obsessive compulsive disorder

obsessive

a persistent thought,idea or impulse that is experienced repeatedly,feels intrusive and causes anxiety

compulsion

repetitive and rigid behaviour or mental act that a person feels driven to perform in order to prevent or reduced activity

DSM - 5 categories of OCD

OCD - characterised by obsession and compulsions

trichoillomania - compulsive hair pulling

hoarding disorder - the compulsive gathering of possessions and the inability to part with anything regardless of its value

excoriation - compulsive skin pulling

repetitive behaviour accompanied by obsessive thinking

main symptoms of OCD

recurrent obsessions and compulsions

recognition by the individual that the obsession and compulsions are excessive or unreasonable

the person is distressed or impaired and daily life is disrupted by the obsessions and compulsions

cycle of OCD

obsessive thought - anxiety - compulsive behaviour - temporary relief

biological approach

a perspective that emphasises the importance of physical processes in the body such as genetic inheritance and neutral function

genetic explanations

Genes makes up chromosomes and consist of of DNA which codes for the physical features of an organism and psychological features

genes are transmitted from parent to offspring

neural explanations

the view that physical and psychological characteristics are determined by the behaviour of the nervous system, in particular the brain as well as individual neurons

Genetics

It has been proposed that there is a genetic component to OCD which predisposes some individuals to the illness.

The genetic explanation suggests that whether a person develops OCD is at least partly due to their genes.

This may explain why patients often have other family members with OCD.

Bellodi et al (2001)

claim that genetic factors play a role in the disorder.

Using evidence from twin studies and family studies, they showed that close relatives are more likely to have the disorder than more distant relatives.

Mckeon and Murray

patients with OCD are more likely to have first degree relatives who suffer from anxiety disorders.

Pauls et al

there is a much higher percentage of OCD sufferers in relatives of patients with OCD than in the control group without OCD.

polygenic

this means that its development is not determined by a single gene but a few – this means that there is little predictive power from this explanation.

diathesis–stress model

• The diathesis–stress model suggests that people gain a vulnerability towards OCD through genes but an environmental stressor is also required.

• This could be a stressful event, for example a bereavement.

candidate genes

researchers have identified genes,which create vulnerability for OCD which are called candidate genes

some of these genes are involved in regulating the development of the serotonin system

neutral explanations

the genes associated with OCD are likely to affect the levels of key neurotransmitters as well as structures of the brain

rapport and wise

proposed the hypersensitivity of the basal ganglia gives a rise to the repetitive motor behaviours seen in OCD

thalamus

brain area whose functions include cleaning, checking and other safety behaviours

An overactive thalamus would result in an increased motivation to clean or check for safety.

If the thalamus was overactive the OFC would also become overactive as a result.

OFC (The orbital frontal cortex)

involved in decision making and worry about social and other behaviour. In OCD the OFC is believed to be overactive.

An overactive OFC would result in increased anxiety and increased planning to avoid anxiety.

drug therapy

in mental disorders aims to increase or decrease levels of neurotransmitters in the brain to increase or decrease their activity

SSRI (Selective Serotonin Reuptake Inhibitors)

SSRIs work on increasing certain neurotransmitter in the brain by preventing the re-absorption of serotonin.

By preventing the re-absorption of serotonin, SSRIs effectively increase its levels in the synapse and thus continue to stimulate the post-synaptic neuron

Combining SSRIs with other treatment

Drugs are often used alongside cognitive-behavioural therapy (CBT)

The drugs reduce the sufferer’s emotional symptoms, such as anxiety or depression

This means that the patient can then engage more effectively with CBT

Some sufferers may respond best to CBT alone without the need for medication

strengths of drug therapy

Drug therapy is effective at tackling OCD symptoms

Drugs are cost-effective and non-disruptive

Drugs can have side-effects

limitations of drug therapy

Unreliable evidence for drug treatments

Some cases of OCD follow trauma