Parents do a lot of guessing on what could be troubling a fussy baby.

If he's crying, he may be hungry or tired. But could he be depressed?

Any parent knows that young children have to be protected from a mind-boggling number of risks, but many will be surprised to learn that infant depression could be one of them.

"Babies can be depressed," said Dr. Jess Shatkin, director of education and training at New York University's Child Study Center. "It's not a terribly common phenomenon. We think maybe one in 40 or so -- but it can certainly happen."

Although it's not very common, there are two telltale signs of baby depression, experts say.

First, depressed babies do not exhibit a lot of emotion. Second, depressed babies may have trouble eating or sleeping, and may be irritable.

In Britain, a 4-year-old girl recently made news when her doctor said her depression was so serious, she may need antidepressants to treat it.

Stateside, new research on the brain has thrust infant mental health into the spotlight, but a young child's life seems so easy. How does a baby get the blues?

"Children can be raised in all sorts of environments, very loving, nurturing and focused environments and environments that can be neglectful for the child or even damaging," Shatkin said.

Research has long confirmed that genetics and brain chemistry play critical roles in the emotional health of babies and young children, but doctors stress that the mental health of the parent or caregiver also has a critical impact.

"The risk of a child being depressed or having a behavior disorder or an anxiety disorder, if that child has a depressed parent, is about three times that in the general population," Shatkin said.

No matter what the cause, depression in babies can be treated and because young children are often highly resilient, intervening early can dramatically improve the emotional life of the entire family.

"It's not like you're going to put the 10-month-old on the couch and do psychotherapy with them, but you work with the family caregivers to try to get them to understand what's going on with their child and to work with them on becoming more responsive and better parents," Shatkin said.

What You Can Do

If you suspect your baby is depressed, see your pediatrician.

Parents should think of their child's mental and emotional health as critical as physical health.

For more information on infant mental health, please visit www.zerotothree.org.

Popping a bottle of champagne during a New Year's Eve bash may be a tradition, but drinking in excess while ringing in 2017 can be especially dangerous in cold weather.

Liquor can help you "feel" warmer as blood vessels on the skin's surface open, according to the University of Rochester Medical Center. However, that "feeling" of warmth does not mean your body temperature will be affected. You will still be just as likely to get frostbite or hypothermia.

The U.S. Centers for Disease Control and Prevention advises people to abstain from caffeinated and alcoholic beverages while in the cold since "they cause your body to lose heat more rapidly."

Dr. Noah Rosen, director of Northwell Health's Headache Center in Great Neck, New York, said sipping a stiff whiskey drink may sound like a good idea to counteract cold temperatures, but it will only raise your blood alcohol level.

"It's a sensation of warmth but it's not actually increasing core body temperature," Rosen told ABC News.

For those with heart conditions, drinking in cold weather can be hazardous since people may be under additional strain from the cold and not realize it, the American Heart Association warns.

"Alcohol may increase a person’s sensation of warmth and may cause them to underestimate the extra strain their body is under in the cold," the AHA explained on its website.