Light Treatment for Seasonal Depression: How It Works and When to Try

When the days grow shorter and the sun seems to disappear, many people notice their mood sinking. For some, this seasonal shift brings on more than just the “winter blues.” It can trigger seasonal affective disorder (SAD), a type of depression linked to lack of sunlight. One of the most widely recommended treatments for SAD is light therapy, which is a safe and simple way to bring some “sunlight” back into your day. But how does it actually work, and how do you know when to try it?

TL;DR

• Light therapy uses a bright light box to mimic sunlight and treat seasonal affective disorder (SAD).

• It works by resetting your body’s clock, boosting mood chemicals, and improving sleep.

• Best used daily in the morning for 20–30 minutes during autumn and winter.

• Side effects are usually mild, like eye strain or headaches, but it’s safe for most people.

• Combining light therapy with therapy, exercise, and support from Meela enhances the effectiveness of recovery.

What Is Light Therapy?

Light therapy, also called phototherapy, involves sitting near a special light box that mimics natural outdoor light. Unlike regular lamps, these devices emit bright, white light at an intensity of around 10,000 lux, which is much stronger than typical indoor lighting. The goal is to replace the natural sunlight you miss during darker months.

This treatment isn’t about tanning or UV exposure. In fact, most light boxes filter out harmful UV rays. Instead, they help reset your body’s internal clock (circadian rhythm) and boost chemicals in the brain that affect mood, like serotonin and melatonin.

How Does It Work?

When you’re exposed to light in the morning, your brain gets a signal: It’s time to wake up, feel alert, and get moving. Without enough light, especially in winter, that signal weakens, leaving you groggy, sad, or unmotivated.

Light therapy strengthens this signal. By sitting near a light box for 20–30 minutes each day, usually in the morning, your brain gets the “sunlight” it needs to regulate sleep patterns, boost energy, and stabilize mood.

Think of it as giving your body a natural wake-up call when the sun can’t do its job.

When Should You Try Light Therapy?

Light therapy is most often recommended if you:

• Experience depressive symptoms mainly in autumn and winter.

• Notice your mood improves when you spend time outdoors in daylight.

• Have been diagnosed with seasonal affective disorder (SAD).

For many people, starting light therapy in early autumn—before symptoms become severe—helps prevent seasonal depression from taking hold.

How to Use Light Therapy Safely

Light therapy is simple, but it works best when used consistently and safely. Experts usually recommend:

• Timing it right: Use it in the morning to avoid sleep problems.

• Sitting at the right distance: Place the light box about 16–24 inches away, angled slightly so you’re not staring directly at it.

• Staying consistent: Daily sessions work best, especially during the darker months.

It’s also important to check with a doctor before starting, especially if you have eye conditions, bipolar disorder, or take medications that increase light sensitivity.

Benefits of Light Therapy

Many people report feeling better within a week of starting light treatment, though for some it may take longer. Benefits often include:

• Improved mood and energy.

• Better focus and productivity.

• Healthier sleep patterns.

• Reduced feelings of hopelessness or sadness during winter.

Are There Any Side Effects?

Light therapy is generally safe, but some people may experience mild side effects at first, such as headaches, eye strain, or mild nausea. These often fade as your body adjusts. Choosing the right time of day and not sitting too close can reduce these effects.

Other Ways to Support Seasonal Depression

While light therapy is effective, it’s often more helpful when combined with other supports, such as:

• Counseling or therapy (like CBT for SAD).

• Exercise, especially outdoors in daylight.

• Healthy routines around sleep and nutrition.

• Medication, if recommended by a healthcare provider.

At Meela, we believe in a whole-person approach to mental health. Light therapy can be one tool in your toolbox, but real healing often comes from combining it with therapy and ongoing support. Our platform connects you with licensed therapists who understand the challenges of seasonal depression and can guide you through practical coping strategies, whether that’s managing sleep patterns or reducing stress.