The global refugee crisis is a mental health catastrophe, leaving millions in need of psychological support to overcome the traumas of dislocation and conflict. To undo the damage, child psychiatrist and TED Fellow Essam Daod has been working in camps, rescue boats and the shorelines of Greece and the Mediterranean Sea to help refugees (a quarter of which are children) reframe their experiences through short, powerful psychological interventions. "We can all do something to prevent this mental health catastrophe," Daod says. "We need to acknowledge that first aid is not just needed for the body, but it has also to include the mind, the soul."

Public libraries have always been about more than just books -- and their mission of community support has taken on new urgency during the current opioid epidemic. After witnessing overdoses at her library in Philadelphia, Chera Kowalski learned how to administer naloxone, a drug that reverses the effects of narcotics, and she's put it to use to save patrons' lives. In this personal talk, she shares the day-to-day reality of life on the frontline of the opioid crisis and advocates for each of us to find new ways to keep our communities safe and healthy.

Is there someone in your life dealing with anxiety, depression or thoughts of suicide -- but is too ashamed to talk about it? Jeremy Forbes saw this happening around him, and now he's on a mission to teach people how to start a conversation about it. In this deeply personal talk, Forbes shares his approach to helping a group of traditionally silent men in his community open up about their struggles. "We can all be life preservers," he says.

Why do we still think that drug use is a law-enforcement issue? Making drugs illegal does nothing to stop people from using them, says public health expert Mark Tyndall. So, what might work? Tyndall shares community-based research that shows how harm-reduction strategies, like safe-injection sites, are working to address the drug overdose crisis.

Why do we still think that drug use is a law-enforcement issue? Making drugs illegal does nothing to stop people from using them, says public health expert Mark Tyndall. So, what might work? Tyndall shares community-based research that shows how harm-reduction strategies, like safe-injection sites, are working to address the drug overdose crisis.

Thousands of years ago, ancient Nubians drew pictures on tomb walls of a terrible disease that turns the eyelids inside out and causes blindness. This disease, trachoma, is still a scourge in many parts of the world today -- but it's also completely preventable, says Caroline Harper. Armed with data from a global mapping project, Harper's organization Sightsavers has a plan: to focus on countries where funding gaps stand in the way of eliminating the disease and ramp up efforts where the need is most severe. Learn more about their goal of consigning trachoma to the history books -- and how you can help. (This ambitious idea is part of the Audacious Project, TED's initiative to inspire and fund global change.)

Irina Kareva translates biology into mathematics and vice versa. She writes mathematical models that describe the dynamics of cancer, with the goal of developing new drugs that target tumors. "The power and beauty of mathematical modeling lies in the fact that it makes you formalize, in a very rigorous way, what we think we know," Kareva says. "It can help guide us to where we should keep looking, and where there may be a dead end." It all comes down to asking the right question and translating it to the right equation, and back.

Four decades ago, Judith Heumann helped to lead a groundbreaking protest called the Section 504 sit-in -- in which disabled-rights activists occupied a federal building for almost a month, demanding greater accessibility for all. In this personal, inspiring talk, Heumann tells the stories behind the protest -- and reminds us that, 40 years on, there's still work left to do.

What if we incentivized doctors to keep us healthy instead of paying them only when we're already sick? Matthias Müllenbeck explains how this radical shift from a sick care system to a true health care system could save us from unnecessary costs and risky procedures -- and keep us healthier for longer.

We use rituals to mark the early stages of our lives, like birthdays and graduations -- but what about our later years? In this meditative talk about looking both backward and forward, Bob Stein proposes a new tradition of giving away your things (and sharing the stories behind them) as you get older, to reflect on your life so far and open the door to whatever comes next.