After a hurricane, flood, wildfire, or other disaster strikes, a great tallying commences: the number of people injured and killed; buildings damaged and destroyed; acres of land burned, inundated, or contaminated. Every death is recorded, every insured home assessed, the damage to every road and bridge calculated in dollars lost. When the emergency recedes, the insurance companies settle their claims, and the federal government doles out its grants, communities are expected to rebuild. But the accounting misses a crucial piece of the aftermath: Worsening disasters are leaving invisible mental health crises in their wake.

A handful of studies have sought to quantify the scope and scale of the mental health consequences of disasters that have occurred in the recent past, such as Hurricane Andrew in 1992, Hurricane Katrina in 2005, and Hurricane Irma in 2017. The results point to an alarming trend: The stress and trauma of losing a loved one, seeing a home destroyed, or watching a beloved community splinter has resounding mental health repercussions that stretch on for months, even years, after the disaster makes its first impact and can include anxiety, depression, sleep disorders, post-traumatic stress, and sometimes suicidal ideation and suicide follow disasters.

Children and adolescents — who are still learning to regulate their emotions, rely on routine and a sense of safety more than most adults do, and get social and mental stimulation from interacting with peers — are among the demographics most vulnerable to the chaos and isolation brought on by extreme weather events.

A study published in mid-January in the Journal of Traumatic Stress analyzed survey data from more than 90,000 public school students across Puerto Rico in the months following Hurricane Maria’s landfall in September 2017. Maria, a Category 5 storm that caused widespread destruction in the northern Caribbean, killed nearly 3,000 people in Puerto Rico and caused mass blackouts that left huge portions of the island without electricity and drinking water for months — a reflection of decades of disinvestment in and mismanagement of the island’s infrastructure.

Some 30 percent of the students surveyed five to nine months after the hurricane made landfall said they felt their lives were threatened by the storm, 46 percent said their homes were significantly damaged, and 17 percent said they were injured or a family member was injured.

Roughly 7 percent of the young people surveyed — about 6,300 students — developed symptoms of post-traumatic stress disorder, or PTSD, after the storm. For this subset, the psychological consequences of living through Maria and its aftermath were extreme.

Read the full article about children's mental health after climate disasters by Zoya Teirstein at Grist.