Background

Survivors of natural disasters are thought to be at an increased risk of psychiatric disorders, however the extent of this risk, and whether it is linked to pre-existing psychopathology, is not known. We aimed to establish whether Swedish survivors of tsunamis from the 2004 Sumatra–Andaman earthquake had increased risks of psychiatric disorders and suicide attempts 5 years after repatriation.

Methods

We identified Swedish survivors repatriated from southeast Asia (8762 adults and 3742 children) and 864 088 unexposed adults and 320 828 unexposed children matched for sex, age, and socioeconomic status. We retrieved psychiatric diagnoses and suicide attempts from the Swedish patient register for the 5 years after the tsunami (from Dec 26, 2004, to Jan 31, 2010) and estimated hazard ratios (HRs), then adjusted for pre-tsunami psychiatric disorders, and, for children, for parental pre-tsunami disorders.

Findings

Exposed adults were more likely than unexposed adults to receive any psychiatric diagnosis (547 [6.2%] vs 47 734 [5.5%]; adjusted HR 1.21, 95% CI 1.11–1.32), particularly stress-related disorders (187 [2.1%] vs 8831 [1.0%]; 2.27, 1.96–2.62) and suicide attempts (38 [0.43%] vs 2752 [0.32%]; 1.54, 1.11–2.13), but not mood or anxiety disorders. Risk of psychiatric diagnoses did not differ between exposed and unexposed children and adolescents (248 [6.6] vs 22 081 [6.9%]; 0.98, 0.86–1.11), although exposed children and adolescents had a higher risk for suicide attempts with uncertain intent (1.43; 1.01–2.02) and stress-related disorders (1.79; 1.30–2.46), mainly during the first 3 months after the tsunami.

Interpretation

The 2004 tsunami was, independently of previous psychiatric morbidity, associated with an increased risk of severe psychopathology, mainly stress-related disorders and suicide attempts, in children and adults. Survivors of natural disasters should be targeted with early interventions and active long-term follow-up to prevent, detect, and alleviate psychiatric disorders that might follow.