Auditory hallucinations across the lifespan: a systematic review and meta-analysis

Background. Auditory Hallucinations (AH) are nowadays regarded as symptoms following a continuum; from a (transient) phenomenon in healthy individuals on one end to a symptom of (psychiatric) illnesses at the other. An accumulating number of epidemiological studies focused on the prevalence of AH in the general population, but results vary widely. The current meta-analysis aims to synthesize existing evidence on lifetime prevalence of AH across the lifespan. Methods. We conducted a quantitative review and meta-analysis according to PRISMA guidelines. Studies were combined to calculate a mean lifetime general population AH prevalence rate. Moreover, prevalences were calculated for four age groups: children (5-12 years), adolescents (13-17 years), adults (18-60 years) and elderly (60 years). Results. We retrieved 25 study samples including 84 711 participants. Mean lifetime prevalence rate of AH was 9.6% (95% CI 6.7-13.6%). The mean lifetime prevalence was similar in children (12.7%) and adolescents (12.4%), but these two groups differed significantly from the adults (5.8%) and the elderly (4.5%). Significant heterogeneity indicated that there is still dispersion in true prevalence rates between studies, even within the different age categories. Conclusions. Current meta-analysis shows that AH are quite common (up to one in ten individuals) in the general population during lifetime, with children and adolescents reporting these experiences significantly more often compared with adults and elderly. Large follow-up studies on the longitudinal course of AH are needed to reveal associated risk and resilience factors.