Getting too little sleep doubles a young child's risk of being overweight and raises the chances of later anxiety and depression, researchers said on Monday.

Several studies published in the journal Archives of Pediatrics & Adolescent Medicine add heft to the notion that getting enough sleephas wide-ranging health benefits.

Previous studies have shown that older children and adults who get too little sleep are more likely to weigh too much. Researchers led by Dr. Elsie Taveras of Harvard Medical School demonstrated that this is also the case in very young kids.

In a study involving 915 children in Massachusetts, they found that those who slept less than 12 hours a day in the first two years of life were twice as likely to be overweight at age 3 than children who slept longer.

Very young children need more sleep and those in this study slept an average of 12.3 hours per day.

"There are consequences to children not sleeping well, even at this age," Taveras said in a telephone interview. "It's going to be important to help parents learn how to improve the quality of their children's sleep."

Television tended to make matters worse, with children who watched two or more hours daily by age 2 more likely to be overweight at age 3, the researchers said.

Taveras said getting enough sleep is becoming harder with televisions, computers and video games in kids' bedrooms.

The researchers said previous studies in adults and older children have shown that restricting sleep changes certain hormone levels, possibly stimulating hunger and weight gain.

EMOTIONAL FALLOUT

Another team of researchers led by Alice Gregory of the University of London examined the long-term emotional fallout from too little sleep in childhood. They gathered sleep data on 2,076 Dutch children ages 4 to 16, and then questioned them as adults years later about various emotional and behavioral symptoms.

The children who slept less than others reported more anxiety, depression and aggressive behavior as adults, the researchers said.

Researchers led by Valerie Sung of Royal Children's Hospital in Parkville, Australia found that children with attention-deficit hyperactivity disorder commonly had sleep problems.

Among 239 Australian children ages 5 to 18 years with ADHD in the study, 73 percent had sleep problems. Their most common problems were difficulty falling asleep, resisting going to bed and tiredness upon waking, Sung said.

Compared to other children with ADHD but no sleep problems, these children were more likely to have poorer quality of life and daily functioning, as well as poorer school attendance.

Sung offered advice to families of children with ADHD.

"If you are worried about your child's sleep, ask your doctor for help, and if help is not forthcoming, keep asking and seek help from a specialist sleep clinic at your closest children's hospital," Sung said by e-mail.

The latest research suggests that a baby's sleep problems can often be traced back to the parents, that too often, with the best of intentions, parents actually contribute to bad sleep habits. One common bedtime mistake is holding or rocking an infant. "The more parents interfere with the process of falling asleep at bedtime, the more likely that child is going to be dependent on the parent to fall asleep," Brown Medical School Dr. Judith Owens said. This is especially true at 3 o'clock in the morning. "When parents repeatedly respond to children or infants who are waking and crying, that's what the child learns to expect," Montefiore Medical Center Dr. Blanche Beneson said. Other common bedtime mistakes, the study found: Moving babies into the parent's bed in the middle of the night. Pediatricians recognize that some babies at bedtime are "stubborn". But they say if parents are consistent, and patient, babies will learn to fall asleep on their own

A study by the federal Consumer Product Safety Commission, released in 1999, concluded that at least 64 infants and toddlers die nationwide each year in adult beds. The study, covering 1990 through 1997, found 108 children smothered to death when a parent rolled over on them; another 128 were trapped between the mattress and a bed frame, headboard or footboard; and another 125 suffocated between the bed and the wall. The dangers are magnified when parents are obese or abuse drugs or alcohol. Despite the statistics and public awareness campaigns, some parents ignore the dangers of co-sleeping. In some cases, the decision not to have a crib is economic. In others, it is philosophical. Some parents prefer the closeness of sleeping with their babies, which they believe promotes bonding and breast-feeding. Co-sleeping is not confined to shelter families, nor are such deaths. But conditions of homelessness could foster co-sleeping - frequent moves, cramped living spaces and little money to buy cribs.

A Call for Training

Noting a recent spate of shelter deaths related to improper sleeping arrangements, Public Advocate Betsy Gotbaum has called for training for city and contract agency staff who have contact with infants.

"These types of death could be prevented through education," Gotbaum testified at a recent City Council hearing, where she proposed signs throughout homeless shelters urging parents to place their babies in cribs. The city's Administration for Children's Services said recently that it plans to distribute a video to shelters that, among other safety tips, warns against the dangers of co-sleeping.

Indeed, the parents of several shelter children who died after co-sleeping told investigators they were not aware of those dangers. Others acknowledged that they were aware but continued the practice anyway.

Partly because of cramped shelter rooms, some shelter families have actually been known to remove cribs from their units. The mother of Sade Faith Hathaway, a 2-month-old girl who died in a Red Cross-operated shelter in Manhattan in 2002, told workers she removed the crib from her room partly because she was afraid mice in the room would invade the crib. No cause was determined in Sade's death, but co-sleeping was listed as a possible factor in the medical examiner's report, along with dehydration and malnutrition.

Hard to Enforce

The non-profit organization HELP USA, which operates seven city shelters, has for the past decade required families with babies to use cribs, according to HELP USA official Fred Shack.

But Shack said enforcing that rule can sometimes be difficult when families are in the privacy of their own shelter units.

"We've had a number of situations in our facilities where children have rolled off the bed," said Shack, the organization's senior vice president of client services.

You may literally have to add it to your to-do list, but scheduling a good night's sleep could be one of the smartest health priorities you set. It's not just daytime drowsiness you risk when shortchanging yourself on your seven to eight hours. Possible health consequences of getting too little or poor sleep can involve the cardiovascular, endocrine, immune, and nervous systems. In addition to letting life get in the way of good sleep, between 50 and 70 million Americans suffer from a chronic sleep disorder—insomnia or sleep apnea, say—that affects daily functioning and impinges on health.

Consider the research:

1) Less may mean more. For people who sleep under seven hours a night, the fewer zzzz's they get, the more obese they tend to be, according to a 2006 Institute of Medicine report. This may relate to the discovery that insufficient sleep appears to tip hunger hormones out of whack. Leptin, which suppresses appetite, is lowered; ghrelin, which stimulates appetite, gets a boost.

2) You're more apt to make bad food choices. A study published this week in the Journal of Clinical Sleep Medicine found that people with obstructive sleep apnea or other severely disordered breathing while asleep ate a diet higher in cholesterol, protein, total fat, and total saturated fat. Women were especially affected.

3) Diabetes and impaired glucose tolerance, its precursor, may become more likely. A 2005 study published in the Archives of Internal Medicine found that people getting five or fewer hours of sleep each night were 2.5 times more likely to be diabetic, while those with six hours or fewer were 1.7 times more likely.

4) The ticker is put at risk. A 2003 study found that heart attacks were 45 percent more likely in women who slept for five or fewer hours per night than in those who got more.

5) Blood pressure may increase. Obstructive sleep apnea, for example, has been associated with chronically elevated daytime blood pressure, and the more severe the disorder, the more significant the hypertension, suggests the 2006 IOM report. Obesity plays a role in both disorders, so losing weight can ease associated health risks.

6) Auto accidents rise. As stated in a 2007 report in the New England Journal of Medicine, nearly 20 percent of serious car crash injuries involve a sleepy driver—and that's independent of alcohol use.

7) Balance is off. Older folks who have trouble getting to sleep, who wake up at night, or are drowsy during the day could be 2 to 4.5 times more likely to sustain a fall, found a 2007 study in the Journal of Gerontology.

8) You may be more prone to depression. Adults who chronically operate on fumes report more mental distress, depression, and alcohol use. Adolescents suffer, too: One survey of high school students found similarly high rates of these issues. Middle schoolers, too, report more symptoms of depression and lower self-esteem.

9) Kids may suffer more behavior problems. Research from an April issue of the Archives of Pediatric and Adolescent Medicine found that children who are plagued by insomnia, short duration of sleeping, or disordered breathing with obesity, for example, are more likely to have behavioral issues like attention deficit hyperactivity disorder.

10) Death's doorstep may be nearer. Those who get five hours or less per night have approximately 15 percent greater risk of dying—regardless of the cause—according to three large population-based studies published in the journals Sleep and the Archives of General Psychiatry.