4a: Schizophrenian& psychosis

Core Definitions and Frameworks

• Psychosis: A mental state involving a loss of contact with reality; it is a symptom of various conditions rather than a standalone disorder.

  • characterised by hallucinations and delusions

• Schizophrenia: A chronic syndrome involving disturbances in thought, perception, emotion, and behavior.

• The Psychotic Spectrum: Psychotic experiences exist on a continuum of severity, ranging from schizoid traits to schizophrenia and schizoaffective disorder.

• Biopsychosocial Aetiology: Disorders result from complex interactions between biological (genetic/neurological), psychological (stress/coping), and social (environmental/cultural) factors.

defining psychosis: Symptomatology

• a collections of symptoms that affect the mind, where there has been some loss of contact with reality

• beliefs and experiences that are not shared by other people

• impacts a person’s sense of what is real and what isn’t

• Positive Symptoms: Additional disturbances including hallucinations, delusions, disordered thought, and abnormal motor behavior.

• Negative Symptoms: Diminished functioning such as affective flattening, anhedonia, alogia, avolition, and social withdrawal.

• Hallucination Mechanisms: auditory, visual, olfactory (smells without a source) gustatory (flavours without substance), tactile (sensation on skin without stimuli)

  • Metacognition: Impaired self-awareness and difficulty monitoring cognitive processes.  

  • Perception Misattribution: Incorrectly labeling internal imagery as external experience.   

  • Efference Copy Model (Corollary Discharge Theory): Brain dysfunction in predicting sensory consequences of motor commands.

• Delusion Categories: fixed, false beliefs held with strong conviction despite clear evidence to the contrary, and are not explained by cultural or religious background

  • Non-Bizarre: Theoretically possible (e.g., being followed).     

  • Bizarre: Utterly impossible (e.g., thoughts being broadcasted).     

  • Specific Types: Persecutory, Referential (ideas of reference), Grandiose, Somatic, Religious, Thought Alienation, and Misidentification.

Schizophrenia

• umbrella term

• complex syndrome characterised by dysfunctions

• domains:

  • cognitive: thinking, concentraion

  • perceptual: hallucinations

  • behavioural: disorganised actions

  • language: speech, thought expression

  • emotional: challenges with expressing emotions, inappropriate emotional reactions

Epidemiology and Developmental Course - Schizophrenia

• Prevalence: Affects approximately $1\text{--}2\%$ of the global population.

• Demographics: Slightly more common in males; typical onset is late teens to mid-twenties.

• Clinical Stages:     

  • Premorbid Phase: Subtle neurodevelopmental changes and social withdrawal.     

  • Prodromal Phase: Attenuated psychotic symptoms and functional impairment. negative symptoms

  • Acute Phase: Full manifestation of positive symptoms and disorganized speech.     

  • Recovery Phase: Early (stabilization) and Late (relapse prevention/quality of life). reduction in positive symptoms

• Ageing Impacts: Increased risk of cognitive decline, physical comorbidities (cardiovascular, metabolic), and premature mortality.

DSM-5 Diagnostic Criteria and Differentials

• Criterion A (Active-Phase Symptoms): Minimum of two symptoms for a significant portion of $1\,\text{month}$. At least one must be Delusions, Hallucinations, or Disorganised Speech.

• Criterion B: marked decrease in functioning

• Criterion C: persistent signs of disturbance, duration of at least 6 months, with at least 1 month of active-phased symptoms

• Differential Diagnosis:     

  • Bipolar Disorder: Differentiated by the timing of mood episodes; psychotic symptoms are often mood-congruent.     

  • Substance/Medical: Must rule out intoxication, withdrawal, or endocrine/neurological conditions.     

  • Developmental: Must evaluate for Autism Spectrum Disorder (ASD).

• Specifiers: Include course (First Episode, Multiple Episodes, Continuous) and presence of Catatonia.

  • unspecified: when the course cannot be determined

  • other specifiers

  • catatonia

  • severity

Related Psychotic Disorders

• Brief Psychotic Disorder: Symptoms lasting $1\,\text{day}$ to $1\,\text{month}$.

• Schizophreniform Disorder: Symptoms lasting $1$ to $6\,\text{months}$.

• Schizoaffective Disorder: Schizophrenia features accompanied by a significant mood disorder.

• Schizophrenia: symptoms lasting longer than 6 months

other psychotic disorders

• Delusional Disorder: One or more delusions for $1\,\text{month}$ or longer without markedly impaired functioning.

• Shared Psychotic Disorder: Delusion develops in an individual due to close association with someone who has an established delusion.

spectrum

1. schizoid personality disorder: introverted, voluntary withdrawal from social interactions

2. schiotypal personality disorder: schizoid traits + magical thinking and odd behaviour

3. schizophrenia: schizotypal traits + psychosis

4. schizoaffective disorder

   • schizophrenia + significant mood disorder