Schizophrenia

Schizophrenia Definition

A serious mental disorder that affects how a person thinks, feels and behaves. It can cause difficulties distinguishing what is real

Diagnosis of Schizophrenia

• Male onset for schizophrenia is in late teens, females is early twenties

• Around 0.3% of the population experience schizophrenia

• Schizophrenia is diagnosed using axes DSM V and ICD 11

Symptoms of Schizophrenia

• Positive symptoms - addition to normal functioning

• Negative symptoms - reduction in normal functioning

Positive Symptoms of Schizophrenia

• Hallucinations - unusual sensory experiences, such as auditory, visual, tactile, olfactory

• Delusions - false cognitive beliefs, such as grandeur and persecution

Negative Symptoms of Schizophrenia

• Speech poverty - reduction in amount and quality of speech

• Avolition - apathy, finding it hard to keep up with goal oriented activities

Issues in Diagnosis Definition

Diagnosing schizophrenia is not always straightforward

Issues in Diagnosis

• Symptom overlap

• Co-morbidity

• Gender bias

• Culture bias

Symptom Overlap

• When symptoms shown are also shown in other disorders, so diagnosis is inaccurate

• Auditory hallucinations overlap with bipolar

Symptom Overlap Evaluation

Supporting evidence - 14 autistic patients and 14 schizophrenic patients, 7 autistic were also found to show the same symptoms

Co-Morbidity

• When two or more mental health disorders are present at once, meaning both symptoms are present and can not be used for a valid diagnosis

• Depression appears alongside schizophrenia, treatment may only target one, leading to worsening of symptoms

Co-Morbidity Evaluation

Supporting evidence - 50% of schizophrenics also experience depression

Gender Bias

• When the accuracy of diagnosis is dependent of gender of person examined

• Men diagnosed more than women, scale 1.41 to 1

Gender Bias Evaluation

Supporting evidence - women show better interpersonal skills and weaker symptoms so may be overlooked

Found that 56% were diagnosed when gendered male, but 20% when described as female, but this bias did not exist when the clinican was female

Cultural Bias

• When reliability of diagnosis is reduced to psychiatrists misinterpreting symptoms from other cultures

• African - Caribbean descent found more likely to be diagnosed due to beliefs being mistaken for psychosis

Cultural Bias Evaluation

Supporting evidence - 9x more likely to recieve diagnosis than white patients, but were not diagnosed as such in non-western countries

Biological Explanations of Schizopnrenia

• Genetic basis

• Neural correlates

Genetic Basis of Schizophrenia

• Candidate genes

• Family studies

Neural Correlates for Schizophrenia

• Dopamine hypothesis

• Grey matter/ventricles

Candidate Genes

• Schizophrenia is hereditary - passed on through genes

• Gene mapping shows there is not a single ‘schizophrenic gene’, but 108 involved in increasing vulnerability (polygenic), such as PCM1 and NRG3

Family Studies

• Risk of schizophrenia increases with genetic similarity to a relative who also has schizophrenia

• Gottesman found 48% concordance rate for MZ twins, 17% for DZ

• More genetically similar you are, more likely you are to also develop the disorder

• Tienari et al studied 164 adoptees whose biological mothers had schizophrenia, found 11 (6.7%) of them developed the disorder compared to 4 (2%) of a control group

Genetic Basis Strengths

Supporting research evidence - Tienari et al shows support for the influence of genes on developing schizophrenia in different enviornments + Gottesman found not 100% concordance, so enviornment must play a role

Biological Explanations Limitations

Biologically reductionist - ignores other factors of developing schizophrenia, Morkved et al found 67% report childhood trauma event compared to 38% of non psychotic patient

Dopamine Hypothesis

• Original dopamine hypothesis

• Recent dopamine hypothesis

Original Dopamine Hypothesis

• Excess dopamine levels in the subcortical areas of the brain cause positive symptoms

• Hyperdopamainergia

• Excess in Broca’s area linked to auditory hallucinations

Recent Dopamine Hypothesis

• Low levels of dopamine in the cerebral cortex cause negative symptoms

• Hypodopamainergia

• Low in pre frontal cortex linked to avolition

Grey Matter/Ventricles

• Enlarged ventricles is linked to development of SZ

• Suggested to be a result of lost grey matter which also leads to reduced function in the prefrontal cortex

• Schizophrenics have 20% larger ventricles

Dopamine Hypothesis Strengths

Supporting research evidence - Curren found non SZ patients taking amphetamines (increasing dopamine) led to positive symptoms

Dopamine Hypothesis Weaknesses

Contradicting research evidence - Noll found anti-psychotics (reduce dopamine) only relieve negative symptoms in 2/3 of people

Ventricles Strengths

Practical Applications - Neuroimaging used to identify enlarged ventricles as a preventative method

Anti-Psychotic Drugs

Aim to reunite a person with reality

Types of Anti Psychotic Drugs

• Typical

• Atypical

Typical Anti Psychotics (Chlorpromazine)

• First generation drugs, work off the original dopamine hypothesis

• Dopamine antagonist - bind to D2 receptors to prevent too much dopamine being absorbed

• Reduces positive symptoms of schizophrenia

Atypical Anti Psychotics (Clozapine)

• Binds to dopamine, serotonin and glutamate receptors

• Treats positive and negative symptoms of schizophrenia - reduce depression and anxiety so more useful for comorbidity patients

• Withdrawn following the deaths of some patients fron agranulocytosis - severe decrease in white blood cells, leading to infection and death

Biological Treatments Strengths

• Supporting research evidence - Thornley et al reviewed data from 13 trials (1121 patients) and found that chlorpromazine was associated with better functioning and reduced symptom severity compared to a placebo + Noll found 1/3 of people do not have reduced symptoms

Biological Treatments Weaknesses

• Side effects - long term use can lead to tardive dyskensia (involuntary movement)

• Do not address root cause - anti psychotics reduce dopamine levels in the brain, masking the symptoms, meaning they may come back + drug treatments are more time and cost effective + best treatment is a combination

Psychological Explanations

• Family Dysfunction

• Cognitive

Family Dysfunction

• Schizophrenogenic mothers

• Double bind

• Expressed emotion

Schizophrenogenic Mothers

• Frieda Fromm-Reichmann - schizophrenia causing mothers

• Characterised by being cold, rejecting and controlling

• Create family climate characterised by tension and secrecy

• Leads to distrust, developing into persecutory delusions

Double Bind

• Bateson - role of communication style

• Children who frequently recieve contradictory messages are more likely to develop schizophrenia

• Fear doing the wrong thing but recieve mixed signals on what this is

• Confused understanding of the world, leading to disorganised thinking

Expressed Emotion

• Negative emotional climate causes schizophrenia

• Expressed emotion is a family communication style involving criticism, hostility and emotional overinvolvement

• Unlikely high emotion leads to onset, but may instead increase the chance of relapse

Family Dysfunction Strengths

• Supporting research evidence - Read et al reviewed 46 studies and concluded 69% of sz women and 59% of sz men had a history of physical/sexual abuse + does rely on memory which may be distorted due to sz

Family Dysfunction Weaknesses

• Explanations lack support - very little evidence to support, based only clinical observations which are subjective, lack credibility and are hard to establish cause and effect

• Ethical implications - places the blame on parents which adds trauma when they are already coping with care of child + led to development of family therapies which shows real world application