Hallucinations and Trauma in one’s Childhood, Adulthood and Lifetime: Mapping Prevalence, Probability, and Phenomenology in Clinical and Nonclinical Populations

Chapter One: Systematic Review

Background: It is well documented that childhood trauma increases hallucination risk, but less is understood about adulthood trauma (AT).

Aim: To systematically review and critically appraise research on hallucinations reported by AT survivors and identify the AT they survived.

Method: Four databases (CINHAL, PubMed, Web of Science, PsycINFO) were searched.

After selecting studies, an integrated mixed methods synthesis was used.

Results: Fourteen observational studies with 12,647 participants were included. Adulthood traumas included experiencing abuse, war and persecution, natural disaster and being held hostage. Hallucination experiences varied in modality, trauma-relatedness, and temporal qualities.

Discussion: Implications include integrating lifespan and trauma-informed perspectives into research and healthcare. Evidence is constrained by retrospective designs and samples biased towards white and male participants.

Chapter Two: Empirical Study

Objectives: This study aimed to investigate the prevalence of current hallucinations and prior abuse, and the statistical relationships between these, at routine early intervention in psychosis service (EIPS) assessments.

Methods: Using a secondary data analysis design, an anonymised chart review dataset (n=134 adults) was analysed to explore prevalence and probabilities.

Results: Historical abuse was reported during 76% of assessments. Prevalence of childhood physical and sexual abuse were aligned with ‘psychosis’ meta-analyses. A higher odds-ratio of concurrent hallucinations was observed for abuse survivors, than people who did not disclose abuse; this odds ratio varied by abuse subtype, life-stage during abuse exposure, and hallucination modality studied. 

Conclusions: A nuanced relationship between historical abuse exposure and concurrent hallucinations was observable at routine EIPS assessments. Existing evidence on hallucinations and abuse were relevant to routine care.