greater risk

• BUT could be environmental factors

• families share same experience

Environmental criticism of Genetic Explanation

• environmental risk factors involved in OCD

• over half had traumatic event - more severe OCD

• interactionalist approach might be better explanation

• genetic vulnerability and trigger (traumatic event) needed

Polygenic criticism of Genetic Explanation

• well established genes are involved

• not pinned down exact genes

• many genes involved and only increase risk by a bit

• limits usefulness of explanation as cannot identify individuals at greater risk

Neural Explanation of OCD

• abnormally low serotonin - mood info

• abnormally high dopamine - linked to compulsions

• abnormal brain circuits and structures

• atypical functioning of lateral frontal lobes - logic and decision making

• hyperactivity in basal ganglia - repetitive motor movements explaining compulsions

Anti-Depressant strength of Neural Explanation

• anti-depressants that work on serotonin reduce OCD symptoms effectively

• supports the idea that serotonin is involved in OCD

• it might be too low in someone with OCD

Correlation and Causation criticism of Neural Explanation

• difficult to establish causation because it's a correlational relationship between low serotonin and OCD

• cant conclude cause and effect as it could be the OCD that causes low serotonin

• direction of causality cant be established

• or third variable causing both OCD and low serotonin levels

Biological Treatment for OCD

• drug therapy

• OCD could cause lower levels of serotonin

• drugs used to increase available serotonin at post-synaptic neurone

• selective serotonin reuptake inhibitors (SSRI)

• used to treat OCD

• 3-4 months daily for SSRI to impact symptoms

OCD Patient without SSRI

• serotonin released from pre-synaptic neurone

• diffuses across synaptic gap

• binds to receptors on post-synaptic neurone

• serotonin reabsorbed by receptor ports

OCD Patient taking SSRI

• SSRI block re-uptake of serotonin

• serotonin remains active at receptor sites

• continue to bind to receptors

• increases serotonin activity

Effective strength of Drug Therapy

• Soomro reviewed 17 studies comparing SSRI and placebo

• as treatment of OCD

• studies better results for SSRI than placebo up to 3 months

• drug therapy reduction in symptoms improving life

Effort strength of Drug Therapy

• little input from user in time and effort

• less disruptive to patient life

• suits children and severe symptoms

• severity may not be able to access or engage in psychological therapies

Side Effect criticism of Drug Therapy

• SSRI can cause side effects e.g. nausea, headaches, insomnia

• more than 1/10 patients suffer weight loss

• 1/100 become aggressive and suffer disruption to blood pressure and heart rhythm

• lead to patients stop taking them so not effective

Trigger criticism of Drug Therapy

• doesn’t treat underlying cause

• can be response to traumatic life event

• drugs do not address trauma that psychological therapies would

• drugs only effective whilst being taken as no trauma is addressed/resolved