Abstract
BACKGROUND: Compared to active ideation, passive ideation remains relatively understudied and its clinical importance poorly defined. The weight that should be accorded passive ideation in clinical risk assessment is therefore unclear. METHODS: We conducted a systematic review and meta-analysis of the prevalence of passive ideation, its psychiatric comorbidity, associated sociodemographic characteristics, as well as psychological and environmental correlates. For reference, pooled effects were also calculated for direct comparisons of passive and active ideation with respect to potential correlates. Relevant articles published since inception to 9 September 2019 were identified through a systematic search of MEDLINE and PsycINFO. RESULTS: A total of 86 studies were included in this review. The prevalence of passive ideation was high across sample types, ranging from 5.8% for 1-year prevalence to 10.6% for lifetime prevalence in the general population. Passive ideation was strongly associated with sexual minority status, psychiatric comorbidity, psychological characteristics implicated in risk, and suicide attempts. Preliminary evidence exists for a large association with suicide deaths. The effect sizes for individual correlates of passive and active ideation were largely equivalent and mostly non-significant in head-to-head comparisons. CONCLUSIONS: Passive ideation is a prevalent clinical phenomenon associated with significant psychiatric comorbidity. Current evidence also suggests notable similarities exist between passive and active ideation in terms of psychiatric comorbidity and psychological and other characteristics traditionally associated with risk.