biological approach to explaining OCD

What is the basic genetic explanation

What study was done to support this

OCD is inherited from your parents through genes

When looking at patients with OCD it is commmonn to look at first degree relatives to see if they have ocd

siblinsg or parents or children

LEWIS found that 37% of his ocd patients had a parent with OCD and 21% had a sibling with OCD

Strongly suggest OCD is run through families and at least partly is caused by genes

How does rh cognitive approach explain OCD

Explains it through the faulty thoughts a person with OCD has

RACHMAN AND HODGES

The cognition of ocd patients were increased and took place i the frontal cortex

This shows the explanation could be a combination of biology of the brain and the obsessions of the patient

Competing explanations- diathesis stress hypothesis is best suited where there is a genetic risk and interacts with the environment and the learning and cognitions which then play a role in the specific symptoms the patient suffers from

What is the gene that runs though families with OCD that involves seretonin

SERT gene

A faulty copy involves serotonin to be re absorbed too quickly back into the nervous system

Can’t perform its job - doesn’t block impulsive messages

What is the other gene

COMT

Faulty copy causes an increase in dopamine levels

In limbic system

Causes increase in anxiety

Increases obsessions a person has

A03 what did Taylor do

Taylor found that there was evidence for 230 different genes that play a role in OCD and most of them affect serotonin and dopamine levels.

Supporting the genetic explanation

What was the twins study done

NESTADT

Found that 68% of identical twins shared OCD

VS

31% of non identical twins sharing OCD

Showing that genes do play a role

Who found that it was very common for ocd to run in families (2 NAMES)

MARINI and STebnicki

Looked at how common it was for people within the same family to have OCD

Found that it does seem to run in families

What is an extension point that can be made to do with the environment

CROMER found that over half of the patients with OCD had also suffered from severe trauma

The more ever the trauma the worse the symptoms of OCD

This suggests that genes interact with the. Environment to trigger OCD and influence how severe it is

What is the basis of neural explanation

The genes associated with OCD help to maintain and control the activity of nuerotranmitters

Multiple parts of the brain has been involved in OCD and the genes interact with both the brain areas and the associated neurotransmitters

How does serotonin fit into the neural explanation and where is it located

What is the counter argument

It’s located in the frontal cortex

Linked to the inability to stop the obsessions

It helps to regulate mood and prevent impulsive messages

Some people with OCD have normal SERT genes - means there must be other ways that OCD can be caused

Where has increased levels of dopamine been found

THALAMUS

Part of the limbic system and linked to increase levels of anxiety

How dos the frontal lobe relate to OCD

Changes in the frontal lobe relate to OCD

Frontal lobe forms part of the worry circuit

If worry circuit not controlled by frontal cortex then anxious thoughts can spiral out of control

What part of the Brain has been found to function abnormally in the brain of OCD patients

PARAHIPPOCAMPUL GYRUS

Plays a role in processing unpleasant emotions

What is a study that supported the role of OCD

One of the best treatments of OCD is antidepressants which increases levels of serotonin

Nestadt - OCD symptoms is common in other illnesses which damages the neurotransmitter systems

Suggests OCD has a biological cause

What is an issue fo explanation of serotonin

50% of people with. OCD also have clinical depression which is also linked to low levels of serotonin

Therefore the serotonin levels could be due to the comorbid disorder of depression and not lineked to OCD itself

What did PICHICHERO find out?

A lot of US child cases of OCD

Children infected with strep throat shortly before

These children also developed Tourette’s which is a separate disorder but affects the same parts of the brain to OCD

Suggests that damage to the nervous system by a virus can explain OCD

What is the study to do with Lyme disease

FALLON and NIELD

40% of people who were infected with Lymes disease went on to suffer from neural damage which resulted in OCD

What is a problem with the biological explanation for OCD

A lot fo the research is based on correlation

Can only talk about links and not cause and effect about biology and OCD

But it would be unethical to run experiments investigating how damage to the brain can cause OCD and investigate the neurotransmitters involved as it can cause harm to the patient

What did Koran do

Koran suggest that the drug treatment only lasts 3-4 months which is to long enough to fully asses if the drug has treated OCD

What did MAINA do

MAINA found that patients relapsed within a few weeks of the medication stopping

Drugs are only treating the symptoms of OCD and not the actual cause

Why is it hard for doctors to choose the right treatment

There is a publication bias where GOLDACRE found that it was particularly true for antidepresssants wher only the good results were published

If a drug doesn’t have an effect its not published

Positive impacts of antidepressants may be overstated

Makes it hard for doctors to prescribe the most suitable treatment

SNRIS WHAT ARE THYE

Serotonin noradrenaline reuptake inhibitors

SNRIs increase the amount of serotonin and noradrenaline and is used for patients who can’t handle SSRIS or they weren’t effective

LUGO RADILLO

Found psilocybin as a way that reduces OCD symptoms in a case study

The use of PSILOCYBIN needs more research but is ana other native tot hose who cant take SSRI SNRI

How do anti anxiety medication work and what is a study that shows a downside of it

Anti anxiety drugs like VALIUM or XANAX

Work by increasing the amounts of GABA in the brain

Neurotransmitter GABA slows down the activity within brain

Reduce anxiety and therefore control obsessions and associated compulsions

However ASHTON found that BZs have legates risk of addiction and should only be used fo shot periods

What happens during brain surgery

Risk are much higher

An electrode is implanted in the caudate nucleus and it increase the ability to control the anxiety and therefore the worry circuit which goes from the caudate nucleus and into the limbic system

What is the psychological treatment

Behavioural treatment focuses on classical conditioning and operant to reduce the strength of obsessions and compulsions

ERP theraoy is used (exposure and response prevention)

Obsession is triggered but the patient is stopped from carrying out the compulsions which helps

ABUCHER found that it was highly effective

What else has been used and why

CBT

NICE COMITTE found that 75% of patients are helped using CBT

Recommend that a combination of OCD and medication is used as the fastest and most effective way to alleviate the symptoms

Suggest biological approach isn’t the only way to treat OCD