SAD: Understanding Seasonal Affective Disorder

First published in 2017
Updated March 2026

During the colder months, it sometimes feels like winter will be here forever and spring will never arrive. The gray skies can give us a case of winter blues making us feel sluggish, sad, tired and unmotivated. For some children, these seasonal changes may be linked to a type of depression called seasonal affective disorder (SAD).

SAD is a form of depression that follows a seasonal pattern. Symptoms most often begin in the fall and continue through the winter months, when daylight hours are shorter. Less commonly, some children experience symptoms during the spring or summer.

What Causes Seasonal Affective Disorder?

The exact cause of SAD is not fully understood, but several factors may contribute:

• Reduced sunlight exposure (morning light) may disrupt the body’s internal clock (circadian rhythm).
• Changes in brain chemicals, including lower serotonin levels, can affect mood.
• Changes in melatonin levels may impact sleep patterns, energy and emotional regulation.
• Symptoms often become more noticeable as the season progresses and daylight continues to decrease.

Common Signs of SAD

A child with SAD may:

• Have low energy or feel tired most of the time
• Daytime sleepiness
• Difficulty waking in the morning
• Sleep more than usual or have changes in sleep patterns
• Lose interest in activities they previously enjoyed
• Withdraw from friends or social activities
• Experience changes in appetite, especially increased cravings (often carbohydrates) or overeating
• Feel sad, hopeless or worthless
• Become more irritable or have increased emotional outbursts
• Have difficulty concentrating or keeping up with schoolwork
• Talk about death or express thoughts of self-harm or suicide

Any mention of self-harm or suicide should be taken seriously and addressed immediately with a medical or mental health professional.

If you or your child need immediate help due to having suicidal thoughts, call or text the 988 Suicide & Crisis Lifeline at 988. If there is an immediate safety concern, call 911 or go the nearest emergency room.

How Is SAD Treated?

If seasonal depression is suspected, start with a supportive conversation. Children may not always recognize or express what they are feeling, so gentle questions and reassurance are important.

Treatment options may include:

• Light therapy, which uses a special light box (e.g., 10,000 lux light box) to mimic natural sunlight
• Natural light for 20-30 minutes within the first hour of waking,
• Psychotherapy, such as cognitive behavioral therapy, to build coping skills
• Medication, when recommended by a qualified health care provider
• Healthy routines, including regular sleep, physical activity and time outdoors when possible

A pediatrician or mental health professional can help determine the most appropriate treatment based on a child’s symptoms and needs.

When to Talk With a Doctor

It can be difficult to tell the difference between typical winter mood changes and SAD. Consider contacting a pediatrician or mental health provider if:

• Mood, energy or behavior changes last for several days or weeks
• Symptoms interfere with school, relationships or daily activities
• Usual activities that normally improve mood are no longer helping
• There are concerns about safety, self-harm or suicidal thoughts

While waiting for an appointment, spend extra time connecting with your child, maintain predictable routines and provide additional support for daily responsibilities.