After a cyclone hits India's coast, psychiatric medicine sales jump for a year

In India's coastal districts, sales of medicines used to treat mental disorders rose 144% in the year a tropical cyclone made landfall, and 173% the year after, a study spanning five years of storms found [s1]. Inland districts showed no statistically significant change, evidence that the psychiatric toll of these storms is concentrated where they strike hardest and lingers well past the day the wind drops [s1].

A different way to see a hidden harm

Mental-health effects of disasters are notoriously hard to measure: surveys are expensive, memories shift, and the people worst affected are often the hardest to reach. This study used a proxy that sidesteps some of that. Researchers assembled a novel dataset of sales of selected mental-disorder treatment medicines across Indian districts, then linked it to the landfall and inland penetration of cyclones between April 2018 and March 2023 [s1]. The unit of analysis was the district-year, and the model was an autoregressive distributed lag specification with fixed effects, which controls for stable district characteristics and for shocks common to a given year [s1].

The design's strength is that it asks about medicine actually purchased rather than symptoms self-reported, and it can separate contemporaneous from delayed effects. Its results were consistent with a real, geographically bounded impact: cyclone occurrence raised medicine sales by 144% in coastal districts in the landfall year, and the one-year-lagged effect was stronger still, at 173% higher sales [s1]. The effect then weakened over time [s1].

Where the burden falls — and where it doesn't

The geography is the most telling part. The study found no statistically significant cyclone effect in non-coastal districts, while in coast-adjacent districts the impact appeared only after a longer lag [s1]. That gradient — sharp on the coast, delayed just inland, absent further in — is what you would expect if the mechanism is direct exposure to the storm and its aftermath rather than generalised anxiety about the weather. The authors note that coastal communities already carry relatively greater climate risk, and that this mental-health burden compounds it [s1].

The delayed peak matters for how systems respond. A toll that is higher a year after the storm than during it cuts against the usual model of disaster relief, which surges in the days and weeks after landfall and then withdraws. If the heaviest demand for mental-health care arrives twelve months later, the response window most services are built around closes before the need peaks.

It fits the broader evidence

A 2025 systematic review of climate change and mental health in vulnerable groups puts the cyclone finding in context. Screening 1,197 articles and including 32, it found that most studied acute weather events, and that the commonest documented outcomes were post-traumatic stress symptoms or disorder (in 15 studies) and depressive disorder (12 studies) [s2]. The research concentrated on low-socioeconomic-status groups (26 studies) and minoritised ethnic or racial groups (12 studies), with very little on Indigenous or housing-insecure populations [s2]. The through-line is that acute climate-driven disasters leave a measurable psychiatric mark, and that it falls hardest on those with the fewest resources to absorb it — the same populations that dominate India's exposed coastlines [s2].

What it does not show

Medicine sales are a proxy, not a diagnosis. They can rise because more people fall ill, because existing patients fill prescriptions they had delayed, or because supply and prescribing patterns shift after a disaster; the study cannot fully separate these, and it measures treatment, not the untreated need that is often larger [s1]. Aggregated district-year data also cannot follow individuals, so the design shows a population-level association, not a causal path in any one person [s1]. The systematic review, for its part, is a narrative synthesis of heterogeneous studies and stops short of a pooled effect size [s2].

What to watch

The practical question is whether mental-health provision in cyclone-exposed regions is timed to the harm the data describe — sustained through the year after a storm rather than concentrated in the fortnight after it. Whether disaster-response frameworks begin to treat delayed psychiatric demand as a predictable, plannable consequence of landfall, the way they already plan for shelter, water and infectious disease, is the shift this line of evidence is pushing toward.

Sources

1. [s1] The toll of the cyclone: mental health impacts of tropical cyclones in coastal communities of India. BMC Public Health, December 13, 2025. https://doi.org/10.1186/s12889-025-25939-4
2. [s2] The impact of climate change on mental health in vulnerable groups: a systematic review. BMC Psychology, October 31, 2025. https://doi.org/10.1186/s40359-025-03497-z