Watch these recommended TED-Ed Lessons and TED Talks:

A brief history of melancholy
If you are a living, breathing human being, chances are you have felt sad at least a few times in your life. But what exactly is melancholy, and what (if anything) should we do about it? Courtney Stephens details our still-evolving understanding of sadness -- and even makes a case for its usefulness.

Why do we cry? The three types of tears
Whether we cry during a sad movie, while chopping onions, or completely involuntarily, our eyes are constantly producing tears. Alex Gendler tracks a particularly watery day in the life of Iris (the iris) as she cycles through basal, reflex and emotional tears.

What is depression?
Depression is the leading cause of disability in the world; in the United States, close to ten percent of adults struggle with the disease. But because it’s a mental illness, it can be a lot harder to understand than, say, high cholesterol. Helen M. Farrell examines the symptoms and treatments of depression, and gives some tips for how you might help a friend who is suffering.

How to connect with depressed friends
Want to connect with a depressed friend but not sure how to relate to them? Comedian and storyteller Bill Bernat has a few suggestions. Learn some dos and don'ts for talking to people living with depression -- and handle your next conversation with grace and maybe a bit of humor.

Why do we feel nostalgia?
Nostalgia was once considered an illness confined to specific groups of people. Today, people all over the world report experiencing and enjoying nostalgia. But how does nostalgia work? And is it healthy? Clay Routledge details the way our understanding of nostalgia has changed since the term was first coined in the late 17th century.

The journey through loss and grief
In her brutally honest, ironically funny and widely read meditation on death, "You May Want to Marry My Husband," the late author and filmmaker Amy Krouse Rosenthal gave her husband Jason very public permission to move on and find happiness. A year after her death, Jason offers candid insights on the often excruciating process of moving through and with loss -- as well as some quiet wisdom for anyone else experiencing life-changing grief.

How to fix a broken heart
At some point in our lives, almost every one of us will have our heart broken. Imagine how different things would be if we paid more attention to this unique emotional pain. Psychologist Guy Winch reveals how recovering from heartbreak starts with a determination to fight our instincts to idealize and search for answers that aren't there -- and offers a toolkit on how to, eventually, move on. Our hearts might sometimes be broken, but we don't have to break with them.

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