Source: Abnormal Psychology, University of Florida
Tags: schizophrenia, psychosis, delusions, hallucinations, positive symptoms, negative symptoms, dopamine hypothesis, antipsychotics, neuroleptics, schizoaffective, schizophreniform, catatonia, avolition, restricted affect
Difficulty: Intermediate-Advanced | Prerequisites: Basic neuroscience concepts (neurotransmitters, brain structures), understanding of genetic research methods (twin studies, concordance rates)
Schizophrenia is among the most severe and debilitating of all mental disorders. It is characterised by psychosis, the inability to distinguish real from unreal, and it affects virtually every domain of functioning: thinking, perception, emotion, motivation, and social behaviour. The disorder exists on a spectrum of severity, with related conditions (schizoaffective, schizophreniform, brief psychotic disorder, delusional disorder) falling along a continuum. Understanding schizophrenia requires integrating biological theories (genetics, brain structure, neurotransmitters) with psychosocial perspectives (stress, family dynamics, culture). Treatment has advanced substantially since the 1950s with antipsychotic medication, but full recovery remains uncommon and long-term management is usually necessary.
Schizophrenia involves psychotic symptoms (delusions, hallucinations, disorganised thought/behaviour) and negative symptoms (restricted affect, avolition). It is a neurodevelopmental disorder with strong genetic contributions, abnormal brain structure and neurotransmitter function (especially dopamine), and psychosocial triggers. Antipsychotic medications manage positive symptoms but are less effective for negative symptoms. Comprehensive treatment combines medication with behavioural, cognitive, social, and family interventions.
Psychosis
Inability to distinguish between what is real and what is not. Can take many forms including delusions, hallucinations, and disorganised thinking.
Positive Symptoms
Overt expressions of unusual perceptions, thoughts, and behaviours that are "added" to normal experience: delusions, hallucinations, disorganised thought and speech, disorganised or catatonic behaviour.
Negative Symptoms
Qualities that are "subtracted" from normal functioning: restricted affect, avolition, asociality. More persistent, harder to treat, and more strongly associated with poor outcomes than positive symptoms.
Delusions
Fixed beliefs that are not amenable to change in light of conflicting evidence. DSM-5 changed the definition from "erroneous beliefs" to acknowledge the difficulty of establishing full falsity of a belief.
Think of it as: beliefs the person holds with absolute conviction despite overwhelming evidence to the contrary.
Hallucinations
Unreal perceptual experiences. Can involve any sense, but auditory hallucinations (hearing voices) are the most common in schizophrenia.
Formal Thought Disorder
The disorganised thinking characteristic of schizophrenia, evident in speech.
Loose Associations (Derailment)
Slipping from one topic to an unrelated topic with no coherent transition.
Neologisms
Made-up words that have meaning only to the person using them.
Clangs
Word associations based on sound rather than meaning.
Word Salad
Speech so disorganised that it is completely incoherent.
Catatonia
Disorganised behaviour reflecting unresponsiveness to the environment. Ranges from negativism (refusing instructions) to rigid or bizarre posturing to complete mutism.
Catatonic Excitement
Purposeless, excessive motor activity for no apparent reason.
Restricted Affect
Severe reduction or absence of emotional expression: fewer facial expressions, reduced eye contact, flat voice, limited use of gestures.
Anhedonia
Loss of ability to experience pleasure. People with schizophrenia self-report anhedonia but laboratory tests show normal levels of positive affect, suggesting possible limitations of self-report or secondary depression.
Avolition
Inability to initiate or persist at common, goal-directed activities. May include physical slowing, apparent lack of motivation, poor hygiene, and social withdrawal.
Asociality
Lack of desire to interact with others. Should only be diagnosed when the individual has access to welcoming relationships but shows no interest.
Prodromal Symptoms
Symptoms appearing before the acute phase: social withdrawal, unusual beliefs short of delusions, strange perceptual experiences short of hallucinations, mildly disorganised speech.
Residual Symptoms
Symptoms persisting after the acute phase, similar to prodromal symptoms.
Dementia Praecox
Emil Kraepelin's original label for schizophrenia, reflecting his belief that the disorder was a progressive, irreversible deterioration of the brain.
Expressed Emotion
A family environment characterised by overinvolvement, overprotectiveness, self-sacrificing attitudes, and simultaneous criticism, hostility, and resentment toward the family member with schizophrenia. Associated with higher relapse rates.
Persecutory: belief that one is being watched, tormented, or conspired against
Delusion of reference: belief that random events or others' comments are directed at oneself
Grandiose: belief that one is a special being or possesses special powers
Thought insertion: belief that one's thoughts are being controlled by outside forces
Auditory: hearing voices (most common)
Visual: seeing things, usually accompanied by auditory hallucinations
Tactile: perception that something is happening on the surface of the body
Somatic: perception that something is happening inside the body
Deficits in attention, memory, and processing speed
Greater difficulty focusing and maintaining attention
Deficits in working memory (holding and manipulating information)
Difficulty distinguishing relevant from irrelevant information
These deficits may contribute to the development of hallucinations and delusions as the person struggles to make sense of overwhelming input
Relatives may show milder versions of these deficits even without schizophrenia symptoms
Cognitive deficits often appear before acute symptoms and do not improve with treatment
Strongly contribute to overall disability
Must show two or more psychotic symptoms, at least one of which must be delusions, hallucinations, or disorganised speech
Symptoms must be consistently and acutely present for at least one month
Must show symptoms for at least six months with impaired functioning
Symptoms cannot be attributed to substance use, medical condition, or a mood disorder
Catatonia, when present, is specified in the diagnosis
During the six months before and after the active phase, the person may show mostly negative symptoms with milder positive symptoms
DSM-5 removed earlier subtypes (e.g. paranoid schizophrenia)
Usually chronic, with symptoms and impairments lasting many years even with treatment
Shorter life expectancy; higher rates of infectious and circulatory diseases
Stabilisation typically occurs within 5 to 10 years after onset
Women tend to have better prognosis: less hospitalisation, milder inter-episode symptoms, better social adjustment, better educational and occupational histories
Women's later onset (late twenties to early thirties vs. late teens to early twenties for men) may partly explain the gender difference
Oestrogen may affect dopamine regulation and be protective for women
Males show greater brain abnormalities than females with schizophrenia
More benign course in developing countries, possibly due to broader family support networks, lower expressed emotion, and greater community reintegration
Social drift: symptoms interfere with education and employment, causing downward movement in social class
Schizoaffective disorder: mix of schizophrenia and a mood disorder. Psychotic and mood symptoms co-occur. Requires two weeks of hallucinations or delusions without mood symptoms.
Schizophreniform disorder: meets schizophrenia criteria A, D, and E but symptoms last only 1 to 6 months. Majority eventually diagnosed with schizophrenia or schizoaffective disorder.
Brief psychotic disorder: sudden onset, lasts 1 day to 1 month, then symptoms completely resolve. High relapse risk but excellent long-term outcome.
Delusional disorder: delusions lasting at least one month about realistic situations, with no other psychotic symptoms. Affects females more; onset typically around age 40 to 49.
Schizotypal personality disorder: lifelong pattern of oddities in self-concept, relationships, thinking, and behaviour. Milder cognitive deficits, dopamine dysregulation, and brain abnormalities compared to schizophrenia. Falls on the schizophrenia spectrum and is also classified as a personality disorder.
Genetics
Family, twin, and adoption studies demonstrate a genetic component
Children of parents with schizophrenia and monozygotic twins have the highest risk
Concordance: MZ twins ~46%, DZ twins ~14%
Finnish study: 83% of variance in schizophrenia attributable to genetic factors
Adoption studies (Tienari, Kety) confirm genetic transmission
No single gene accounts for schizophrenia; many gene differences are implicated
Brain Structure and Function
Viewed as a neurodevelopmental disorder
Gross reduction in grey matter in cortex (medial temporal, superior temporal, prefrontal areas)
Abnormal prefrontal cortex activity (involved in language, emotional expression, planning)
Hippocampus abnormalities in volume and shape; similar abnormalities in first-degree relatives
Reduced and abnormal white matter, especially in areas related to working memory; present before overt symptoms
Enlarged ventricles suggesting brain tissue atrophy
Adolescent brain development abnormalities may trigger the disorder
Damage to Developing Brain
Serious prenatal and birth complications are frequent
Perinatal hypoxia interacts with genetic vulnerability
Prenatal viral exposure, especially during the second trimester, disrupts brain development; people with schizophrenia are more likely to be born in spring (mothers exposed to flu in autumn/winter)
Maternal immune activation may damage fetal brain cells and dopamine systems
Neurotransmitters
Original dopamine hypothesis: excess dopamine in the brain causes schizophrenia symptoms. Supported by the fact that drugs blocking dopamine (phenothiazines) reduce positive symptoms, and drugs increasing dopamine (amphetamines) worsen them.
Revised dopamine hypothesis: excessive dopamine in the mesolimbic pathway (processing salience and reward) produces positive symptoms and motivational deficits. Low dopamine in the prefrontal cortex produces negative symptoms. This explains why traditional antipsychotics reduce positive but not negative symptoms.
Serotonin neurons regulate dopamine in the mesolimbic system; newer drugs bind to serotonin receptors
Abnormal GABA levels implicated
Glutamate pathways link cortex, limbic system, and thalamus; drugs blocking glutamate receptors (PCP, ketamine) produce hallucinations and delusions
Stressful circumstances can trigger new episodes; negative life events may themselves be prodromal symptoms
Immigration is associated with increased risk
Early theories blamed "schizophrenogenic mothers" (overprotective, rejecting, dominating) and double-bind communication, but these did not hold up to research
Expressed emotion in families (overinvolvement + hostility + criticism) is associated with higher relapse rates; interventions that reduce expressed emotion reduce relapse
Family members high in expressed emotion often have psychological disorders themselves; genetic factors shared with the patient may partly explain the association
People with schizophrenia conserve limited cognitive resources by using biased thinking styles
Delusions arise as explanations for strange perceptual experiences
Hallucinations result from hypersensitivity to perceptual input combined with external attribution
Negative symptoms arise from expectations that social interactions will be aversive
Cognitive therapies help patients identify and challenge delusional beliefs and hallucinatory experiences
Typical Antipsychotics (Neuroleptics)
Chlorpromazine (first effective drug, 1950s) and others (trifluoperazine, thioridazine, fluphenazine, perphenazine)
Block dopamine receptors, reducing positive symptoms
Side effects: grogginess, dry mouth, blurred vision, weight changes, sexual dysfunction, depression
Akinesia (slowed motor activity, monotone speech, expressionless face)
Parkinsonian side effects: muscle stiffness, tremors, spasms, akathisia (inability to sit still)
Tardive dyskinesia: involuntary movements of tongue, face, mouth, or jaw. Irreversible. Occurs in 20% with long-term use.
More effective for positive than negative symptoms
Patients must continue medication to prevent relapse
Atypical Antipsychotics
More effective with fewer neurological side effects
Clozapine: binds to D4 receptor, influences serotonin. Helps patients who did not respond to neuroleptics. Reduces both positive and negative symptoms. Does not cause tardive dyskinesia. Risk of agranulocytosis (potentially fatal bone marrow deficiency), so used only after other atypical antipsychotics fail.
Others: risperidone (Risperdal), olanzapine (Zyprexa), ziprasidone (Geodon). No agranulocytosis risk, but significant side effects including weight gain, diabetes risk, sedation, sexual dysfunction.
Six-month remission rates: olanzapine highest, then quetiapine, perphenazine, ziprasidone, risperidone.
Psychological and Social Treatments
Cognitive treatments: help patients recognise and change demoralising attitudes, dispute delusional beliefs, develop realistic expectations about social interaction
Behavioural therapies: operant conditioning and modelling to teach conversational skills, self-care, and daily routines. Family members taught to ignore psychotic behaviour and reinforce appropriate behaviour.
Social interventions: self-help groups, social skills training, role-playing, problem-solving
Family therapy: education about schizophrenia, communication and problem-solving training, behavioural techniques for encouraging positive behaviour. Combined with medication, reduces relapse and improves adherence.
Assertive community treatment (ACT): comprehensive 24-hour services from multidisciplinary teams. Gold standard for community-based treatment. Includes the "lodge" model (residential treatment) and vocational rehabilitation. Reduces hospitalisation and is cost-effective, but chronically underfunded.
"Schizophrenia means split personality." Schizophrenia involves a split in mental functions (thought, emotion, perception), not multiple personalities. DID is the disorder involving distinct identities.
"Positive symptoms are 'good' symptoms." "Positive" refers to the presence of abnormal experiences (delusions, hallucinations), not to anything beneficial.
"If medication controls the symptoms, the person is cured." Medication manages symptoms, particularly positive ones, but negative symptoms and cognitive deficits often persist. Lifelong treatment is typically needed.
"Schizophrenia is caused by bad parenting." The "schizophrenogenic mother" theory has been thoroughly discredited. Schizophrenia has strong biological and genetic roots, though family environment can influence relapse.
⚠️ Know the five domains: positive symptoms, negative symptoms, and cognitive deficits. Be able to list examples of each.
⚠️ The original vs. revised dopamine hypothesis is high-yield exam material.
⚠️ Tardive dyskinesia: what it is, its cause, and its irreversibility.
⚠️ Know the differences between typical and atypical antipsychotics, including clozapine's unique risk (agranulocytosis).
⚠️ Be able to distinguish schizophrenia from schizoaffective, schizophreniform, brief psychotic disorder, and delusional disorder.
⚠️ Expressed emotion: definition and its relationship to relapse.
⚠️ Prodromal and residual symptoms: know what they look like and when they occur relative to the acute phase.
True or False: Negative symptoms of schizophrenia are more responsive to medication than positive symptoms.
Fill in the blank: __________ is a neurological side effect of long-term phenothiazine use involving involuntary facial and mouth movements.
True or False: The concordance rate for schizophrenia in monozygotic twins is approximately 46%.
Fill in the blank: Kraepelin originally labelled schizophrenia __________, believing it was a progressive and irreversible brain deterioration.
True or False: Brief psychotic disorder can last up to six months.
Q: What is the revised dopamine hypothesis of schizophrenia?
A: Excessive dopamine activity in the mesolimbic pathway produces positive symptoms (hallucinations, delusions, motivational deficits), while low dopamine activity in the prefrontal cortex produces negative symptoms. This explains why traditional antipsychotics (which broadly reduce dopamine) help positive but not negative symptoms.
Q: How does schizoaffective disorder differ from schizophrenia?
A: Schizoaffective disorder involves a combination of psychotic symptoms and prominent mood symptoms (meeting criteria for major depressive or manic episode). It requires at least two weeks of hallucinations or delusions without mood symptoms to distinguish it from a mood disorder with psychotic features.
Q: What is expressed emotion, and how does it relate to schizophrenia outcomes?
A: Expressed emotion describes a family environment characterised by overinvolvement, overprotectiveness, self-sacrificing attitudes, and simultaneous criticism, hostility, and resentment. High expressed emotion is associated with higher relapse rates. Interventions that reduce expressed emotion in families have been shown to reduce relapse.
Q: Why is clozapine not used as a first-line treatment?
A: Clozapine carries a risk of agranulocytosis (a potentially fatal deficiency of infection-fighting granulocytes produced by bone marrow). It is reserved for patients who have not responded to other atypical antipsychotics, and patients must be closely monitored.
Q: What evidence supports the neurodevelopmental model of schizophrenia?
A: Prenatal and birth complications, perinatal hypoxia, prenatal viral exposure (especially during the second trimester), grey matter reductions, white matter abnormalities, hippocampal abnormalities, and enlarged ventricles all point to disrupted brain development. Many of these abnormalities are present before symptom onset.
Schizophrenia connects to the neuroscience of dopamine (relevant to ADHD and substance use disorders as well), mood disorders (through schizoaffective disorder), and personality disorders (schizotypal personality disorder falls on the schizophrenia spectrum). The concept of expressed emotion links to family systems theory. The dopamine hypothesis connects to the pharmacology of stimulant drugs and Parkinson's disease.
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