When we lose a beloved superstar like Robin Williams to an apparent suicide and learn he had been battling severe depression before his death, it's natural to think about our own loved ones.
We might look around at our adult family members and friends who are suffering and try to get them the help they need, but what we might not see is children and adolescents can get depressed and anxious, too.
And it's more common than we probably realize.
On any given day, according to studies, it is estimated that about 2% of elementary-school-age children and about 8% of adolescents suffer from a major depression, and 1 in 5 teens has had a history of depression at some time, according to the National Alliance on Mental Illness.
But how does a parent differentiate between what might be considered normal irritability and moodiness, especially during those teenage years, and signs that something more serious is afoot?
"I think you should start worrying ... anytime there's enough of a change when you go, 'Oh my God they don't seem like themselves,'" said Dr. Charles Raison, a professor of psychiatry at the University of Arizona College of Medicine.
Raison says the timeline is key; parents should perk up if for two to three weeks their children are "unremittingly down," feeling hopeless and negative, if they start to withdraw from friends and activities, and if they experience dramatic changes in sleep.
Depressed teens might have difficulty falling asleep, not be able to fall back asleep after they wake up in the middle of the night or wake up very early in the morning. At the other end of the spectrum, they could be getting excessive amounts of sleep, sometimes sleeping 12 hours or more, psychiatrists say.
For younger kids, detecting depression gets "more complicated" for parents, Raison said, because children below the age of puberty don't necessarily show the same signs of depression as teens and adults.
"The younger the kid, the more scrambled the symptoms can be," he said. "They're easily upset. They cry more. They're scared to sleep alone at night. They become irritable. They act out more."
In younger children, parents aren't likely to see the "classic depressive pattern," Raison said. "But you're still looking for that same larger idea, which is if your kid shows a real maladaptive change in their emotions (and) their behavior, the light needs to go off in your head because something isn't right."
Melissa Atkins Wardy, a mom of two in Janesville, Wisconsin, and author of "Redefining Girly," said she was never aware that children as young as her daughter Amelia, who is now 8, could develop anxiety outside of a traumatic experience.
But halfway through first grade, Amelia said she didn't want to go to school, and reluctance to go to school "morphed into tears and nausea every day and then tears and worry at bedtime, too," said Atkins Wardy, founder and CEO of the company, Pigtail Pals & Ballcap Buddies, which creates empowering T-shirts for girls and boys.