Psychopathology - The Biological Approach to OCD

Question 1

What are the behavioural factors of obsessive-compulsive disorder?

Answer 1

• Compulsions: Actions that are carried out repeatedly, e.g. handwashing. The same behaviour is repeated in a ritualistic way to reduce anxiety. 10% of sufferers only have compulsions, they have no obsessions, just irrationality. It relieves the anxiety caused by obsession.
• Avoidance: The OCD is managed by avoiding situations that trigger anxiety, e.g. sufferers who wash repeatedly may avoid coming into contact with germs.

Question 2

What are the emotional factors of obsessive-compulsive disorder?

Answer 2

• Anxiety and distress: Obsessive thoughts are unpleasant and frightening, and the anxiety that goes with these can be overwhelming.
• Depression: Often accompanies OCD. Anxiety leads to low mood and a lack of or barrier to activities previously enjoyed.
• Guilt and disgust: Irrational guilt, for example over a minor moral issue, or disgust which is directed towards oneself or something external like dirt.

Question 3

What are the cognitive factors of obsessive-compulsive disorder?

Answer 3

• Obsessive thoughts: About 90% of OCD sufferers have obsessive thoughts which are negative, e.g. recurring intrusive thoughts about being contaminated by dirt or germs.
• Insight into excessive anxiety: Awareness that thoughts and behaviour are irrational. In spite of this, sufferers experience catastrophic thoughts and are hypervigilant, i.e. ‘over-aware’ of their obsession.

Question 4

What is OCD?

Answer 4

A condition which is concerned with obsessions and/or compulsive behaviour. It is associated with anxiety and irrational thought processes.

Question 5

What is the difference between obsessions and compulsions?

Answer 5

An obsession is a cognition – take place in the mind.

A compulsion is a behaviour – something you do.

Question 6

What 4 categories do people experience OCD in?

Answer 6

• cleaning and contamination
• symmetry and ordering
• forbidden, harmful, or taboo thoughts
• impulses

Question 7

Do OCD sufferers recognise that their thoughts and behaviour are irrational?

Answer 7

OCD sufferers generally have very good insight into the fact that their thoughts and behaviour are irrational. It is important for a diagnosis of OCD that they are aware that their obsessions and compulsions are irrational.

Question 8

What is psychosis?

Answer 8

Psychotic conditions are characterised by delusions, irrational beliefs, and hallucinations - sensory experiences of things that are not there (most commonly hearing voices).

Question 9

What are the key points of the biological approach?

Answer 9

• Our behaviour is determined by our biology.

- Concerned with genetic inheritance, neural pathways and hormones.

Question 10

What are genetic explanations?

Answer 10

• Genes make up chromosomes, which create DNA.
• DNA is the genetic basis and inherited from parents.
• Determines height, hair and eye colour.
• Some psychological disorders can be inherited.
• SERT gene seems to be mutated in individuals with OCD.

Question 11

What are neural explanations?

Answer 11

• Physical and psychological characteristics are determined by neural behaviours.

Question 12

What is genetic vulnerability?

Answer 12

The inherited characteristics passed on from parents to children make it more likely that a person will develop the disorder or behaviour, but doesn’t determine it.

They are not a direct cause as other factors can trigger the disorder. Evidence for this is that the concordance rates are not 100%, which shows that OCD is due to an interaction of genetic and other factors.

Question 13

What is the diathesis-stress model?

Answer 13

A disorder or behaviour is the result of an interaction between genetic vulnerability and stress, usually caused by life events and factors.

Question 14

What are candidate genes?

Answer 14

Researchers have identified specific genes which create a vulnerability for OCD, called candidate genes.

• Serotonin genes, e.g. 5HT1-D beta, are implicated in the transmission of serotonin across synapses.
• Dopamine genes are also implicated in OCD.

Both dopamine and serotonin are neurotransmitters that have a role in regulating mood.

Question 15

How is OCD polygenic?

Answer 15

• OCD is caused by multiple genes, not just one.
• Taylor (2013) suggested over 230 genes could be involved. However, each genetic variation only increases the chance of OCD by a fraction.
• Genes associated with the action of dopamine, serotonin and neurotransmitters are involved.
• All of these regulate mood.

Question 16

What does aetiologically heterogeneous mean?

Answer 16

One group of genes may cause OCD in one person but a different group of genes may cause the disorder in another person - known as aetiologically heterogeneous.

There is also evidence that different types of OCD may be the result of particular genetic variations such as hoarding disorder and religious obsession.

Question 17

What other explanations aside from genetic are there for OCD?

Answer 17

The OCD may be culturally rather than genetically transmitted as the family members may observe and imitate each other’s behaviour, as predicted by social learning theory.

Alternatively, family members might be more vulnerable to OCD because of the stressful environment rather than because of genetic factors.

Question 18

What effect do low levels of serotonin have?

Answer 18

Neurotransmitters are responsible for relaying information from one neuron to another.

For example, if a person has low levels of serotonin than normal, transmission of mood-relevant information does not take place and mood (and sometimes other mental processes) is affected.

Question 19

What happens if the decision-making systems in the frontal lobes are impaired?

Answer 19

Some cases of OCD, and in particular hoarding disorder, seem to be associated with impaired decision-making.

This in turn may be associated with abnormal functioning of the lateral (the side) frontal lobes of the brain.

Cavedini et al. showed that from decision making studies, that these pathways are the same that function abnormally in OCD.

The frontal lobes are responsible for logical thinking and making decisions.

Question 20

What is the parahippocampal gyrus?

Answer 20

There is also evidence to suggest that an area called the left parahippocampal gyrus, associated with processing unpleasant emotions, functions abnormally in OCD.

Question 21

What are the strengths of the biological approach to explaining OCD?

Answer 21

• there is good supporting evidence for the genetic explanation of OCD
• there is some supporting evidence for neural explanations of OCD

Question 22

What are the weaknesses of the biological approach to explaining OCD?

Answer 22

• too many candidate genes have been identified so low predictive value
• environmental risk factors are also involved
• the serotonin-OCD link may not be unique to OCD

Question 23

What evidence is there to support the genetic explanation of OCD?

Answer 23

There is evidence from a variety of sources that suggests that some people are vulnerable to OCD as a result of their genetic make-up.

For example, Nestadt et al. (2010) reviewed twin studies and found that 68% of identical twins (monozygotic) shared OCD as opposed to 31% of non-identical (dizygotic) twins. This strongly supports a genetic influence on OCD.

However, identical twins get treated more similarly than non-identical twins, so the results found could actually be a result of the environment and not genetics.

Question 24

What evidence is there to support the neural explanation of OCD?

Answer 24

Antidepressants that work purely on the serotonin system are effective in reducing OCD symptoms and this suggests that the serotonin system may be involved in OCD.

Also, OCD symptoms form part of biological conditions, such as Parkinson’s Disease (Nestasdt et al. 2010).

This suggests that the biological processes that cause the symptoms in those conditions may also be responsible for OCD.

Question 25

How does the genetic explanation to OCD provide little predictive value?

Answer 25

Twin studies strongly suggest that OCD is largely genetic, but psychologists have been less successful at pinning down all the genes involved.

One reason for this is that it appears that several genes are involved and that each genetic variation only increases the risk of OCD by a fraction.

The consequence is that a genetic explanation is unlikely to ever be very useful because it provides little predictive value.

Question 26

How are environmental risk factors also involved?

Answer 26

It is not just genes, but it seems that environmental risk factors can also trigger or increase the risk of developing OCD.

For example, Cromer et al. (2007) found that over half the OCD patients in their sample had a traumatic event in their past, and OCD was more severe in those with one or more traumas.

This supports the diathesis-stress model. Focusing on environmental causes may be more productive because we are more able to do something about these.

Question 27

Why is serotonin being linked to more than OCD a weakness?

Answer 27

Many people who suffer from OCD become depressed. Having two disorders together is called co-morbidity.

This depression probably involves (though not necessarily caused by) disruption to the serotonin system. This leaves us with a logical problem when it comes to the serotonin system as a possible basis for OCD.

It could simply be that the serotonin system is disrupted in many patients with OCD because they are depressed as well.

Question 28

How can you change the levels of neurotransmitters?

Answer 28

Drug therapy for mental disorders aims to increase or decrease levels of neurotransmitters in the brain or to increase/decrease their activity.

Low levels of serotonin are associated with OCD.

Therefore drugs work in various ways to increase the level of serotonin in the brain.

Question 29

What are SSRIs?

Answer 29

Selective serotonin reuptake inhibitors are a type of antidepressant that prevent the reabsorption and breakdown of serotonin in the brain. This increases its levels in the synapse and thus serotonin continues to stimulate the postsynaptic neuron.

This compensates for whatever is wrong with the serotonin system in OCD.

Question 30

What is a typical dosage?

Answer 30

A typical daily dose of Fluoxetine (an SSRI) is 20mg although this may be increased if it is not benefitting the patient.

It takes 3-4 months of daily use for SSRIs to impact upon symptoms.

This can be increased (e.g. 60mg a day), if this is appropriate.

Question 31

How are SSRIs combined with CBT?

Answer 31

Drugs are often used alongside cognitive behaviour therapy (CBT) to treat OCD).

The drugs reduce a patient’s emotional symptoms, such as feeling anxious or depressed. This means that patients can engage more effectively with CBT.

Question 32

What are tricyclics?

Answer 32

Tricyclics (an older type of antidepressant) are sometimes used, such as Clomipramine.

These have the same effect on the serotonin system as SSRIs but the side-effects can be more severe so it is only used in patients who do not respond to current SSRI.

Question 33

What are SNRIs?

Answer 33

In the last five years, a different class of antidepressant drugs called serotonin noradrenaline reuptake inhibitor has also been used to treat OCD.

Like tricyclics, these are a second line of defence for patients who don’t respond to SSRIs.

SNRIs increase levels of serotonin as well as noradrenaline. They also increase dopamine, a neurotransmitter released when something pleasant happens.

Question 34

What are the strengths of the biological approach to treating OCD?

Answer 34

• drug therapy is effective at tackling OCD symptoms

- drugs are cost-effective and non-disruptive

Question 35

What are the weaknesses of the biological approach to treating OCD?

Answer 35

• drugs can have side-effects
• evidence for drug treatments is unreliable
• some cases of OCD follow trauma
• treat the symptoms and not the cause

Question 36

How is drug therapy effective at tackling OCD symptoms?

Answer 36

One strength of biological treatments for OCD comes from research support for their effectiveness. Randomised drug trials compared the effectiveness of SSRIs and placebos. For example, Soomro et al. (2009) reviewed 17 studies comparing SSRIs to placebos in the treatment of OCD. All 17 studies showed significantly better results for SSRIs than for the placebo conditions.

This supports the use of biological treatments, especially SSRIs, for OCD. However, studies such as this are criticised for only concluding the short-term effectiveness of drug treatments with long-term effects still to be investigated epirically.

Effectiveness is greatest when SSRIs are combined with a psychological treatment, usually CBT.

Typically symptoms reduce for around 70% of patients taking SSRIs, the rest are helped by alternative drugs or CBT+ drugs. So drugs can help most patients with OCD.

Question 37

How are drugs cost-effective and non-disruptive?

Answer 37

One of the great appeals of using drug therapy is that it required little input from the user in terms of effort and time. In contrast, psychological therapies such as CBT require the patient to attend regular meetings and put considerable thought into tackling the problem.

Drug therapies are also cheaper for the health service because they require little monitoring and cost much less than psychological treatments. These benefits mean that drug therapies are more economical for the health service, and also more attractive to patients than psychological therapies, often making them a more popular choice all round.

Question 38

What side effects can drugs have?

Answer 38

Although drugs such as SSRIs help most people, a small minority will get no benefit. Some patients also suffer side-effects such as indigestion, blurred vision and loss of sex drive (Although these side-effects are usually temporary).

For those taking Clomipramine, side-effects are more common and can be more serious. More than 1 in 10 patients suffer erection problems and weight gain, 1 in 100 become aggressive and sugar disruption to blood pressure and heart rhythm.

In addition, there are also problems with addiction so it is recommended that benzodiazepines should only be limited to a maximum of four weeks.

Such factors reduce effectiveness because people stop taking the medication, or don’t want to take them at all.

Question 39

How is evidence for drug treatment unreliable?

Answer 39

Although SSRIs are fairly effective and any side-effects will probably be short-term, like all drug treatments, SSRIs have some controversy attached.

For example, some believe the evidence favouring drug treatments is biased because it is sponsored by drug companies who do not report all evidence (Goldacre 2013).

Such companies may try to suppress evidence that does not support the effectiveness of certain drugs to maximise their economic gain.

Question 40

How do some cases of OCD follow trauma?

Answer 40

OCD is widely believed to be biological in origin. It makes sense therefore that the standard treatment should be biological.

However, it is acknowledged that OCD can have a range of other causes, and that in some cases it is a response to traumatic life events.

It may not be appropriate to use drugs when treating cases that follow a trauma when psychological therapies may provide the best option.

Question 41

What are benzodiazepines?

Answer 41

• anti-anxiety medication
• increased the effect of the neurotransmitter GAGA (natural stress inhibition)

When a benzodiazepine binds to a receptor site, it enhances the effect of GABA. More chloride ions flood the neuron, making it even more negatively charged and less likely to fire. This means that benzodiazepines have a general quietening influence on the central nervous system. Consequently, any anxiety (which is experienced as a result of the obsessive thoughts common on OCD) is reduced.

Question 42

How do drug treatments treat the symptoms of the disorder and not the cause?

Answer 42

Drug treatments are criticised for treating the symptoms of the disorder and not the cause. Although SSRIs work by increasing the levels of serotonin in the brain, which reduces anxiety and alleviates the symptoms of OCD, it does not treat the underlying cause of OCD.

Furthermore, once a patient stops taking the drug, they are prone to relapse. Therefore, Koran et al. (2007) suggest that psychological treatments such as CBT may be a more effective long-term solution to provide a lasting treatment and a potential cure.

Question 43

What is the SERT gene?

Answer 43

• The SERT gene seems to be mutated in individuals with OCD.
• The mutation causes an increase in transporter proteins at a neuron’s membrane. This leads to an increase in the reuptake of serotonin into the neuron which decreases the level of serotonin in the synapse.