Most of us know that sleepless nights can unhinge your emotions. Now scientists have a better idea of why this happens. They’ve shown that lack of sleep strongly activates the brain’s emotional centers and weakens the brain circuits that keep your emotions under control.

Scientists know that lack of sleep can interfere with your health in many ways. It can disrupt your learning and memory and your ability to fight disease. But they’ve understood much less about how sleep and emotions are connected in the brain.

NIH-funded researchers scanned the brains of 26 healthy adults while they looked at 100 images. At first, the images were neutral—like a chair or a bowl of fruit. Later, they became more unpleasant and disturbing—like a dirty toilet bowl, a burn victim or mutilated bodies.

Some participants had a good night’s sleep before the brain scan. Others had been kept awake for about 35 hours straight—about how long you’d be up if you stayed awake all night and into the next afternoon without naps.

For everyone, the disturbing pictures led to greater activation of a primitive brain region that triggers strong emotions. But the activation was 60% more intense in the people who were sleep deprived and spread over a larger area.

Lack of sleep had another effect on the brain’s circuitry. In the sleep-deprived group, the brain’s emotion center seemed to be more strongly connected to a primitive, impulsive brain region and less connected to a region that normally keeps emotions and behaviors in check.

The researchers say their study demonstrates the dangers of not sleeping enough. Their findings suggest that sleep restores the control of our emotional brain circuits and helps us face the next day’s challenges and social interactions.

Soaring obesity rates are making type 2 diabetes, a disease that used to be seen mostly in adults over age 45, more common among young people. The National Diabetes Education Program (NDEP) has created new resources to help teens diagnosed with diabetes, along with their parents, manage their disease.

Diabetes is a group of diseases marked by high levels of glucose in the blood. Persistent high levels can lead to blindness, kidney failure, amputations, heart disease and stroke. Type 2 diabetes, formerly called adult-onset diabetes, is the most common form. People can develop it at any age. Being overweight and inactive increase your risk.

NDEP’s new Tips for Teens with Diabetes series encourages youth to take steps to manage their disease for a long, healthy life. It includes topics such as What is Diabetes?, Make Healthy Food Choices and Dealing with the Ups and Downs of Diabetes. NDEP also created a tip sheet for teens at risk for type 2 diabetes, called Lower Your Risk for Type 2 Diabetes.

There’s also an interactive online quiz for teens with diabetes. All these are available at no charge.