J. Todd Arnedt, Ph.D.
Assistant Professor of Psychiatry and Neurology
Director, Behavioral Sleep Medicine Program
University of Michigan, Ann Arbor, MI
Other Names for Seasonal
Affective Disorder (SAD)
 Winter Depression
 Seasonal Depression
 Major Depression with a Seasonal Pattern
Characteristics of SAD
 Most commonly subtype of MDD, but can also apply to
Bipolar I and Bipolar II disorder (with Seasonal Pattern)
 Predictable onset (September-October) and offset
(March-April) with absence of symptoms in summer –
rarely can be recurrent summer depressive episodes
 Seasonal pattern evident for the last 2 years, without
nonseasonal depressive episodes
 Seasonal episodes must outnumber nonseasonal episodes
 Does not apply when pattern better explained by seasonal
psychosocial stressors (e.g., seasonal unemployment)
What are the symptoms of SAD?
 Typical symptoms of depression develop in fall or
early winter: low mood, anhedonia, poor
concentration, low energy, fatigue
 Atypical vegetative symptoms: increased sleep,
appetite, weight gain, carbohydrate craving,
leaden paralysis
 Irritability with more alcohol use
SAD Symptoms
http://www.medscape.org/viewarticle/508141
Clinical features of SAD
http://www.medscape.org/viewarticle/508141
How common is SAD?
 1-3 % prevalence
 10-20% of Americans
have some symptoms
 More common as we
get closer to the poles
 Rare within 30 degrees
of the equator
http://www.medscape.org/viewarticle/508141
SAD relationship with latitude
http://www.medscape.org/viewarticle/508141
Causes of SAD: Short photoperiod
http://www.medscape.org/viewarticle/508141
Causes of SAD: Biological clocks
Other possible causes
 Inappropriate phase angle rather than phase position
 Serotonin deficiency (5HT2C and 5HT7) supported by tryptophan
depletion studies and 5HT medications
 Possibly NE and DA deficiency BUT need more research
 Genetic factors both protective from (Icelandic emigrants) and
vulnerable to SAD (polymorphism in promoter region of 5-HT
transporter and 5-HT 2A receptor)
Treatment: Phototherapy
www.cet.org
SAD Treatment: Phototherapy
 Spectrum: 450 (blue) to 500 (blue/green) best to suppress
melatonin and induce phase shifts but no definitive studies
compared to broad-spectrum white light
 Intensity: 2,500 - 10,000 lux
 Timing: morning preferred although benefits have been
shown at other times of the day relative to dim light controls.
 Duration: 30-120 min recommended, depending on intensity
 Optimal response rates may be seen when administered 7.5 –
9.5 hours after melatonin onset.
 Contraindications: retinal disease, some photosensitizing
drugs, caution with h/o bipolar disorder
Minor side effects and precautions of
phototherapy
 Eye strain
 Headache
 Irritability
 Insomnia
 Rarely, hypomania or
mania
Horne-Östberg MorningnessEveningness Questionnaire (MEQ)
Sample Questions:
4. Assuming adequate environmental conditions, how easy
do you find getting up in the morning?
8. When you have no commitment the next day, at what
time do you go to bed compared to your usual bedtime?
9. Suppose that you can choose you own work hours.
Assume that you worked a FIVE hour day and that your
job was interesting and paid by results. Which FIVE
CONSECUTIVE HOURS would you select?
18. At what time of the day do you think that you reach your
“feeling best” peak?
Horne & Östberg. Int J Chronobiol 1976;4:97-110.
Horne-Östberg MEQ: Scoring
Interpretation
Evening type
20
Neither type
40
Type
Definitely Evening
Moderately Evening
Neither
Moderately Morning
Definitely Morning
60
Morning type
80
Score
16-30
31-41
42-58
59-69
70-86
Timing of Light Therapy
MEQ Score
Start Time
MEQ Score
Start Time
16-18
0845
54-57
0615
19-22
0830
58-61
0600
23-26
0815
62-65
0545
27-30
0800
66-68
0530
31-34
0745
69-72
0515
35-38
0730
73-76
0500
39-41
0715
77-80
0445
42-45
0700
81-84
0430
46-49
0645
85-86
0415
50-53
0630
10,000 lux, 30-minute session, about 8.5 hours
after melatonin onset
Terman & Terman, In Principles and Practice of Sleep Medicine, 4th Ed, 1424-42, 2005
Phototherapy treatment and prevention
of SAD
 Start using light box in October
 Go outside!
 Sit by windows when possible
 Regular sleep pattern, especially rise time
 Limit alcohol
 Ask your family or friends to help monitor severity
of your symptoms
Antidepressant medication Rx for SAD
 Sertraline [Zoloft] (N = 187) and fluoxetine
[Prozac] (N = 68) both shown effective
 Other SSRI (citalopram [Celexa]) and SNRI
(duloxetine [Cymbalta]) medications have been
tested in open label studies
 Bupropion XL [Wellbutrin] (N = 1042) shown
effective and approved by F.D.A. in 2006
 3 placebo-controlled clinical trials
 150-mg once daily in the morning and titrated to 300
mg/day (target dose) after 1 week if tolerated.
Acute treatment of SAD
 96 patients with DSM-IV
SAD studied over 3
consecutive winters
 8 weeks of double-blind
treatment
 2 treatment conditions:
 10,000-lux 30-min
morning light plus
placebo
 100-lux plus fluoxetine
20 mg/day
Lam RW. Am J Psychiatry 2006;163:805-12.
Preventive treatment of SAD
1042 SAD patients received bupropion XL 150-300 mg or placebo from
fall (Sept to Nov) until spring (March) in 3 prevention RCTs
Modell JG. Biol Psychiatry 2005;58:658-67.
Other potential treatments
 Naturalistic dawn simulation
 High-density negative air ionization
 Physical exercise
 Cognitive-behavioral therapy (CBT)
 Treatments can be combined for maximum
benefit (e.g., light therapy with antidepressants,
light therapy with CBT)
Major Depressive Disorder (MDD) and SAD
 MDD often gets worse in winter
 This is NOT just SAD
 MDD should be treated with medications and
Cognitive Behavioral Therapy or Interpersonal
Psychotherapy.
 Phototherapy may be used to help seasonal flare-ups
but light therapy should not replace other needed
treatments
 Consult your clinician
When should light therapy be used?
 Depression is mild
 Good adherence, able to make time commitment
 Medications contraindicated (e.g., pregnancy, breast
feeding)
 Cost considerations: Greater initial cost and insurance
coverage is variable.
When should medication be used?
 Depression is severe or suicidality is present
 Depression episodes during summer, don’t end in
spring (can supplement with light therapy)
 No response to or relative contraindications to light
therapy (e.g., retinal disease, photosensitizing drug)
 Cost considerations
Conclusions
 SAD is a serious psychiatric disorder with significant
morbidity and reduced quality of life for patients.
 Causes of SAD are still under investigation but circadian
rhythm, neurotransmitter, and genetic factors all likely
contribute
 Safe and effective medication and non-medication
treatments for SAD exist and can be combined for
maximum benefit. Some patients may benefit from
preventive treatment.
Resources
 Rosenthal NE. Winter Blues: Everything You Need to Know
to Beat Seasonal Affective Disorder, 2005
 Center for Environmental Therapeutics: www.cet.org
 Society for Light Treatment and Biological Rhythms:
www.sltbr.org
 Seasonal Affective Disorder Association: www.sada.org.uk