A behavior health expert tells News 12 during this time of year, it's important to be aware of Seasonal Affective Disorder (SAD).

"Usually, it starts as the season is changing, as we're starting to move from summer to fall. A change in sunlight and a change in temperature. It may be when the time change happens," says Cara McNulty of CVS behavioral health and mental well-being.

The National Institute of Mental Health says the disorder, which is also a form of depression, can prompt a biochemical imbalance in the brain that creates an anxious, irritable and empty mood.

"It can happen to anyone. Your energy is different, you're just not as engaged or excited," says McNulty.

McNulty says to pay attention if SAD lasts a couple of weeks as opposed to several days and is not improving. Ways to combat the disorder include going outside, getting enough sleep, eating well and drinking water.

If SAD persists, people should speak to their primary care provider. They may recommend starting therapy or taking an anti-depressant.

McNulty says studies show 6% of the population experiences SAD.