Schizophrenia Notes

What is schizophrenia?

It is a psychotic disorder characterised by severely impaired thinking, emotions, and behaviours.

What do patients with schizophrenia suffer with?

Filtering sensory stimuli, leading to enhanced perceptions.

What type of symptoms do patients suffer with?

• Positive

• Negative

What are positive symptoms?

Enhance the typical experience, occurring in addition to normal experiences.

What are examples of positive symptoms?

Hallucinations and delusions.

What are negative symptoms?

Represent a 'loss' of typical experiences.

What are types of negative symptoms?

Examples include speech poverty and avolition.

What are hallucinations?

Distorted perceptions of real stimuli or perceptions with no basis in reality

What is a type of hallucination?

Auditory

What are auditory hallucinations?

They may involve voices of loved ones or the deceased, caused by excess dopamine receptors in Broca’s area (a neural correlate).

What are delusions?

Beliefs with no basis in reality

What are types of delusions?

• Persecutory

• Delusions of grandeur

• Delusional jealousy

• Erotomania

• Somatic delusional disorders.

What is speech poverty?

Abnormally low frequency and quality of speech.

What are types of speech poverty?

A common type is 'derailment,' potentially caused by dysfunctions in central control (Frith et al, 1992), hindering the suppression of automatic associations.

What is avolition?

Reduction in interests, desires, and goals; behavioural reduction of self-initiated and purposeful acts.

What is the result of avolition?

Inability to cope with normal pressures and motivations.

What are classification systems for mental disorders?

• Diagnostic and Statistical Manual (DSM-V)

• International Classification of Diseases (ICD-10)

What is the DSM-V?

Requires at least two of the following: delusions, hallucinations, disorganised speech, and catatonic behaviour; persistence of symptoms for at least 1 month, more specific diagnostic criteria.

What is the ICD-10?

Broader approach, stating the clinical picture is dominated by stable, often paranoid delusions, accompanied by hallucinations; persistence of symptoms for at least 1 month.

What are the differences between DSM and the ICD?

• Originating organisations: WHO vs. American Psychiatric Association.

• Number and specificity of symptoms required for diagnosis.

• Recognition of different subtypes of schizophrenia.

What are subtypes of schizophrenia?

• Positive schizophrenia: Prominent delusions, hallucinations, and positive formal thought disorders.

• Mixed schizophrenia: Prominent symptoms are either both negative and positive, or neither is prominent.

• Subtypes are currently recognised in the ICD-10 only.

What is co-morbidity of schizophrenia?

Significant co-morbidity exists between schizophrenia and other mental health disorders like OCD and PTSD (Buckley et al, 2009).

What did Buckely et al (2009) find out about co-morbidity rates of schizophrenia?

He found that 29% of SZ patients suffered from post-traumatic stress disorder, whilst 50% suffered from depression

High co-morbidity with depression raises questions about the validity of differentiating SZ from other disorders.

What did Longenecker et al (2010) say about gender bias?

They noted a post-1980s increase in male SZ diagnoses without explanation.

What did Cotton et al (2009) say about gender bias?

They suggest that there are no differences in genetic susceptibility for men and women in terms of SZ, then gender bias must be to blame.

What is gender bias and validity?

• Dispositional traits in women may mask symptoms or distort their severity.

• Current diagnostic systems may not account for functional differences between men and women.

What did Escobar et al (2012) say about culture bias?

They suggest that African Americans are more likely to be diagnosed with SZ compared to Western cultures

What is culture bias and validity?

• Increased openness about admitting certain symptoms may appear normal in their cultures.

• Hearing voices may be seen as a sign of increased spirituality and connectedness with ancestors.

• Classification systems may misinterpret cultural phenomena as SZ characteristics.

What are biological explanations for schizophrenia?

• Candidate genes

• Dopamine hypothesis

• Neural correlates

What is the genetic basis for schizophrenia?

• Schizophrenia appears to run in families, suggesting a genetic basis.

• Gottesman (1991) demonstrated a positive correlation between genetic similarity and risk of developing schizophrenia.

• However, no 100% concordance rates indicate environmental influences.

What are the concordance rates for schizophrenia?

• Monozygotic twins (48%)

• Dizygotic twins (17%)

• Siblings (9%)

• Parents (6%)

What are candidate genes?

Ripke et al (2013) genome-wide study identified 22 loci at genome-wide significance, Researchers found “22 loci associated at genome-wide significance; 13 of these are new, and 1 was previously implicated in bipolar disorder”, alongside 8300 separate candidate genes.

• Each gene marginally increases the risk of developing SZ.

• Therefore, SZ is a polygenic disorder.

What is the original hypothesis?

Hyperdopaminergia (abnormally high dopamine levels) in the subcortex is responsible for SZ.

What is the revised hypothesis?

Hypodopaminergia (abnormally low dopamine levels) in the cortex is responsible for SZ.

What is the modern understanding of the dopamine hypothesis?

• Both hyper- and hypodopaminergia in different brain areas contribute to SZ.

• Hyperdopaminergia in the frontal lobe (Broca’s area) may cause auditory hallucinations.

• Goldman, Rakic et al (2004) suggested that hypodopaminergia in the prefrontal cortex causes negative symptoms like speech poverty and avolition.

• Prefrontal cortex: logical thinking; abnormally low dopamine levels; impaired ability to construct grammatical sentences or make decisions about day-to-day functioning.

• Implications for drug treatments: antipsychotics/dopamine antagonists.

What are neural correlates?

Specific patterns of cortical activity or neural structures that coincide with specific psychological symptoms.

What did Juckel et al (2006) say about neural correlates?

They suggested that abnormally low levels of activation in the ventral striatum may be associated with avolition.

• Ventral striatum = evaluating reward values, predictability and risks.

What did Allen et al (2007) say about neural correlates?

They found that misidentification of self-generated speech is associated with functional abnormalities in the anterior cingulate and left temporal cortex.

• SZ patients made more mistakes compared to the control group.

What evidence supports biological and genetic basis?

• Brown et al (2002) found that the risk of having offspring with SZ increased by over 1.3% if the father was over 50 years old, compared to if the father was under the age of 25.

• Mutations in DNA containing candidate genes (serotonin and dopamine production) suggest a strong heritability and biological basis.

What is the support for the dopamine hypothesis?

Tauscher et al (2014) found that antipsychotics alleviate symptoms.

What are the criticisms of the dopamine hypothesis?

Moghaddam and Javitt (2012) argue that glutamate and serotonin may also play a key role.

• Meltzer (2012) suggested that Clozapine acts upon both of these substances and is more effective than other atypical antipsychotics in reducing SZ symptoms

What are issues with neural correlates?

• Correlational evidence does not demonstrate causation.

• Third variable problem: An unstudied factor could be affecting both outcomes (lower activation levels and hallucinations). Could be the lowered activation levels causing the hallucinations, or the hallucinations themselves causing the lowered activation levels.

What are abnormal family communication styles?

• Schizophrenogenic mother

• Double-bind theory

• Expressed emotion

What is the schizophrenic mothers?

Fromm-Reichmann characterised the mother as cold and rejecting.

• Creates a tense family climate lacking honesty, leading to paranoia and anxiety that manifests as paranoid delusions.

What is the double bind theory according to Bateson?

The child receives mixed messages from parents about what is right or wrong.

• Tense atmosphere prevents clarification, and mistakes are punished with withdrawal of love, leading to confusion and disorganised thinking.

What is expressed emotion?

The level and type of emotion shown towards the patient by their carer.

• High levels lead to stress, reduced medication adherence, and increased relapse due to verbal criticism, needless sacrifices, and violence with hostility.

What are dysfunctional thought processes according to Frith et al (1992)?

• Metarepresentation

• Central control

What is Metarepresentation?

Cognitive ability to differentiate between our own actions and the actions of others, allowing us insight into the intentions and emotions as others, as well as maintaining a realistic/functional view of our own goals and intentions.

• Dysfunctions associated with auditory hallucinations and thought insertion because to the inability to differentiate between our own thoughts and those of others. This may lead to paranoid delusions due to the contents of inserting others’ thoughts into the mind of the patient.

What is central control?

Carrying out a deliberate action whilst suppressing an automatic response, often measured using the Stroop Test.

• People with SZ often have dysfunctional central control abilities, and so often suffer from derailment because they cannot suppress the automatic associations that each new word in a sentence brings, and so begin to talk off-topic.

What evidence supports dysfunctional thought processes?

• Stirling et al (2006) found that SZ sufferers made more mistakes and took longer to complete tasks, compared to a healthy neurotypical control group.

• Dysfunctional thought processing explains the indirect proximal causes but not the distal causes, which limits its utility.

What is the comparison between biological and psychological explanations?

• Psychological explanations do not accommodate biological factors.

  • Weakness as a biological factors can explain distal origins.

• Psychological explanations focus on proximal causes, which are more likely to be affected by psychological factors.

What is the lack of support for family-based explanations?

• The idea of the schizophrenogenic mother was based upon historical observations of families with SZ members, where observers would be searching for ‘crazy-making characteristics’, which is hardly an objective and reliable indicator of the likelihood of developing SZ.

• Places blame on families and caregivers, without genetic or biological predisposition.

  • Further hurt when they are forced to accept responsibility for their patient’s schizophrenia, which is likely to have already upset family life and relationships through the development of severe and intrusive negative and positive symptoms.

What types of antipsychotics are there?

• Typical

• Atypical

What are antipsychotics?

They are dopamine antagonists that bind to complementary dopamine receptors on the postsynaptic membrane, preventing dopamine molecules from binding.

What is the result of antipsychotics?

An inhibitory effect, where there is a lower rate of action potential generation in the postsynaptic membranes, and so returns neurotransmission (e.g. in the prefrontal cortex and subcortices) to a normal level.

What are typical antipsychotics?

Favoured for calming and sedative effects, acting upon histamine receptors in addition to dopamine receptors (particularly favoured in psychiatric institutions).

What are examples of typical antipsychotics?

First-generation drugs, such as Chlorpromazine.

What are atypical antipsychotics?

Second-generation drugs, developed to add to the effectiveness of first-generation medications, and also alleviate the serious side effects

What are examples atypical antipsychotics?

• Clozapine

• Risperidone

What is Clozapine?

Targets serotonin and glutamate receptors.

What is Risperidone?

Acts on dopamine and serotonin receptors

What are key advantages of clozepine?

Improvements in cognitive functioning and mood.

What are key advantages of Risperidone?

Smaller doses are required because it acts more strongly on dopamine receptors compared to Clozapine

What is the development of antipsychotics based on the dopamine hypothesis?

Paradox: appears to alleviate symptoms by reducing the action of dopamine. This action is not in line with the revised version of the dopamine hypothesis, which suggests that abnormally low levels of dopamine in the cortex are responsible for symptoms. Therefore, a further reduction in dopamine levels should make symptoms worse, and not better. This paradox has caused some to question the validity of the use of antipsychotics, as well as the accuracy of the dopamine hypothesis as an explanation for schizophrenia.

What are short-term effects of typical antipsychotics?

Agitation and weight gain

What are long term risks of typical antipsychotics?

Tardive dyskinesia (characterised by involuntary contraction and relaxation of the facial muscles) and neuroleptic malignant syndrome (NMS; characterised by fever, altered mental states, muscle rigidity and autonomic dysfunction and is thought to be caused by dopamine receptor blockage or central nervous system infections).

What are atypical side effects?

Agranulocytosis (severe leukopenia) with Clozapine, requiring continuous monitoring.

What are the main psychological therapies for schizophrenia?

• Cognitive Behaviour Therapy (CBT)

• Family Therapy

• Token Economy Systems

What is cognitive behaviour therapy (CBT)?

• Initial assessment to clarify symptoms and problems.

• Emphasises understanding the causes of symptoms, which reduces the intrusive effects of their symptoms and increases their self-awareness, reassures patients that they are not ‘crazy’.

• Effective behaviours are put into place by questioning the reality of the patient’s beliefs and considering other, more reasonable alternatives.

What is family therapy?

• Aims to reduce stress by improving families’ beliefs and attitudes towards schizophrenia.

• Reduces stress, increases self-efficacy, and trains families to look for signs preceding an episode.

What are token economies?

• Based upon behaviourist principles

• Target, desirable behaviours are identified.

• Patients are rewarded with a token (secondary reinforcer) exchanged for a reward or privilege (primary reinforcer). Therefore, patients are motivated by the primary reinforcer to carry out the desirable behaviours, and their frequency of doing so increases as they are positively reinforced.

• Rewards may include extra TV time, exercise taken outside of the grounds of the hospitals and favourite magazines.

What are limitations of psychological therapies?

Simply improve their quality of life by making the symptoms more manageable. For example, token economies increase the likelihood that the patients act in accordance with hospital rules and break disruptive patterns of behaviour, whilst family therapies reduce stress within a schizophrenic family and so increase the likelihood of the patient complying with their medical advice, whereas CBT improves the patient’s understanding of their symptoms.

What are ethical issues of psychological therapies?

Ethical issues associated with the use of psychological therapies, and specifically concerning token economies.

How can you integrate biological and psychological explanations and therapies?

Central to the idea of an interactionist approach is the use of the diathesis-stress model

What are the features of Meehl’s (1962) outdated model?

• Diathesis

• Stressor

What does diathesis mean according to the outdated mode?

Biological in origin (i.e. a single ‘schizogene’) which causes a schizotypic personality which in turn eventually manifests itself as schizophrenia.

What does stressor mean according to the outdated mode?

Purely psychological stressor (excessive exposure to stress, particularly through the schizophrenogenic mother)

What is the modern understanding of stress?

Not biological in origin but could also be psychological, such as in the form of childhood trauma, as suggested by Ingram and Luxton (2005).

What is the modern understanding of diathesis?

Not limited to psychological factors but could also be biological in nature, as long as it increases the risk of developing SZ, as according to Houston et al (2008).

What is evidence of the interactionist approach to schizophrenia?

Tienari et al's 2004 adoption study: Found family ratings were a significant predictor of schizophrenia spectrum disorders.

What is the therapeutic advantage to the interactionist approach to schizophrenia?

Tarrier et al (2004): Tarrier et al (2004). The researchers studied 315 patients who were randomly allocated to one of three conditions, where the last control group received no treatment and the first two groups received a combination of psychological and biological treatments. The researchers found that, after an 18-month follow-up, “there were significant advantages for CBT and supportive counselling over TAU (treatment as usual) alone on symptom measures at 18 months, but no group difference was seen for relapse or re-hospitalisation.