Natural disasters and suicidal behaviour: an updated systematic review

Background: This systematic review aims to update and extend the findings of an earlier review on the suicidogenic impact of natural disasters.Methods: A systematic search of research published in 17 bibliographic databases was conducted (PROSPERO CRD42020216722). The review following PRISMA checklist identified 64 primary studies, published between 2012 and 2022, investigating the association between natural disasters and suicidal behaviour and ideation.Results: The majority of studies related to natural disasters in Japan, China, USA, India and Australia. Over half the studies (n=39) investigated the impact of earthquakes. Other disasters included hurricanes, floods, tsunamis, droughts, wildfires, tornadoes and multiple disasters. Concerning suicide mortality (the most studied suicide-related outcome), there was variability in the suicidogenic impact of earthquakes depending on location, age, sex and time elapsed since the event. While there appeared to be an increase in suicide mortality following drought, investigations of hurricanes/tornadoes and floods found no evidence of suicidogenic impact. Findings relating to other suicide-related outcomes are more consistent, suggesting that exposure to droughts, hurricanes, tsunamis, floods, and other natural disasters is associated with increased risk of suicidal ideation and non-fatal suicidal behaviour. Limitations: Publications in languages other than English, French, Spanish, Italian and Portuguese may have been missed.Conclusions: The considerable inconsistency in the findings reported across these studies, particularly relating to suicide mortality, is noteworthy. This may reflect substantive (‘real’) differences in the impact of natural disasters on suicidal behaviour linked to the type of disaster, the socioeconomic and sociocultural context, the type of suicidal behaviour, or other explanatory factors.