(NewsNation) — As the days get shorter, darker and colder, you may find yourself feeling not quite yourself. Every year, millions struggle with “winter blues” that make the transition into the colder months difficult.

Seasonal Affective Disorder, aptly shortened to SAD, is a type of depression related to the change in seasons. For most, symptoms start in the fall and continue through winter, draining those affected of energy and making them feel moody and off

Experts say if you experience significant changes in behavior and mood when the seasons change, you may be experiencing SAD

According to the Mayo Clinic, symptoms of SAD include:

• Feeling listless, sad or down most of the day
• Losing interest in activities you once enjoyed
• Having low energy and feeling sluggish
• Sleeping too much
• Craving carbohydrates, overeating and having weight gain
• Having difficulty concentrating
• Feeling hopeless or worthless
• Having suicidal thoughts

There are no clear causes of SAD, but less sunlight and shorter days have been linked with chemical imbalances in the brain, according to John Hopkins Medicine.

While less common, some people experience SAD in an opposite pattern, having symptoms that begin in the spring or summer.

Summer-onset SAD can come with symptoms like insomnia, poor appetite, weight loss and increased irritability, according to the Mayo Clinic.

The National Institute of Mental Health warns that winter-pattern SAD should not be confused with “holiday blues” and to talk to a doctor or mental health specialist if you are experiencing symptoms

Treatments for SAD typically fall into four main categories: light therapy, psychotherapy, antidepressant medication and vitamin D. These can be used alone or in combination.

Increasing your exposure to sunlight and spending time outside can help relieve symptoms, but if it is not possible, using a special light for a specific amount of time may also help, according to the NIMH.

Johns Hopkins Medicine says there are also things you can do for yourself to help relieve SAD symptoms:

• Don’t take on too much and prioritize tasks
• Try to be around people and confide in someone
• Do an activity you typically enjoy
• Eat healthy, well-balanced meals
• Stay away from drugs and alcohol. These can make depression worse
• Delay making big decisions