Psychopathology:Psychopathology:

Biological explanations of Biological explanations of OCDOCD

What are the characteristics of What are the characteristics of someone with Obsessive-compulsive someone with Obsessive-compulsive

disorder (OCD)?disorder (OCD)? OCD is an anxiety disorder. OCD is an anxiety disorder.

The behaviours are The behaviours are ritualistic, (hand washing, ritualistic, (hand washing, constant checking) and is constant checking) and is therefore is the source of therefore is the source of great anxiety.great anxiety.

Interestingly the disorder Interestingly the disorder is equally common in both is equally common in both men and women and the men and women and the onset of the behaviour is onset of the behaviour is usually in young adult life.usually in young adult life.

Again you could think of Again you could think of the disorder as having two the disorder as having two componentscomponents

Obsessions.Obsessions.

Compulsions.Compulsions.

ObsessionsObsessions – recurrent, intrusive thoughts – recurrent, intrusive thoughts or impulses that are perceived as or impulses that are perceived as inappropriate, grotesque or forbidden (DSM-inappropriate, grotesque or forbidden (DSM-IVR).IVR).

The obsessions generally cause anxiety as The obsessions generally cause anxiety as they are unlike the sufferers typical they are unlike the sufferers typical thoughts. These thoughts are believed to be thoughts. These thoughts are believed to be uncontrollable, the sufferer feels as though uncontrollable, the sufferer feels as though they may lose control and act upon these they may lose control and act upon these obsessions. The most common obsessions obsessions. The most common obsessions take the form of take the form of

DOUBTS IMPULSES IMAGES.DOUBTS IMPULSES IMAGES.

CompulsionsCompulsions – Repetitive acts that work to – Repetitive acts that work to reduce anxiety of the sufferer by preventing reduce anxiety of the sufferer by preventing some dreaded event happening (DSM-IVR).some dreaded event happening (DSM-IVR).

These behaviours can be ‘hidden’ i.e. mental These behaviours can be ‘hidden’ i.e. mental acts or overt i.e. hand washing. acts or overt i.e. hand washing.

The vast majority of sufferers realise their The vast majority of sufferers realise their behaviour is irrational but feel compelled to behaviour is irrational but feel compelled to perform the given behaviour for fear of perform the given behaviour for fear of something terrible occurring, thus the something terrible occurring, thus the behaviour also create anxiety.behaviour also create anxiety.

What are the characteristics of What are the characteristics of someone with Obsessive-someone with Obsessive-

compulsive disorder (OCD)?compulsive disorder (OCD)? A diagnosis is given if the sufferer fits the A diagnosis is given if the sufferer fits the

following criteria:following criteria:

Recurrent Recurrent persistent thoughts, impulses or persistent thoughts, impulses or images that feel intrusive and inappropriate, and images that feel intrusive and inappropriate, and cause excessive anxiety or distress.cause excessive anxiety or distress.

The sufferer partakesThe sufferer partakes in regular repetitive in regular repetitive behaviour behaviour

(hand washing). The behaviour must not be related (hand washing). The behaviour must not be related in anyway to what they are designed to prevent.in anyway to what they are designed to prevent.

The individual recognisesThe individual recognises the behaviour is the behaviour is excessive and product of their own mind.excessive and product of their own mind.

Biological explanations Biological explanations of OCD.of OCD.Genetic Factors Genetic Factors

(A01)(A01)Family/Twin Studies-Family/Twin Studies- Nestadt et al (2000) 80 Nestadt et al (2000) 80

patients with OCD & 343 of their near patients with OCD & 343 of their near relatives compared with 73 control patients relatives compared with 73 control patients without mental illness & 300 of their without mental illness & 300 of their relatives. Strong link with near family (5x relatives. Strong link with near family (5x greater risk if had first degree relative).greater risk if had first degree relative).

Meta-analysis of 14 twin studies found on Meta-analysis of 14 twin studies found on average MZ twins 2x more likely to develop average MZ twins 2x more likely to develop the disorder if their co-twin had it than DZ the disorder if their co-twin had it than DZ twins.twins.

COMT gene COMT gene COMT helps to reduce the action COMT helps to reduce the action of dopamine. The variation in the COMT of dopamine. The variation in the COMT gene decreases the amount of COMT gene decreases the amount of COMT available and therefore dopamine is not available and therefore dopamine is not controlled and there is probably too much. controlled and there is probably too much. Researchers collected DNA samples from Researchers collected DNA samples from 73 people with OCD and 148 who did not 73 people with OCD and 148 who did not have a mental disorder. The variation in the have a mental disorder. The variation in the gene occurred in nearly half of the men gene occurred in nearly half of the men with OCD but only 10% of women with with OCD but only 10% of women with OCD. It was found in about 17% of those OCD. It was found in about 17% of those with good mental health.with good mental health.

..

Evaluation of genetic Evaluation of genetic factors (AO2)factors (AO2)

+ Concordance rates for twin studies generally high compared + Concordance rates for twin studies generally high compared with other disorders (e.g.. 87%)with other disorders (e.g.. 87%)

+The OCD symptoms of parents and their children are often +The OCD symptoms of parents and their children are often different which suggests the disorder is not learned.different which suggests the disorder is not learned.

-However, concordance rates are never 100% which means -However, concordance rates are never 100% which means that OCD is not entirely genetic.that OCD is not entirely genetic.

+ COMT gene- study by Schindler confirmed association but + COMT gene- study by Schindler confirmed association but didn’t find gender differences found previously. didn’t find gender differences found previously.

-Research rarely replicated as this is a new area-Research rarely replicated as this is a new area+/-Other genes being discovered all the time – unlikely to be +/-Other genes being discovered all the time – unlikely to be

just one gene.just one gene.- Studies before 1990 difficult to interpret due to differences - Studies before 1990 difficult to interpret due to differences

in diagnostic criteria.in diagnostic criteria.-Problems with twin studies – they may not be truly identical. -Problems with twin studies – they may not be truly identical.

Problems with bias in diagnosis.Problems with bias in diagnosis.-Difficulties in separating effects of environment and genetics.-Difficulties in separating effects of environment and genetics.

Biochemical FactorsBiochemical Factors(AO1)(AO1)

SerotoninSerotonin – Lower levels of serotonin – Lower levels of serotonin found in OCD sufferers .found in OCD sufferers .

DopamineDopamine levels are thought to be levels are thought to be abnormally high in people with OCD- abnormally high in people with OCD- thus suggesting other thus suggesting other nneurotransmitters are involved in OCD. eurotransmitters are involved in OCD.

Evaluation of Evaluation of biochemical factorsbiochemical factors+Studies using drugs have shown a reduction in dopamine +Studies using drugs have shown a reduction in dopamine

levels is positively correlated with a reduction in OCD levels is positively correlated with a reduction in OCD symptoms.symptoms.

+Experiments which inject animals with drugs that increased +Experiments which inject animals with drugs that increased levels of dopamine have caused the animals to levels of dopamine have caused the animals to demonstrate OCD type behaviours.demonstrate OCD type behaviours.

+Drugs that increase serotonin (anti depressants have been +Drugs that increase serotonin (anti depressants have been shown to reduce OCD symptoms.shown to reduce OCD symptoms.

- But research results relating to serotonin are varied – - But research results relating to serotonin are varied – sometimes symptoms have been made worse. There is a sometimes symptoms have been made worse. There is a great deal of contradictory research.great deal of contradictory research.

- Drugs seem to show only partial alleviation of the symptoms - Drugs seem to show only partial alleviation of the symptoms so the process is not fully understood. The exact function so the process is not fully understood. The exact function of neurotransmitters in the development of OCD is far of neurotransmitters in the development of OCD is far from understood.from understood.

-Cause or effect- it may be that neurotransmitter levels -Cause or effect- it may be that neurotransmitter levels fluctuate as a result of OCD rather than as a cause of it.fluctuate as a result of OCD rather than as a cause of it.

NeuroanatomyNeuroanatomy

Brain DysfunctionBrain Dysfunction Basal Ganglia –abnormalities in prefrontal Basal Ganglia –abnormalities in prefrontal

cortex where thinking and judgement takes cortex where thinking and judgement takes place is often present in OCD sufferers. place is often present in OCD sufferers.

OCD is often found in cases of Tourette’s and OCD is often found in cases of Tourette’s and Parkinson’s disease which are all disorders Parkinson’s disease which are all disorders in which the basal ganglia is implicated.in which the basal ganglia is implicated.

Basal ganglia damage resulting from head Basal ganglia damage resulting from head injuries can also cause OCD.injuries can also cause OCD.

Surgery which disconnects the basal ganglia Surgery which disconnects the basal ganglia from the frontal cortex can reduce from the frontal cortex can reduce symptoms of severe OCD symptoms of severe OCD

NeuroanatomyNeuroanatomy

Brain DysfunctionBrain Dysfunction Another area implicated is the OFC Another area implicated is the OFC

circuit. The OFC sends ‘worry’ signals. circuit. The OFC sends ‘worry’ signals. These signals are normally suppressed These signals are normally suppressed by the caudate nucleus. In OCD the by the caudate nucleus. In OCD the caudate nucleus is thought to be caudate nucleus is thought to be damaged so it cannot suppress the damaged so it cannot suppress the signals which become increasingly signals which become increasingly excited – increasing compulsive excited – increasing compulsive behaviour and anxiety.behaviour and anxiety.

Evaluation of neuroanatomy Evaluation of neuroanatomy explanationexplanation

Basal ganglia and OFC:Basal ganglia and OFC:+Neuro imaging studies have shown increased activity +Neuro imaging studies have shown increased activity

in basal ganglia in OCD sufferers.in basal ganglia in OCD sufferers.- However results of neuro imaging studies have been - However results of neuro imaging studies have been

inconclusive and basal ganglia impairment has not inconclusive and basal ganglia impairment has not been found in all OCD patients.been found in all OCD patients.

+ Scans show increased activity in OFC in OCD patients.+ Scans show increased activity in OFC in OCD patients.+ It has been demonstrated that OFC damage caused by + It has been demonstrated that OFC damage caused by

head injury, viruses and tumours can give rise to OCD.head injury, viruses and tumours can give rise to OCD.

+ Menzies (2007) supported both neuroanatomical and + Menzies (2007) supported both neuroanatomical and genetic explanations – make notes on the study (207)genetic explanations – make notes on the study (207)

Evaluation of biological Evaluation of biological explanationsexplanations

Promising research but cannot yet Promising research but cannot yet offer a complete explanation.offer a complete explanation.

One of most powerful challenges to One of most powerful challenges to this view is that PSYCHOLOGICAL this view is that PSYCHOLOGICAL interventions show a strong interventions show a strong therapeutic effect and yet do not rely therapeutic effect and yet do not rely on drugs or make any physical on drugs or make any physical intervention.intervention.

Examination questions on Examination questions on biological explanations:biological explanations:

January 2010January 2010 Outline one biological and one psychological explanation for Outline one biological and one psychological explanation for

obsessive compulsive disorder (9)obsessive compulsive disorder (9) Evaluate explanations for obsessive compulsive disorder (16) Evaluate explanations for obsessive compulsive disorder (16)

June 2010June 2010

Not examined -Psychological therapies and clinical characteristicsNot examined -Psychological therapies and clinical characteristics

January 2011January 2011

Psychological explanations Psychological explanations of OCDof OCD

PsychodynamicPsychodynamicFreud –OCD arises when unacceptable wishes and impulses Freud –OCD arises when unacceptable wishes and impulses

from the ID are only partially repressed and so provoke from the ID are only partially repressed and so provoke anxiety. The use of ego defence mechanisms reduce the anxiety. The use of ego defence mechanisms reduce the anxiety. The 3 most common defences in terms of OCD are:anxiety. The 3 most common defences in terms of OCD are:

iisolationsolation ( people attempt to isolate themselves, or disown ( people attempt to isolate themselves, or disown undesirable thoughts and impulses. When the forces of the undesirable thoughts and impulses. When the forces of the ID dominate, the impulses intrude as obsessional thoughts.ID dominate, the impulses intrude as obsessional thoughts.

uundoingndoing ( when isolation fails the second defence of ( when isolation fails the second defence of ‘undoing’ produces compulsive acts-washing away ‘undoing’ produces compulsive acts-washing away unacceptable impulses) unacceptable impulses)

reaction formationreaction formation (taking on traits that are opposite to the (taking on traits that are opposite to the unacceptable impulses-such as compulsive kindness may unacceptable impulses-such as compulsive kindness may be a way of countering unacceptable aggressive impulses.)be a way of countering unacceptable aggressive impulses.)

Psychodynamic-AdlerPsychodynamic-Adler

Inferiority complex explanation-Inferiority complex explanation- Some parents dominate their children and Some parents dominate their children and

prevent them from developing a sense of their prevent them from developing a sense of their own competence. When this happens an own competence. When this happens an inferiority complex may result so that later, as inferiority complex may result so that later, as adults, these people may adopt compulsive adults, these people may adopt compulsive rituals such as tidying out drawers, in order to rituals such as tidying out drawers, in order to carve out an area in which they exert control of carve out an area in which they exert control of something and can feel competent.something and can feel competent.

Psychological explanations Psychological explanations of OCDof OCD

+ + Freud used the evidence of Rat Man to Freud used the evidence of Rat Man to support his explanationssupport his explanations

- Some researchers have suggested that Some researchers have suggested that the therapy developed by Freud the therapy developed by Freud (Psychoanalysis) may have a negative (Psychoanalysis) may have a negative effect on OCD recovery.effect on OCD recovery.

- -Difficult to test the idea of unconscious -Difficult to test the idea of unconscious motivations. No convincing evidence to motivations. No convincing evidence to support the PD view of OCD and support the PD view of OCD and psychoanalysis has been of little help in psychoanalysis has been of little help in helping people to overcome OCD.helping people to overcome OCD.

Psychological explanations of Psychological explanations of OCD.OCD.

Behavioural Behavioural Mowrer suggested that the learning of Mowrer suggested that the learning of

fears is a two step process:fears is a two step process:Classical conditioningClassical conditioning A neutral stimulus A neutral stimulus

becomes associated with anxiety through becomes associated with anxiety through Classical Conditioning.Classical Conditioning.

Operant conditioningOperant conditioning Any action that Any action that enables the individual to avoid a enables the individual to avoid a negative event is negative negative event is negative reinforcement. Avoidance of the fear reinforcement. Avoidance of the fear leads to positive outcomes and is leads to positive outcomes and is therefore reinforced.therefore reinforced.

Thus the compulsive behaviour Thus the compulsive behaviour becomesbecomes a way of establishing a way of establishing control and reducing anxiety- and as control and reducing anxiety- and as a result the behaviour is reinforced a result the behaviour is reinforced and the behaviour may become and the behaviour may become compulsive whenever the individuals compulsive whenever the individuals face thoughts that provoke anxiety.face thoughts that provoke anxiety.

Psychological explanations of Psychological explanations of OCD.OCD.

Behavioural evaluation AO2Behavioural evaluation AO2+ Researchers thought that if Mowrer was right, that OCD patients are predisposed to more rapid conditioning. Research did support this finding, OCD patients were conditioned more rapidly.

+Further research (Rachman) has shown that compulsions do relieve the anxiety of obsessional thoughts. In a series of experiments OCD patients were asked to carry out some ‘prohibited’ activity such as touching something dirty. Patients were then allowed to carry out their compulsion (showed reduction in anxiety). If however they were asked to delay carrying out their compulsive activity their anxiety levels were found to persist for a while then gradually decline. Compulsions therefore provide a quicker relief from anxiety.

+ This theory has led to development of a reasonably effective therapy –ERP.

- Theory does not explain the CAUSE of the obsessive thoughts, it explains how they are maintained. (e.g. aspirins might cure headaches but headaches are not due to lack of aspirin in the body!)

Cognitive explanations of Cognitive explanations of OCDOCDCognitive:

Everyone has unwanted or intrusive thoughts from time to time but these thoughts can be ignored or dismissed fairly easily.

For some people irrational thoughts cannot be ignored and feel overwhelming leading to the expectation that terrible things will happen.

The thoughts continue because the person cannot ignore them.

This is also because they often have depression. In order to avoid the consequences of these thoughts

the sufferer must ‘neutralise’ them. This only provides temporary relief and then the anxiety builds up again.

Over time people become more convinced that these thoughts are dangerous and they become obsessions.

The need to reduce the anxiety they cause becomes a becomes a compulsion.compulsion.

Evaluation of cognitive Evaluation of cognitive explanations of OCDexplanations of OCD

+ Research has supported the idea that people with + Research has supported the idea that people with OCD have different patterns of thinking, such as OCD have different patterns of thinking, such as believing that they should have total control over believing that they should have total control over their world.their world.

+Research has also shown that people with OCD have +Research has also shown that people with OCD have more intrusive thoughts than ‘normal’ people.more intrusive thoughts than ‘normal’ people.

+The Rachman research also supports the cognitive +The Rachman research also supports the cognitive explanation as well as the behavioural explanation.explanation as well as the behavioural explanation.

+ CBT therapies have been shown to be reasonably + CBT therapies have been shown to be reasonably effective in treating OCD.effective in treating OCD.

-the theory is more descriptive than explanatory – why -the theory is more descriptive than explanatory – why do people develop OCD in the first place? We all do people develop OCD in the first place? We all have intrusive thoughts but don’t all get OCD.have intrusive thoughts but don’t all get OCD.

ConclusionConclusion

No single explanation can account for a complex No single explanation can account for a complex disorder like OCDdisorder like OCD

Likely to be an interaction between biological, Likely to be an interaction between biological, psychological and social factors.psychological and social factors.

Diathesis stress model- certain individuals have an Diathesis stress model- certain individuals have an underlying biological predisposition to OCD. This underlying biological predisposition to OCD. This may develop fully in response to environmental may develop fully in response to environmental triggers. triggers.