Obsessive Compulsive Disorder (OCD) + Biological Approach

Obsessive Compulsive Disorder (OCD)

A mental disorder characterised by obsessions (uncontrollable, intrusive thoughts, images or urges) and/or compulsions (repetitive, ritualistic behaviours or mental acts). It affects people differently but the common pattern is: Obsession, Anxiety, Compulsion and Temporary Relief.

Obsession(s) - OCD

Uncontrollable, intrusive thought, image or urge that enters the mind. This is always unpleasant and are persistent/recurrent. First stage in common OCD pattern. Some people with OCD only experience obsession.

Anxiety - OCD

An emotional characteristic of OCD. Overwhelming anxiety is provoked by obsession (which is unpleasant) as they are often frightening and disturbing. Reduced by compulsions.

Compulsion(s) - OCD

Repetitive + ritualistic behaviours or mental acts which sufferers are driven to perform in order to reduce anxiety caused by obsession. Compulsions are either not realistically connected to anxiety they are trying to neutralise or clearly obsessive. Sufferers are aware compulsions are inappropriate but are unable to control them. They significantly interfere with a sufferers normal life.

(Temporary) Relief - OCD

Result of the compulsion. It temporarily relieves anxiety - this strengthens the behaviour of the compulsion through positive reinforcement. This is why those with OCD often give into their compulsions - it is easiest and most comfortable to stop anxiety.

Examples of OCD obsessions

Fear of causing or failing to prevent harm (will cause a fire if don’t check power switches), fear of contamination (unable to touch surfaces in public bathrooms), fears relating to order or symmetry (only eats foods in certain order cut in certain ways), intrusive violent/sexual/religious thoughts images or urges (desire to kill an ex or family member)

Examples of OCD compulsions

Excessive washing of hands or body (must shower twice), excessive cleaning of clothes or home (can’t leave house until every surface is clean), checking locks, light switches, handles etc, ordering + arranging items, counting, saying specific words or phrases, asking for reassurance.

Avoidance - OCD behaviour

Sufferers tend to avoid situations that are likely to trigger obsessions. This avoidance interferes significantly with the sufferers normal routine and life. (eg. a sufferer with obsessions about contamination will avoid situations that involve coming into contact with germs

Biological approach - Genetic explanation for OCD

The Biological approach suggests that OCD has a physical cause. One way it tries to explain this is through genes. The genetic explanation uses: family studies, twin studies and studies of individual genes; to try and explain/suggest that inherited genes cause OCD. This is a reductionist approach and does not consider how lived experiences can impact a mental disorder, like OCD,’s development. It only considers physical causes.

Genetic Explanation - Family Studies

Family studies have established that OCD is more common among Biological relatives of an individual with OCD. Lewis’s research showed that siblings (of an individual with OCD) have a 21% risk of developing OCD and parents (of an individual with OCD) had a 31% risk of developing OCD - this is comparatively large to the general risk of 2% which suggests OCD runs in families

Genetic Explanation - Twin Studies

Found that Monozygotic twins are more concordant for OCD than Dizygotic twins (assumedly due to genetic factors). A Meta-Analysis study found the concordance rate for OCD in MZ twins ways 68%, whereas the concordance rate in DZ twins was only 31%. Therefore, this partially suggests that genes cause OCD as MZ with 100% same genes were more likely to develop OCD, HOWEVER it is not a complete explanation as genes cannot be the only factor determining if OCD is developed as then all MZ Twins would have a 100% concordance rate for developing OCD.

Genetic Explanation - Studies of Individual Genes

There is evidence that there are up to 230 candidate genes for OFC. This means OCD is polygenic (unrelated to a single genes, and a number of different genes confer a small increased risk of developing the disorder). OCD is also aetiologically heterogeneous (this means thar different combinations of genes can lead to the condition - every individual with OCD has a different combination of genes that led to it). There is no one gene that causes OCD, but many that mean it could potentially be developed - this perhaps suggests by OCD is so varied in its presentation in individuals.

Candidate Genes

Genes related to the development of a mental disorder/disorder - in this case OCD. Research suggests there are up to 230 Candidate genes for OCD

Polygenic

When a disorder (eg OCD) is unrelated to a single gene but a number of different genes confer a small increased risk.

Aetiologically Heterogeneous

A disorder (eg OCD) that can be led to/caused by different combinations of genes. There are multiple gene combinations that can cause OCD to develop in an individual.

Genetic Explanation - Con - Twin Studies

One Weakness of the genetic explanation for OCD is that twin studies prove it is not a purely genetic disorder. As the concordance rates for OCD in MZ Twins (which have 100% same genes) are not 100% this suggests OCD cannot be inherited purely by having the genes for its development. The Diathesis model explains this but suggesting individuals inherit a susceptibility to developing OCD through their genes, but the disorder will only develop is an individual is exposed to stress. Research supports this as in a study over half the patients with OCD had a traumatic event in their past and OCD was more severe in patients with multiple traumas. Therefore, genetics cannot offer a complete explanation for OCD development.

Genetic Explanation - Con - Family Studies

One weakness of the Genetic explanation is the use of family studies to support it as they do not prove genes cause OCD. Many researchers now accept the fact that OCD runs in families and may be more to do with common rearing patterns or environmental patterns than with heredity. Therefore, family studies lack internal validity, so they are weak evidence for the genetic explanation.

Genetic Explanation - Pro - Research

One strength of the genetic explanation is that research gives evidence that there is a clear relationship between genes and OCD development. Twin studies suggest that there is a relationship between genes and OCD as there is a higher level of congruence for OCD in MZ twins than DZ twins. Therefore, having specific genes means OCD is more likely to develop.

Neural Explanation - OCD

Suggests OCD is caused by abnormal levels of neurotransmitters in the brain (in OCD this is abnormally high levels of dopamine and abnormally low levels of serotonin) and abnormal brain structures (in OCD this is in the frontal lobes and also evidence that the left parahippocampal gyrus there is abnormal function).

Neural explanation - OCD - Neurotransmitters

OCD has been related to abnormally high levels of dopamine and abnormally low levels of serotonin. It is unclear if these levels of neurotransmitters are the cause of OCD or a consequence of it. Many genes studied in relation to OCD are associated with the action of neurotransmitters.

Neural explanation - OCD - brain structures

OCD is associated with abnormal functioning in the frontal lobes (which are involved in thinking and decision making) as well as some evidence that abnormal functioning occurs in the left parahippocampal gyrus (which is associated with processing unpleasant emotions).

Neural Explanation - Pro - Link

One strength of the neural explanation for OCD is that there is evidence to support the link between abnormal levels of neurotransmitters and OCD. For example, one study found that animals given drugs to increase levels of dopamine began to exhibit behaviours resembling those found in OCD patients. Moreover, when OCD patients are given drugs to increase serotonin levels this reduced their OCD symptoms. Therefore, this research combined suggests that abnormally high levels of dopamine and abnormally low levels of serotonin are related to OCD.

Neural Explanation - Con - Consequence?

One weakness of the neural explanation for OCD is that we cannot be certain that abnormal functioning of brain structures and neurotransmitters causes OCD. It is possible that these abnormalities are a consequence of OCD as evidence only suggests there is a link between the abnormalities and OCD. Therefore, the neural explanation of OCD is weak.