One of the scariest parts of advanced macular degeneration can be losing the ability to read facial expressions. Maria Pavlova /iStockphoto hide caption

itoggle caption Maria Pavlova /iStockphoto

Teenagers' sleep patterns may be a clue to their risk of depression. iStockphoto hide caption

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Girls are particularly vulnerable to brain changes caused by stress or trauma, researchers say. Allen Johnson/iStockphoto.com hide caption

itoggle caption Allen Johnson/iStockphoto.com

Older men may have guns in the home that can pose a risk when people are depressed or not thinking clearly. iStockphoto.com hide caption

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Depression is common among old people, affecting up to 25 percent. iStockphoto.com hide caption

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Having a special someone won't fend off depression if that person doesn't have your back. iStockphoto.com hide caption

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Meredith Was, a senior at the University of Virginia, heads a chapter of the mental health advocacy group Active Minds. Jenny Gold for NPR hide caption

itoggle caption Jenny Gold for NPR