(Attenuated) hallucinations join basic symptoms in a transdiagnostic network cluster analysis

Area of Science:

• Psychiatry
• Clinical Psychology
• Network Analysis

Background:

• Hallucinations are key psychosis symptoms and part of the Hierarchical Taxonomy Of Psychopathology (HiTOP) psychosis superspectrum.
• Understanding the psychopathological relevance of hallucinations requires dimensional placement within transdiagnostic symptom networks.

Purpose of the Study:

• To investigate the dimensional placement of hallucinations within a dense transdiagnostic network of basic, attenuated, and frank psychotic symptoms.
• To explore symptom clustering and the role of insight in differentiating hallucinatory experiences.

Main Methods:

• Utilized Newman's modularity analysis on an existing network of 86 symptoms.
• Assessed symptoms using the Schizophrenia Proneness Instrument, Adult version (SPI-A), Structured Interview for Psychosis-Risk Syndromes (SIPS), and Positive And Negative Syndrome Scale (PANSS).
• Analyzed data from three adult samples: clinical high-risk (n=203), first-episode psychosis (n=153), and major depression (n=104).

Main Results:

• Identified three distinct symptom clusters: 'subjective disturbances,' 'positive symptoms and behaviors,' and 'negative and anxious-depressive symptoms.'
• Attenuated hallucinations (from SIPS and PANSS) clustered with basic symptoms in 'subjective disturbances.'
• Frank positive symptoms grouped into 'positive symptoms and behaviors,' differentiating them from attenuated experiences.

Conclusions:

• Insight is crucial for distinguishing true psychotic hallucinations from attenuated experiences.
• Hallucinations experienced with any degree of insight should not solely diagnose frank psychosis or justify antipsychotic medication.