What is the recommended treatment for seasonal affective disorder?

Treatment of Seasonal Affective Disorder

Bright light therapy at 10,000 lux for 30 minutes each morning is the recommended first-line treatment for seasonal affective disorder, with bupropion XL as an FDA-approved pharmacologic alternative for prevention of seasonal depressive episodes. 1, 2

First-Line Treatment: Bright Light Therapy

Light therapy should be administered at 10,000 lux for 30 minutes daily in the morning, which has proven superior to evening administration. 1 An alternative regimen of 2,500 lux for 2 hours daily can be used if the higher intensity is not tolerated. 1

Implementation Details

• Morning timing is critical - morning light therapy demonstrates superior efficacy compared to evening treatment and should be the standard approach. 1
• Treatment typically begins in autumn, prior to symptom onset, and continues through the winter season with discontinuation in early spring. 2
• Response rates reach approximately 80% in selected patient populations, with atypical depressive symptoms predicting the most favorable outcomes. 3
• Clinical response often emerges within the first week of treatment. 4

Safety Profile and Monitoring

Monitor closely for emergent hypomania in the first few days of treatment, as this represents the most significant risk with light therapy. 1 The relative risk of hypomania is 4.91 compared to controls, though this primarily occurs in patients with underlying bipolar disorder. 5

Common side effects are generally mild and self-limiting: 1, 6

• Eyestrain, nausea, and agitation (most resolve spontaneously)
• Jumpiness/jitteriness (8.8% emergence rate)
• Headache (8.4% emergence rate)
• Treatment-emergent headaches commonly remit, but light therapy can trigger migraines in approximately one-third of susceptible individuals 5

Patients with eye disease or those taking photosensitizing medications require periodic ophthalmologic and dermatologic monitoring. 1 Reassuringly, extensive ophthalmologic examinations showed no changes in SAD patients without preexisting conditions after up to 6 years of daily fall/winter use. 5

FDA-Approved Pharmacologic Treatment: Bupropion XL

Bupropion hydrochloride extended-release (XL) is FDA-approved specifically for prevention of seasonal major depressive episodes in patients with SAD. 2

Dosing Protocol

• Start at 150 mg once daily in the morning
• After 7 days, increase to the target dose of 300 mg once daily in the morning 2
• Initiate in autumn, prior to onset of depressive symptoms 2
• Continue through winter season 2
• Taper before discontinuation: decrease from 300 mg to 150 mg once daily before stopping in early spring 2

Key Prescribing Considerations

• Doses above 300 mg were not assessed in SAD trials 2
• Increase dose gradually to minimize seizure risk 2
• Tablets must be swallowed whole (not crushed, divided, or chewed) 2
• Can be taken with or without food 2
• Bupropion appears to have the strongest evidence supporting long-term preventive use 7

Alternative Pharmacologic Options

SSRIs represent effective alternatives, with fluoxetine and sertraline showing efficacy in randomized controlled trials. 4, 3

• Fluoxetine demonstrated comparable clinical response rates (67%) and remission rates (54%) to light therapy in head-to-head comparison 4
• However, fluoxetine was associated with greater treatment-emergent adverse events including agitation, sleep disturbance, and palpitations 4
• Moclobemide (a reversible MAOI-A inhibitor) also showed promise in double-blind, placebo-controlled trials 3

Expanded Application Beyond Traditional SAD

Recent VA/DoD guidelines recommend bright light therapy for mild to moderate major depressive disorder regardless of seasonal pattern, expanding its potential application beyond traditional SAD. 5, 1 This recommendation is based on systematic review evidence of 1,200 patients demonstrating benefits even in patients without seasonal elements. 5

Adjunctive Interventions

Lifestyle modifications should complement primary treatment: 7

• Increase physical exercise
• Maximize exposure to natural outdoor light during daylight hours

Treatment Algorithm

1. Initiate bright light therapy (10,000 lux × 30 minutes each morning) in autumn before symptom onset
2. Monitor for hypomania in first few days, particularly in patients with any history of bipolar features
3. If inadequate response after 2 weeks or intolerable side effects, consider:
   • Add bupropion XL (150 mg × 7 days, then 300 mg daily), OR
   • Switch to bupropion XL monotherapy for prevention
4. For patients preferring pharmacotherapy from the outset, bupropion XL is the FDA-approved option with strongest long-term evidence 2, 7
5. Continue treatment through winter; taper and discontinue in early spring 2

Critical Pitfalls to Avoid

• Do not use evening light therapy - morning administration is superior 1
• Do not abruptly discontinue bupropion 300 mg - taper to 150 mg first 2
• Do not overlook bipolar screening - hypomania emergence is the most significant risk with light therapy 1
• Do not prescribe light therapy without counseling about photosensitizing medications and eye disease - these require monitoring 1