Schizophrenia

Positive SymptomsFirst Rank Symptoms • In Britain, schizophrenia is only diagnosed in the presence of one of the following ‘first rank’

symptoms (disturbances of subjective experience as reported verbally by the individual). 1) Disturbance of thought: the belief that thoughts are being inserted into the individual’s mind

from outside (thought insertion) or removed from their mind by external forces (thought withdrawal), or that their thoughts are being made known to others (thought broadcasting).

2) Hallucinations (the experience of sensory stimuli which are not present) • Auditory (the most common). ‘Voices’: offer a commentary on the individual's behaviour "he

is eating his dinner";• make disparaging remarks about him "he eats like a pig ";give him commands "put the knife

on the plate".• ‘Voices’ may be a distortion of environmental noises (fridge or radiator noises interpreted as

whispering) or projections of the individual's own thoughts (thoughts may enter the individual’s internal speech loop or even become spoken aloud without the individual realising that the thoughts / speech are his own (malfunction of the feedback loop).

• Somatic e.g. experience of electric shocks to the fingertips.

Positive Symptoms

3) Delusions (beliefs which individuals are firmly convinced are true, regardless of evidence to the contrary). These can come in:-

• Delusions of grandeur: the individual is someone important or powerful (Christ, Napoleon).

• Delusions of persecution: the individual is being conspired against/interfered with by other people or organisations (M15, the Mafia).

• Delusions of reference: the individual believes that unrelated events have personal significance e.g. the words of a song refer to them personally.

• Other common delusions: the belief that nothing really exists and all things are simply shadows; the belief that one has been dead for years and it is observing the world from afar.

Negative SymptomsEmotional Disturbance• a) Blunting: apparent indifference to events which would normally

provoke a strong emotional reaction.• b) Inappropriate Affect: e.g. laughing when told bad news, reacting angrily

if offered a gift. • c) Flattened Affect: absence of emotional expression, speech is in

monotone, no mobility of facial features, vacant gaze.Lack of Volition • Loss of interest in the external and social world. Loss of drive. • Inability to act, including inability to perform everyday living activities e.g.

washing, cooking.Disordered Sense of Self • Sufferer has little idea who he / she is and has no ego-boundaries. The

sufferer displays autism, and lives in a fantasy world, taking no notice of the world around them.

Explanations – Biologicalvs Psychological

Nature vs Nurture

Diathesis Stress Model

• No-one believes Schizophrenia is completely caused by either genes or the environment.

• There must be an INTERACTION between the two.

• Diathesis = Genetic tendency to develop schizophrenia.

• Stress = Environmental “trigger” that starts it off.

Diathesis Stress Model

• Interesting Questions:• What is More important – nature or nurture?• How do we separate the effects of nature and

nurture? (People who share genes tend to share the same environment)

Biological Explanations

GeneticsBio chemicals

Brain Structure

Genetics – Twin Studies(AO1)

• Gottesman 1991 suggests that schizophrenia is inherited through genes.

• QUESTIONS: • Why study identical twins?• What would you expect to

find?

Genetics – Twin Studies(AO1)

• Rosenthal (1963) studied identical quadruplets who all developed schizophrenia.

• They differed in age of onset and symptoms.

• Genes or their terrible upbringing?

Genetics – Family Studies(AO1)

• Gottesman also concluded that if both your parents suffer from Schizophrenia, you have a 46% chance of developing it yourself (compared to a 1% chance of someone selected at random will suffer)

• The more genetically similar relatives are, the more concordance is found.

Schizophrenia: genetics

Source: Gottesman (1991)

www.

psyc

hlot

ron.

org.

uk

Genetics – Adoption Studies(AO1)

• WHY did Tienari et al (2000) study adopted people whose mothers had been diagnosed with schizophrenia?

• He found:• 6% born to schizophrenic mothers

developed schizophrenia while• 2% control adoptees born to non

schizophrenic mothers developed schizophrenia

• QUESTION: what does this suggest?

Evaluating Genetic Explanations(AO2)

• Make two evaluation points about:• Twin Studies• Family Studies• Adoption Studies

Biochemical Factors – The Dopamine Hypothesis• This theory claims that excessive

amounts of dopamine or an oversensitivity of the brain to dopamine is the cause of schizophrenia

• There are 3 pieces of evidence to support this:

• 1. Drugs which block dopamine (Phenothaiazines) reduce the symptoms of schizophrenia.

The Dopamine Hypothesis -

• 2. L-Dopa – a drug for Parkinson’s disease actually increases dopamine – this in turn can produce symptoms of schizophrenia.

• 3. Post mortems of schizophrenics, show an increase of dopamine in parts of the brain. (Seeman 1987)

Schizophrenia & dopamine

• The dopamine hypothesis:– Schizophrenia is caused by excessive DA activity. – This causes abnormal functioning of DA-

dependent brain systems, resulting in schizophrenic symptoms

– DA can increase or decrease brain activity depending on the system you’re looking at

psyc

hlot

ron.

org.

uk

The dopamine hypothesis

• Wise & Stein (1973) report abnormally low levels of DBH in post-mortem studies of S patients– Would suggest abnormally high DA activity as DBH

needed to break DA down– Can’t rule out cause of death or post-mortem

changes as a source or error

psyc

hlot

ron.

org.

uk

The dopamine hypothesis

• Overdose of amphetamine (DA agonist) can produce S-like symptoms. S patients have abnormally large responses to low amphetamine doses– Suggests a role for DA in S symptoms– Suggests that the issue is over-sensitivity to DA

rather than excessive DA levels

psyc

hlot

ron.

org.

uk

The dopamine hypothesis

• S symptoms can be treated with DA antagonists (e.g. chlorpromazine). These are effective in 60% of cases with more impact on positive symptoms.– Supports role of DA again, but what about 40%

who don’t respond?– Lack of impact on negative symptoms hints at two

separate syndromes

psyc

hlot

ron.

org.

uk

Evaluating the Dopamine Hypothesis(AO2)

• Write six evaluation points, examining the evidence on your handout.

•

Brain Structure

People with schizophrenia have abnormally large ventricles in the brain. Ventricles are fluid filled cavities. This means that the brains of schizophrenics are lighter than normal.

Brain Structure Evidence

• Andreasen et 1990 – conducted a controlled CAT scan study and found significant enlargement of the ventricles in schizophrenics compared to controls.

Biological explanations

• No one is sure if there are a range of different biological problems which together cause schizophrenia or if there are actually different types of schizophrenia which may have different causes.

Two Syndrome Hypothesis - Crow 1985 – there maybe two different types!

• Type one - genetically inherited associated with dopamine – characterised by positive symptoms.

• Type Two – Neurodevelopmental disorder – to do with Brain structure – characterised by negative symptoms.

Positive and Negative Symptoms

• Positive - hallucinations, delusions, racing thoughts (high)

• Negative - apathy, lack of emotion, poor social functioning, and cognitive disorganized etc. (low).

Advantages of the biological model

• 1. It is scientific • 2. It offers drug therapy • 3. It may offer a cure

Problems with biological model

• 1. There is conflicting biological evidence• 2. We cannot be sure that schizophrenia is one disorder • 3. We cannot prove cause and effect • 4. There are alternative explanations• 5. It is difficult to separate out genes from social

situations. • 6. Genetic inheritance it is only a predictor of a

‘predisposition’ and is not a predictor of actually getting the disorder.

• 7. Biological explanations are therefore incomplete

Psychological Explanations for schizophrenia - Behaviourism

• Behaviourists would look not only at how patients ‘learn’ to develop faulty behaviour patterns but also at how they learn faulty thinking!

Operant Conditioning & schizophrenia

• Children who do not receive reinforcement for ‘normal’ behaviour may put inappropriate attention into irrelevant environmental cues.

• For example: paying attention to the sound of a word rather than meaning.

• This behaviour will eventually appear ‘weird’ to others.

• These strange behaviours may be rewarded by attention and sympathy and so are reinforced.

• This can continue until the behaviour becomes labelled as schizophrenic. (Rosenhan)

Punishment and schizophrenia

• Another suggestion is that early experience of punishment may lead the child to retreat into a rewarding inner world. Others then label them as ‘odd’ or ‘strange’. (Think MPD and Eve White)

Social learning & schizophrenia

• Families affect social learning. • Bizarre behaviour by parents is copied by

children. • Parents then reinforce this behaviour, until

eventually the child acquires the label of being ‘schizophrenic’.

Evidence to support operant conditioning & reinforcement in schizophrenia

• Ullman (1969) observed mental health nurses in their interactions with patients and concluded that staff actually reinforce schizophrenic behaviour by giving more attention to these patients – thus increasing the likelihood of the behaviour reoccurring.

Evidence for Social learning and schizophrenia

• Roder et al. (2002) used social skills training techniques to help schizophrenics. The success of training programmes in teaching new skills and reintegrating schizophrenics back into the community suggests that these are social skills that schizophrenics failed to learn in the first place.

The Cognitive Model of Schizophrenia

• Beck explains the disorder is due to genetic, environmental, psychosocial and cognitive factors which all interact.

• The cognitive model of schizophrenia can, therefore, be considered a holistic approach to the disorder.

The Stress diathesis ModelCognitive

• Genetic abnormalities create a predisposition for the development of the disorder, but the disorder only develops in response to stress. The more stressors accumulate, the greater the risk a susceptible person has of developing schizophrenia.

• Stress affects the development of the hippocampus which in turn affects cognitive skills.

The Diathesis-Stress Model

• A person with a predisposition to develop schizophrenia has limited cognitive resources due to biological factors such as high dopamine, larger ventricles and poor hippocampus development. However, as long as life is relatively stress-free they are able to compensate for this and their behaviour appears normal.

Cognitive treatments for schizophrenia

• Bradshaw 1998 (Case Study)• Bradshaw used CBT in the long-term outpatient care

of a young woman with schizophrenia. Measures of psychosocial functioning, severity of symptoms, compliance with treatment and reductions in hospital visits were used to assess change over the 3- year treatment period and at 1-year follow-up. Results indicate considerable improvement in all outcomes.

Evaluation for psychological explanations for schizophrenia

• Behavioural explanations lack conviction. It is highly unlikely we can ‘learn’ schizophrenia!

• Behaviourist explanations may explain maintenance, or differences in ability to deal with the disorder, rather than being a cause of the disorder

• The cognitive explanation is however more holistic and complete (and therefore less reductionist) than either the biological or behaviourist model

Evaluation• Psychological models are very useful in

treatment programmes. Giving patients the cognitive skills to deal with their disorder can reduce the symptoms.

• Behavioural techniques can help patients fit into the community by improving social skills.

• Cognitive / behavioural therapies are less unethical, and have no side effects compared to drug therapy. They are however expensive.

Evaluation

• On the other hand, some patients are just too sick to responds to psychological therapy and are also too sick to self report about their experiences, making this area very difficult to investigate with any reliability or validity.

• Psychological explanations are unlikely to lead to a cure!