PSYCHOLOGY 5: Psychotic Disorders (Beyond Schizophrenia)

Advanced Psychology ESL – Symptom Structure, Differential Diagnosis & Treatment Models

1. Introduction

Psychotic disorders involve significant disruptions in:

  • perception

  • thought processes

  • reality testing

  • behaviour

Psychosis can develop gradually (prodromal phase) or appear suddenly.
It can be caused by:

  • primary psychiatric disorders

  • neurological or medical conditions

  • substances

  • extreme stress or trauma

Psychosis is a syndrome, not a single diagnosis. Each disorder has unique patterns.

2. Core Symptoms of Psychosis

A person is considered psychotic when experiencing one or more of the following:

Hallucinations

Perceptions without an external stimulus
— most common: auditory (voices), but also visual, tactile, olfactory.

Delusions

Fixed false beliefs resistant to evidence.
Types include:

  • persecutory

  • grandiose

  • erotomanic

  • somatic

  • referential (“TV/radio sending messages”)

Disorganized Thinking

  • tangential or loose associations

  • derailment

  • incoherence (“word salad”)

Grossly Disorganized or Catatonic Behaviour

  • agitation or unpredictability

  • rigid posturing

  • mutism

  • motor disturbances

Negative Symptoms

  • blunted affect

  • avolition (lack of motivation)

  • alogia (reduced speech)

  • anhedonia

  • social withdrawal

Important: Psychosis is a symptom cluster — it appears in many disorders, not only schizophrenia.

3. Schizoaffective Disorder

A hybrid disorder combining psychosis + mood episodes.

Diagnostic Structure

To diagnose schizoaffective disorder:

  1. A major mood episode (depressive or manic) occurs with psychotic symptoms.

  2. There must be ≥2 weeks of psychosis without mood symptoms.

  3. Mood symptoms are present for the majority of the illness duration.

Differentiation

  • vs Bipolar Disorder with Psychosis:
    Psychosis occurs only during mood episodes.

  • vs Schizophrenia:
    Mood symptoms are brief or secondary.

Treatment

  • antipsychotics

  • mood stabilisers

  • psychotherapy targeting relapse prevention, coping skills, medication adherence

4. Brief Psychotic Disorder

A sudden onset of psychosis lasting:

  • ≥ 1 day

  • < 1 month

  • with full return to baseline

Often triggered by:

  • severe stress

  • trauma

  • significant life changes

Symptoms

May include hallucinations, delusions, disorganization, or catatonia.

Treatment

  • short-term antipsychotics

  • close monitoring

  • addressing precipitating stressors

Prognosis is excellent when treated early.

5. Delusional Disorder

Characterized by one or more persistent delusions lasting ≥ 1 month.

Key Features

  • functioning outside the delusion is relatively intact

  • behaviour is not markedly bizarre

  • hallucinations are minimal or absent

Delusion Types

  • persecutory

  • jealous

  • erotomanic

  • grandiose

  • somatic

  • mixed

Treatment

  • antipsychotics

  • CBT to challenge delusional beliefs

  • careful therapeutic alliance (patients may mistrust clinicians)

6. Substance/Medication-Induced Psychotic Disorder

Psychosis directly caused by:

Substances

  • methamphetamine

  • cocaine

  • high-THC cannabis

  • LSD, PCP

  • steroids

  • stimulants

Withdrawal

  • alcohol withdrawal

  • benzodiazepine withdrawal

Treatment

  • stop the substance

  • manage withdrawal

  • antipsychotics if symptoms persist

  • long-term addiction support

Substance-induced psychosis can resolve, but repeated episodes increase long-term risk.

7. Psychotic Disorder Due to a Medical Condition

Medical causes must always be ruled out before diagnosing a primary psychotic disorder.

Possible Causes

  • epilepsy (especially temporal lobe)

  • brain tumours

  • autoimmune encephalitis

  • major infections

  • metabolic disturbances

  • endocrine abnormalities (thyroid, adrenal)

  • Parkinson’s or Alzheimer’s disease

  • Wilson’s disease

Diagnosis requires clear evidence that psychosis is directly caused by the medical condition.

**8. Catatonia

(Can occur in schizophrenia, mood disorders, or medical conditions)**

Symptoms

  • stupor

  • mutism

  • posturing

  • negativism

  • waxy flexibility

  • agitation

  • echolalia / echopraxia

Treatment

  • lorazepam challenge (benzodiazepines)

  • ECT for severe cases
    Untreated catatonia can be life-threatening.

9. Biological Mechanisms of Psychosis

Dopamine Dysregulation

  • Mesolimbic pathway ↑ dopamine → positive symptoms

  • Mesocortical pathway ↓ dopamine → negative symptoms, cognitive impairment

Glutamate Dysfunction

NMDA receptor hypofunction → impaired learning, memory, and executive functioning.

Structural Differences

  • enlarged ventricles

  • reduced grey matter

  • abnormal functional connectivity

  • impaired sensory gating

Stress–Vulnerability Model

Psychosis emerges when:

genetic predisposition + environmental stress + neurobiological changes
overwhelm coping capacity.

10. Treatment of Psychotic Disorders

Medication

  • Typical antipsychotics (D2 antagonists; effective for positive symptoms)

  • Atypical antipsychotics (dopamine + serotonin modulation; better for negative symptoms)

Psychotherapy

  • CBT for psychosis (CBTp)

  • psychoeducation

  • relapse-prevention strategies

  • stress management

Social and Functional Interventions

  • skills training

  • supported employment

  • family therapy

  • community teams

Early Intervention

Critical for preventing:

  • cognitive decline

  • functional deterioration

  • recurrent episodes

11. Key Academic Vocabulary

reality testing
thought disorder
positive symptoms
negative symptoms
hallucination
delusion
affective component
catatonia
NMDA receptor
dopamine pathway
prodromal phase
brief psychosis
schizoaffective pattern
first-episode psychosis

12. Discussion Questions

  1. How does schizoaffective disorder differ from schizophrenia and bipolar disorder?

  2. Why can extreme stress trigger brief psychotic disorder?

  3. Why is delusional disorder challenging to treat therapeutically?

  4. Which substances most commonly induce psychosis, and why?

  5. How do dopamine pathways explain positive vs negative symptoms?

  6. Why is early treatment essential in psychotic disorders?

  7. What medical conditions must be ruled out before diagnosing primary psychosis?

13. Scientific Expansion: Psychosis & Brain Function

Predictive Coding Error

The brain constantly predicts sensory input.
In psychosis, prediction errors cause:

  • assigning meaning where none exists

  • misinterpreting internal thoughts as external voices

  • perceptual instability

Aberrant Salience

Excess dopamine → ordinary events feel significant or threatening.

Impaired Reality Monitoring

Difficulty distinguishing:

  • internal vs external stimuli

  • thoughts vs perceptions

14. Case Studies (Short, Clinical, Non-Worksheet)

Case Study A — First-Episode Psychosis

A 19-year-old begins hearing voices commenting on her actions, becomes socially withdrawn, and displays disorganized speech. No substance use. Functioning drops sharply.

Teaching Focus:

  • schizophrenia vs mood disorders

  • importance of early intervention

  • dopamine pathway involvement

Case Study B — Brief Psychotic Disorder

A 35-year-old mother experiences sudden delusions after a traumatic event. Symptoms resolve fully within 3 weeks.

Teaching Focus:

  • stress-triggered psychosis

  • short-term prognosis

  • differentiation from schizophrenia

Case Study C — Delusional Disorder (Jealous Type)

A 42-year-old man believes his partner is unfaithful despite lacking evidence. Functioning at work remains normal. No hallucinations.

Teaching Focus:

  • delusional disorder vs paranoia in schizophrenia

  • treatment challenges

  • maintaining therapeutic alliance

Case Study D — Substance-Induced Psychosis

A 24-year-old presents with paranoia and auditory hallucinations after chronic cannabis + methamphetamine use.

Teaching Focus:

 

  • substance effects

  • differential diagnosis

  • recovery trajectory