L13 Psychological Medicine Introduction to psychotic spectrum disorders

Overview

This lecture introduces Psychosis and the Schizophrenia Spectrum and Other Psychotic Disorders category of the DSM-5-TR. It covers the definition and key features of psychosis, the DSM-5-TR diagnostic criteria and specifiers for schizophrenia, the eight disorders on the psychotic spectrum with their distinguishing features, the prevalence and social/economic cost of schizophrenia in Aotearoa New Zealand, how psychosis is assessed and screened for, and the broad categories of treatment and management.

What is psychosis?

The American Psychological Association defines psychosis as an abnormal mental state involving significant problems with reality testing, characterised by serious impairments or disruptions in the most fundamental higher brain functions (perception, cognition and cognitive processing, and emotions/affect), manifested behaviourally as delusions, hallucinations, and significantly disorganised speech.

The five key features that define psychosis:

• Delusions
• Hallucinations
• Disorganized thinking (speech)
• Grossly disorganized or abnormal motor behaviour (including catatonia)
• Negative symptoms

[slide does not elaborate individual definitions of delusions or hallucinations beyond naming them as key features; a “Delusions” explainer graphic was referenced but its caption text was illegible]

DSM-5-TR classification: Schizophrenia Spectrum and Other Psychotic Disorders

Eight disorders sit under this DSM-5-TR category:

• Schizotypal PD
• Delusional Disorder — subtypes: erotomanic, grandiose, jealous, persecutory, somatic
• Brief Psychotic Disorder — subtypes: with marked stressor, without marked stressor, postpartum
• Schizophreniform Disorder
• Schizophrenia
• Schizoaffective Disorder
• Substance induced (psychotic disorder)
• Catatonia — subtypes: with another disorder, medical condition, unspecified

DSM-5-TR diagnostic criteria for Schizophrenia

Criterion A — two (or more) of the following, each present for a significant portion of a 1-month period (or less if successfully treated), with at least one being (1), (2), or (3):

1. Delusions
2. Hallucinations
3. Disorganized speech (e.g. frequent derailment or incoherence)
4. Grossly disorganized or catatonic behaviour
5. Negative symptoms (diminished emotional expression or avolition)

Criterion B — since onset, functioning in one or more major areas (work, interpersonal relations, self-care) is markedly below the level achieved before onset, or (if onset in childhood/adolescence) there is failure to reach the expected level of interpersonal, academic, or occupational functioning.

Criterion C — continuous signs persist for at least 6 months, including at least 1 month of active-phase (Criterion A) symptoms; may include prodromal or residual periods with only negative symptoms, or attenuated positive symptoms (e.g. odd beliefs, unusual perceptual experiences).

Criterion D — schizoaffective disorder and depressive/bipolar disorder with psychotic features are ruled out, because either no major mood episodes occurred concurrently with active-phase symptoms, or mood episodes were present for only a minority of the total illness duration.

Criterion E — the disturbance is not attributable to the physiological effects of a substance or another medical condition.

Criterion F — with a history of autism spectrum disorder or a childhood-onset communication disorder, schizophrenia is additionally diagnosed only if prominent delusions or hallucinations, plus the other required symptoms, are present for at least 1 month (or less if successfully treated).

Course specifiers (used only after 1 year of illness, where consistent with the course criteria):

• First episode, currently in acute episode
• First episode, currently in partial remission
• First episode, currently in full remission
• Multiple episodes, currently in acute episode
• Multiple episodes, currently in partial remission
• Multiple episodes, currently in full remission
• Continuous
• Unspecified

Other specifiers:

• With catatonia (coding note: additional code 293.89/F06.1 for catatonia associated with schizophrenia)
• Current severity: each of delusions, hallucinations, disorganized speech, abnormal psychomotor behaviour, and negative symptoms is rated on a 5-point scale (0 = not present, 4 = present and severe) based on the most severe presentation in the last 7 days; the diagnosis of schizophrenia can be made without using this severity specifier.

Symptom clusters of Schizophrenia

• Reality distortion: delusions; hallucinations
• Psychomotor poverty: lack of effective responsiveness; loss of drive or volition; poverty of speech and movement
• Disorganisation: inappropriate affect; incoherent speech; disorganised behaviour
• Cognitive domain (impaired): attention and concentration; memory and learning; executive functioning (including abstract thinking and problem-solving)

Differential diagnosis of Schizophrenia

Before diagnosing schizophrenia, rule out:

• Delirium
• Dementia (especially in older patients)
• Depression
• Side effects of medication (e.g. heavy sedation)
• Learning disability
• Intoxication or withdrawal from psychoactive substances
• Psychosis due to a general medical condition (e.g. cerebral infections, HIV/AIDS, neurosyphilis, brain trauma, other neurodegenerative disorders)
• Psychoactive substance-induced psychotic disorder
• Culture-specific presentations/disorders
• Other mental disorders: delusional disorder, schizoaffective disorder, bipolar disorder, depressive disorder with psychotic features, schizophreniform disorder, brief psychotic disorder

Culture-specific presentations must always be considered, especially in Aotearoa New Zealand — bpacnz's "Māori Mental Health" resource is given as further reading on this point.

Prevalence, impact and cost of Schizophrenia in Aotearoa NZ

Based on a national cohort study (Gibb, Brewer & Bowden, NZMJ 2021) using linked administrative data. [flag: source abstract text was rendered small in the slide image; figures transcribed to the best of legibility]

Prevalence (2015): 18,096 people living with schizophrenia in NZ overall, 6.7 per 1,000.

• Sex: male 11,577 (8.9/1,000, reference group); female 6,519 (4.7/1,000)
• Ethnicity: European 11,730 (6.3/1,000); Māori 6,624 (16.7/1,000); Pacific 2,106 (10.9/1,000); Asian 1,065 (3.0/1,000)
• Age: 18–24: 1,068 (2.5/1,000); 25–34 (reference): 3,582 (6.5/1,000); 35–44: 4,854 (8.9/1,000); 45–54: 5,169 (8.2/1,000); 55–64: 3,423 (6.3/1,000)

Outcomes, schizophrenia population (N=15,639) vs matched non-schizophrenia population (N=15,639):

• Health: non-mental-health inpatient stay 13.0% vs 11.2% (OR 1.18 for physical health hospitalisation); mental health inpatient stay 12.2% vs 0.3% (OR 52.80); ED visit 6.7% vs 3.0%; ACC compensation 16.3% vs 29.8%
• Social support: any welfare benefit 78.8% vs 17.4% (OR 17.64); social housing 13.2% vs 4.3%
• Justice: police proceedings 9.4% vs 4.6%; conviction 4.7% vs 2.7%; prison sentence 2.3% vs 0.9%
• Economic: employed 27.6% vs 78.2% (OR 0.11); any income 91.0% vs 80.7%; mean income $17,865vs$44,092 (a difference of $26,226 lower); mean NZDep13 decile 7.4 vs 5.9 (greater deprivation)

Per-person government costs: health $17,333vs$2,486; social support $14,667vs$2,845; justice sector $795vs$431; total government cost $32,795vs$5,762.

Summary of the Psychotic Spectrum Disorders

Disorder	Key symptoms	Worldwide prevalence	Age of onset
Schizophrenia	≥2 psychotic symptoms, ≥1 must be delusions or hallucinations, lasting ≥6 months	~1%	Males 18–24, Females 24–35
Delusional Disorder	≥1 non-bizarre delusion(s) continuing ≥1 month	~0.003%	Late adulthood
Brief Psychotic Disorder	≥1 psychotic symptoms (≥1 must be delusions or hallucinations), lasting <1 month	~9% of all new psychosis cases	Males 18–24, Females 24–35
Schizoaffective Disorder	Manic or depressive episode concurrent with psychotic symptom(s)	~0.32%	Early adulthood
Catatonia	Behavioural abnormalities including motoric immobility or excitement; 20–50% of catatonia cases relate to mood disorders, 10% to schizophrenia	—	Early adulthood
Substance induced psychosis	Psychotic symptom onset traceable to starting/stopping a substance	~36.5% among methamphetamine misusers	Early adulthood
Schizophreniform Disorder	Same symptoms as schizophrenia, lasting >1 month and <6 months	~0.4–1%	Males 18–24, Females 18–24
Schizotypal PD	Difficulty forming/maintaining close interpersonal relationships plus eccentric behaviour	~3.9%	Late adolescence

A photograph of a person pressed against a wall in a fixed, unusual posture followed the classification slide when it was focused on catatonia, but the slide carried no caption or label, so its intended clinical point (presumably illustrating catatonic posturing) is not stated on the slide.

Assessment and screening

Psychosis is assessed for using:

• Medical exam
• Mental State Exam
• In-depth history
• Collateral information

Cautions during assessment:

• Consider culture-specific/appropriate phenomena
• Be aware of stigma
• Rule out other possible medical explanations
• Discuss with a colleague/superior

Differential diagnosis flowchart for confused or disturbed behaviour (Baumann, 2015):

1. Confused or disturbed behaviour → is there a fluctuating level of consciousness?
   • Yes → Delirium → toxic exposure? Yes → intoxication/withdrawal from substance abuse or prescribed medication. No → general medical conditions (e.g. infections, trauma, epilepsy, cardiovascular disorders, metabolic disorders, endocrine disorders, organ failure, deficiency states)
   • No → Cognitive impairment → since birth? Yes → intellectual disability. No → dementias
2. Also assess: psychotic symptoms present?
   • Yes → elevated or depressed mood? Yes → mania or agitated depression. No → schizophrenia spectrum disorders
   • No → pattern of disturbed behaviour since childhood/adolescence? Yes → conduct/personality disorders. No → reaction to stress/life events? Yes → PTSD/adjustment disorders/dissociative states. No → fear & panic/anxiety disorders/depression

Treatment and management

Management of psychosis and schizophrenia is multidisciplinary, spanning:

• Medication (pharmacotherapy): antipsychotics, antidepressants, mood stabilisers
• Psychological treatment (psychotherapy): CBT, family therapy, social skills training, group therapy, psycho-education
• Nursing
• Social work: social interventions
• Occupational therapy: occupational interventions, educational interventions
• Culture-specific interventions
• Spiritual interventions

Key summary points

• Psychotic spectrum disorders might be uncommon, but they do present in clinical practice.
• They are often highly distressing and debilitating conditions.
• Doctors need to know what they are, and be able to assess/screen, diagnose, and treat them or refer when they encounter them.
• Diagnosis can be challenging, as many symptoms can also present as part of other conditions, making screening and assessment critical for an accurate diagnosis.

Self-test

1. Define psychosis according to the APA.
2. List the five key features that define psychosis.
3. List the eight disorders under the DSM-5-TR’s Schizophrenia Spectrum and Other Psychotic Disorders category, including delusional disorder’s five subtypes.
4. State DSM-5-TR Criterion A for schizophrenia, and identify which symptoms alone are sufficient to help meet it.
5. Describe DSM-5-TR Criteria B, C, D, E and F for a diagnosis of schizophrenia.
6. List the DSM-5-TR course specifiers available for schizophrenia (used after 1 year of illness duration).
7. Describe how current severity is specified for schizophrenia.
8. List the four symptom clusters of schizophrenia, with one feature of each.
9. List the conditions that must be ruled out before diagnosing schizophrenia.
10. What was the prevalence of schizophrenia in NZ in 2015 overall, and how did it differ by ethnicity?
11. Describe how health, social, justice and economic outcomes differed between people with schizophrenia and a matched comparison population in the NZ cohort study.
12. Distinguish delusional disorder, brief psychotic disorder and schizophreniform disorder from schizophrenia in terms of duration and required symptoms.
13. Distinguish schizoaffective disorder from schizophrenia.
14. Describe catatonia, including its typical associations with other conditions.
15. List the four methods used to assess for psychosis, and the cautions to bear in mind while doing so.
16. A patient presents with confused, disturbed behaviour. Using the differential diagnosis flowchart, describe how you would distinguish delirium, dementia and a schizophrenia spectrum disorder as possible causes.
17. List the seven categories of treatment/management for psychosis and schizophrenia, with an example intervention from each.
18. Why is diagnosing psychotic spectrum disorders described as challenging, and why does this make screening and assessment critical?

Answers

Reveal answers

1. An abnormal mental state involving significant problems with reality testing, characterised by serious impairments or disruptions in the most fundamental higher brain functions (perception, cognition and cognitive processing, and emotions/affect), manifested behaviourally as delusions, hallucinations, and significantly disorganised speech.
2. Delusions; hallucinations; disorganized thinking (speech); grossly disorganized or abnormal motor behaviour (including catatonia); negative symptoms.
3. Schizotypal PD; Delusional Disorder (erotomanic, grandiose, jealous, persecutory, somatic subtypes); Brief Psychotic Disorder; Schizophreniform Disorder; Schizophrenia; Schizoaffective Disorder; Substance induced (psychotic disorder); Catatonia.
4. Two or more of: delusions, hallucinations, disorganized speech, grossly disorganized or catatonic behaviour, negative symptoms, each present for a significant portion of a 1-month period (or less if treated). At least one must be delusions, hallucinations, or disorganized speech.
5. B: functioning markedly below pre-onset level in a major area (work, interpersonal relations, self-care), or failure to reach expected level if childhood/adolescent onset. C: continuous signs for at least 6 months, including at least 1 month of active-phase symptoms, possibly with prodromal/residual periods of only negative or attenuated positive symptoms. D: schizoaffective disorder and mood disorder with psychotic features ruled out, as mood episodes were absent or present for only a minority of the illness duration. E: not attributable to a substance or another medical condition. F: with a history of autism spectrum disorder or childhood-onset communication disorder, schizophrenia is only additionally diagnosed if prominent delusions or hallucinations are present for at least 1 month alongside the other required symptoms.
6. First episode (acute/partial remission/full remission); multiple episodes (acute/partial remission/full remission); continuous; unspecified.
7. Each of delusions, hallucinations, disorganized speech, abnormal psychomotor behaviour, and negative symptoms is rated for its most severe presentation in the last 7 days on a 5-point scale from 0 (not present) to 4 (present and severe); this severity specifier is not required to make the diagnosis.
8. Reality distortion (delusions, hallucinations); psychomotor poverty (lack of effective responsiveness, loss of drive/volition, poverty of speech and movement); disorganisation (inappropriate affect, incoherent speech, disorganised behaviour); cognitive domain (impaired attention/concentration, memory/learning, executive functioning).
9. Delirium; dementia (especially in older patients); depression; medication side effects (e.g. sedation); learning disability; intoxication/withdrawal from psychoactive substances; psychosis due to a general medical condition; substance-induced psychotic disorder; culture-specific presentations/disorders; other mental disorders (delusional disorder, schizoaffective disorder, bipolar disorder, depressive disorder with psychotic features, schizophreniform disorder, brief psychotic disorder).
10. 18,096 people (6.7 per 1,000) in 2015. By ethnicity: European 6.3/1,000; Māori 16.7/1,000 (highest); Pacific 10.9/1,000; Asian 3.0/1,000.
11. People with schizophrenia had much higher mental health inpatient stays (12.2% vs 0.3%, OR 52.80) and ED visits, were far more likely to be on a welfare benefit (78.8% vs 17.4%, OR 17.64) and in social housing, had more police proceedings/convictions/prison sentences, were far less likely to be employed (27.6% vs 78.2%, OR 0.11), and had lower mean income ($17,865vs$44,092, $26,226lower)andgreaterdeprivation.Governmentcostswerehigheracrosshealth,socialsupportandjustice,totalling$32,795 vs $5,762 per person.
12. Delusional disorder: ≥1 non-bizarre delusion(s) for ≥1 month, no other required psychotic symptom. Brief psychotic disorder: ≥1 psychotic symptom (must include delusions or hallucinations) lasting <1 month. Schizophreniform disorder: same symptoms as schizophrenia but lasting >1 month and <6 months. Schizophrenia itself requires ≥6 months of continuous signs including ≥1 month of active symptoms.
13. Schizoaffective disorder involves a manic or depressive episode occurring concurrently with psychotic symptoms, whereas in schizophrenia mood episodes are absent, or present for only a minority of the total illness duration (per Criterion D).
14. Behavioural abnormalities that may include motoric immobility or excitement; among patients with catatonia, 20–50% of cases relate to mood disorders and 10% to schizophrenia; typical onset is early adulthood.
15. Medical exam, Mental State Exam, in-depth history, and collateral information. Cautions: consider culture-specific/appropriate phenomena, be aware of stigma, rule out other medical explanations, and discuss with a colleague/superior.
16. First check for a fluctuating level of consciousness: if present, this points to delirium (further split by toxic exposure into substance intoxication/withdrawal vs. general medical conditions such as infection, trauma, epilepsy, or metabolic/endocrine disorders). If cognitive impairment is present without fluctuating consciousness, check whether it has been present since birth (intellectual disability) or is acquired (dementia). Separately, if psychotic symptoms are present with no mood disturbance, this points towards a schizophrenia spectrum disorder (as opposed to mania/agitated depression if mood is elevated or depressed).
17. Medication (pharmacotherapy) — e.g. antipsychotics; psychological treatment (psychotherapy) — e.g. CBT; nursing; social work — social interventions; occupational therapy — occupational/educational interventions; culture-specific interventions; spiritual interventions.
18. Because many of the symptoms of psychotic spectrum disorders can also present as part of other conditions, making it hard to distinguish between diagnoses; this makes thorough screening and assessment essential for reaching an accurate diagnosis.