Major Research Findings

Bright light therapy has become a widely accepted treatment for seasonal affective disorder (SAD), but studies on its adverse effects are limited. One study 2 examined the frequency of adverse effects of bright light therapy for SAD. Another study analyzed side effects focusing on a narrow set of symptoms based on clinical observation (e.g. headache, eyestrain, nausea, insomnia, and hyperactivity). This study expanded the scope to include 88 physical and subjective symptoms that could emerge, disappear, or remain unchanged relative to baseline, thus reducing bias in the assessment of presumed side effects.

Reasons for Side Effects

The exact reasons for side effects from bright light therapy are still not fully understood. However, the study suggests that these side effects may be related to changes in the visual, nervous, and endocrine systems induced by light therapy.

Common Side Effects

Headache

Study identified headache as a common side effect of bright light therapy.

Eyestrain

Study identified eyestrain as a common side effect of bright light therapy.

Nausea

Study identified nausea as a common side effect of bright light therapy.

Insomnia

Study identified insomnia as a common side effect of bright light therapy.

Hyperactivity

Study identified hyperactivity as a common side effect of bright light therapy.

Side Effects Management

Headache Management

If you experience headaches, consider lowering the intensity of the light therapy or increasing your break times. Over-the-counter pain relievers may also be helpful.

Eyestrain Management

If you experience eyestrain, consider shortening the duration of light therapy or increasing your break times. Eye drops or resting your eyes may also be effective.

Nausea Management

If you experience nausea, it is important to stop light therapy and seek medical advice.

Insomnia Management

If you experience insomnia, consider shifting the time of light therapy to the morning or reducing light levels at night. Sleep medication may also be helpful.

Hyperactivity Management

If you experience hyperactivity, consider shortening the duration of light therapy or increasing your break times. Exercise or relaxation techniques may also be effective.

Comparison of Studies

Commonalities of Studies

All three studies indicate that bright light therapy is an effective treatment for SAD. They also all point out that bright light therapy may have side effects.

Differences in Studies

Studies 2 and investigated side effects of bright light therapy, while study 1 examined the neuroendocrine response to 5-hydroxytryptophan in SAD patients and did not investigate side effects. Study investigated a wider range of 88 physical and subjective symptoms compared to study 2 which focused on a limited number of side effects.

Real-Life Application Precautions

While bright light therapy is an effective treatment option for SAD, it is important to be aware of the risk of side effects. If you experience any side effects, discontinue light therapy and consult with your doctor.

Limitations of Current Research

Current research on the side effects of bright light therapy is still lacking sufficient data. More research, especially on long-term side effects, is needed.

Future Research Directions

Future research needs to focus on long-term side effects of bright light therapy and methods to mitigate these side effects.

Conclusion

Bright light therapy is an effective treatment option for SAD, but it may cause side effects such as headaches, eyestrain, nausea, insomnia, and hyperactivity. If you experience any side effects, discontinue light therapy and consult with your doctor. More research on long-term side effects and methods to mitigate these side effects is needed.