Her symptoms – nausea, insomnia and a loss of appetite – didn’t require medical attention. However, in the days following the quake, the young girl’s parents decided to seek help, after hearing doctors were seeing patients affected by the disaster at a government building in downtown Xochimilco, one of Mexico City’s hardest-hit districts. The doctors referred her to a psychologist – one of many who mobilised to help the country’s children and distressed adults cope with the aftermath.

Typically, much of the mental health support that victims receive after natural disasters comes months after the event, if at all, and after basic needs are first met. But what’s changing in Mexico is that now counsellors and psychologists are moving much faster to help people immediately. Last week, hundreds of them offered free counselling in shelters at government buildings and via hotlines within hours of the quake.

The trauma of the event is likely to take a toll on many residents – not just those who lost loved ones, but people who were evacuated from buildings, felt an earthquake for the first time or remembered the devastation of the 1985 earthquake, as well as the hundreds of volunteers who rallied to help in the relief efforts. To cope with the aftermath of a disaster, survivors usually go through a process of disbelief, bewilderment, difficulty focusing, denial, anxiety, fear and eventually depression and sadness, according to researchers.

Yet if the world can learn from what happened in Mexico last week, it’s that intervening faster to offer immediate mental health assistance may be key to helping people deal with trauma in the longer-term – and particularly for children like Barrera.