Light Therapy 101: Beating the October Shift

For some people, the transition into fall brings more than cooler temperatures and shorter days. As daylight decreases in October, changes in light exposure can affect the body’s circadian rhythm, sleep-wake cycle, energy level, and mood. For individuals who are already vulnerable to depression or anxiety, these changes may become more noticeable.

Seasonal changes in mood do not automatically mean someone has Seasonal Affective Disorder (SAD). SAD is a form of depression with a recurrent seasonal pattern, most commonly beginning in the fall or winter. Symptoms can include depressed mood, decreased interest in activities, fatigue, changes in sleep or appetite, difficulty concentrating, and social withdrawal.

If you notice that these symptoms consistently emerge or worsen as the days become shorter, it can be helpful to look at the pattern rather than dismissing it as simply feeling “off” during the winter.

Here are three clinically informed strategies that may help support your mental health during the October shift.

1. Increase Your Exposure to Morning Light

Light exposure is one of the strongest environmental cues for regulating the circadian rhythm. Morning light helps regulate the timing of the sleep-wake cycle and influences biological processes associated with alertness and sleep.

When daylight hours decrease, many people naturally receive less morning and daytime light. This can be particularly relevant for individuals who spend most of their day indoors.

Whenever possible, incorporate natural light into your morning routine. This could include taking a walk outside, sitting near a window, or spending time outdoors before beginning your workday.

For individuals experiencing clinically significant seasonal depressive symptoms, bright light therapy may be recommended as part of treatment. Bright light therapy generally involves using a specialized light box for a specific amount of time, often in the morning.

It is important to understand that light therapy is a clinical intervention rather than simply using a brighter household lamp. Appropriate intensity, timing, duration, and positioning matter. Individuals should discuss light therapy with their healthcare provider, particularly if they have certain medical conditions, take medications that increase sensitivity to light, or have a history of mood symptoms that could be affected by changes in sleep or circadian rhythm.

2. Pay Attention to Changes in Sleep

Changes in daylight can influence sleep, and disrupted sleep can subsequently affect emotional regulation. This relationship can become cyclical: changes in mood may affect sleep, while inadequate or excessive sleep can make mood symptoms more difficult to manage.

As fall progresses, pay attention to whether you are sleeping substantially more or less than usual, having difficulty getting out of bed, experiencing persistent daytime fatigue, or struggling to maintain your usual routine.

Maintaining a relatively consistent sleep schedule can provide your body with predictable cues. Consider keeping your wake time consistent, getting exposure to light earlier in the day, and establishing a regular wind-down routine at night.

If you notice significant changes in sleep occurring alongside persistent changes in mood, motivation, or functioning, it may be useful to discuss those symptoms with a mental health or medical professional.

3. Use Behavioral Activation Instead of Waiting for Motivation

One of the clinical patterns associated with depression is behavioral withdrawal. When someone feels fatigued, overwhelmed, or depressed, the natural response may be to stay home, cancel plans, spend more time in bed, or stop participating in activities they previously enjoyed.

While rest is important, prolonged withdrawal can also reinforce depressive symptoms.

Behavioral activation, an evidence-based component of depression treatment, focuses on intentionally increasing engagement in meaningful and reinforcing activities. The goal is not to force yourself to be productive or pretend that you feel better than you do. Instead, it involves recognizing that behavior and mood influence one another.

As the days become shorter, consider intentionally maintaining activities that support your functioning and emotional health.

This might include:

• Maintaining regular physical activity
• Spending time outdoors during daylight hours
• Staying connected with supportive people
• Continuing hobbies and meaningful activities
• Maintaining work, school, and household routines
• Scheduling activities rather than waiting until you “feel like it”
• Making space for rest without completely withdrawing

A common misconception is that motivation needs to come first. In depression, the opposite can sometimes be true. Taking a small, manageable action can create an opportunity for improved mood, connection, or a sense of accomplishment.

Monitor the Pattern, Not Just the Individual Day

One difficult day does not necessarily indicate a seasonal mood disorder. Clinically, it is more useful to look at patterns over time.

Ask yourself: Do I notice this happening around the same time each year? Are my symptoms affecting my relationships, work, school, sleep, or daily functioning? Am I withdrawing from activities I typically value?

Tracking these changes can help you identify whether there is a recurring seasonal pattern and provide useful information to discuss with a mental health professional.

If you are experiencing persistent depression, significant anxiety, changes in sleep or appetite, loss of interest in activities, or difficulty functioning, you do not need to wait until symptoms become severe before seeking support.

When to Reach Out for Professional Support

Seasonal changes can affect mental health, but significant or persistent symptoms deserve attention. Therapy can help individuals identify patterns, address unhelpful thinking and behavioral patterns, improve coping skills, and develop strategies for managing symptoms.

The goal is not to eliminate every change in mood that comes with the seasons. Instead, it is to recognize when seasonal changes are beginning to affect your functioning and respond early.

This October, pay attention to your light exposure, sleep, activity level, and mood. These areas can provide important information about how the seasonal transition is affecting you. If you notice a consistent pattern of worsening symptoms, consider reaching out for professional support rather than trying to manage it on your own.