Whether wearing white lab coats, red rescue worker vests or dressed as clowns, the psychologists standing by as Mexico picks through the rubble of this week's earthquakes are ready to help a shaken nation deal with its trauma.   Whole brigades of volunteer psychologists have deployed to the collapsed buildings in Mexico City where anguished families are clinging to the fading hope that their loved ones are alive inside.   Exhausted rescuers are still working around the clock to untangle the wreckage, despite the fact that the crucial 72-hour window for finding survivors from Tuesday's quake has closed.   "The families still have hope, but we psychologists are starting to prepare ourselves to counsel them in the context of mourning," said Penelope Exzacarias at a collapsed office building in Mexico City's trendy Roma neighborhood.   Wearing a red vest marked with the word "Psychologist," Exzacarias was on hand to support victims' families -- mainly by listening.   "With every passing minute, hope is diminishing for them. It's a very painful moment," she told AFP.   - 'The trauma comes after' -   The psychologists are also on hand to help the thousands of rescue workers, many of them volunteers, who have been grappling with the rubble for days The psychologists are also on hand to help the thousands of rescue workers, many of them volunteers, who have been grappling with the rubble since Tuesday.   "It's hard to work non-stop for so long and to see a dead body, even if you're used to it," said Lorena Villalpando, another psychologist at the scene wearing a red vest and orange helmet declaring her profession.   Mexico's trauma is all the greater because the tragedy struck on the anniversary of the worst earthquake in its history, which killed more than 10,000 people in 1985.   Even for people not directly affected by the destruction in this sprawling city of 20 million people, there can be lasting trauma, said Alan Schejtman Deutsch of the Mexican Psychoanalytical Association, who is coordinating the brigades of volunteer psychologists.   "Right now, people are very active, trying to get (victims) out, to clear the rubble, but experience shows that post-traumatic stress hits after several days or weeks," he said.   - Children at risk -   Therapists dressed as clowns have taken to the streets of Mexico City to both entertain children and inform their parents about the importance of dealing with possible trauma A specialist clinic in the nearby neighborhood of Condesa was signing up volunteer psychologists to counsel residents of the hard-hit district.   The most common symptoms of PTSD they were seeing: "constantly reliving the moment of trauma in your mind, a high level of anxiety, trouble sleeping, lack of appetite," said Schejtman.   Children are at risk too, he emphasized.   "Children actually suffer much worse because they assimilate all this information in a completely different way. They don't really understand what's happening... and death is a subject they understand even less," he said.   In response, therapists dressed as clowns have taken to the streets of Mexico City to both entertain children and inform their parents about the importance of dealing with possible trauma.   - Mother and daughter -   Marcela Cardoso Miranda was seven years old when the 1985 earthquake hit.   Thirty-two years on, she relived the trauma as a parent, crossing the city in search of her daughter, age seven herself.   "A lot of us lived through '85, and because of that experience, today, memories of our loss, whether direct or indirect, material or physical, are surging back to the surface," said Cardoso, herself a psychologist volunteering at the Condesa clinic.   "We're living in a climate of stress, depression, uncertainty, and even if the city seems to be returning to normal in some places, the reality is that there is a collective feeling of loss, that there's been a disaster."   But that sense of loss has also given rise to remarkable solidarity.   "We have been overwhelmed by this outpouring of people helping each other, something we don't manage to do the rest of the time," Cardoso said.