II. Definitions
- Seasonal Affective Disorder
- Depressed mood that occurs within a specific time window of the year (typically fall-winter)
III. Epidemiology
- Annual Incidence in United States: <5%
- Lifetime Prevalence: 0.5 to 2.4%
- Of those with Major Depression, 10-20% have a seasonal pattern to their Major Depression
- Peak Incidence
- Fall and winter (October to February)
- Variation occurring Spring-Summer is less common
- Gender
- Female more than Male by factor of 4
- Age
- Uncommon under age 15 years
- Uncommon in elderly
-
Family History
- Identical twin studies suggest a genetic predisposition
IV. Symptoms
- See Major Depression Diagnosis Criteria
V. Diagnosis: DSM V Criteria (all must be present)- Variant of Major Depression
- Regular temporal relationship of Major Depression onset
- Occurs at the same time every year
- Usually occurs in fall or winter
- Unrelated to seasonal life stressors
- Full remission occurs at a specific time of year
- Two Seasonal Major Depression episodes in last 2 years
- No Non-seasonal episodes of Major Depression in 2 years
- Seasonal Depression episodes outnumber non-seasonal
VI. Diagnosis: Instruments
- Standard depression tools may be used to diagnosis presence and severity of Major Depression
- Patient Health Questionaire 9 (PHQ-9)
- Zung Self-Rating Depression Scale
- Beck Depression Inventory
- Hamilton Depression Scale
- Avoid SPAQ for clinical diagnosis (intended for research settings, and variable efficacy in practice)
VII. Associated conditions
VIII. Management
-
Light Therapy (preferred therapy)
- Timing
- Start therapy in early fall and continue until spring
- Light exposure early in day
- Synchronizes with circadian rhythm
- Terman (2001) Arch Gen Psychiatry 58:69-75 [PubMed]
- Dose and Duration (white fluorescent light with UV wavelengths filtered out)
- Exposure to 10,000 lux for 30 minutes per morning (Preferred) or
- Exposure to 2500 lux for 2 hours per morning (Dawn simulation at end of sleep cycle and early in day)
- Contrast with mid-day sun intensity (50,000 to 100,000 lux)
- Technique
- Keep eyes open during this time
- Do not need to stare at the light
- Timing
- Cognitive behavior therapy
- Cognitive Behavioral Therapy is associated with significant improvements in the short and longterm
- Rohan (2009) Behav Ther 40(3): 225-238 [PubMed]
- Rohan (2015) Am J Psychiatry 172(9):862-9 [PubMed]
- Rohan (2016) Am J Psychiatry 173(3): 244-51 [PubMed]
- Pharmacotherapy
- Indications
- High Suicide Risk
- Significant functional Impairment
- Recurrent moderate to severe Major Depression
- Patient preference
- Failure to respond to Light Therapy, Psychotherapy
- Agents
- Selective Serotonin Reuptake Inhibitor (SSRI)
- Fluoxetine (Prozac) and Sertraline (Zoloft) have been most studied (limited evidence)
- Thaler (2011) Cochrane Database Syst Rev (12):CD008591 [PubMed]
- Moscovitch (2004) Psychopharmacology 171(4):390-7 [PubMed]
- Bupropion
- Specifically FDA labeled for preventing Seasonal Affective Disorder
- Effective when started September to November before the onset of SAD symptoms
- Selective Serotonin Reuptake Inhibitor (SSRI)
- Other medications
- Insufficient evidence to support Vitamin D Supplementation
- Indications
- Adjunctive measures
- Exercise
- Sleep Hygiene
- Avoid prolonged Screen Time before bed
- Maintain a regular sleep-wake cycle
- Stress management and Relaxation Techniques
- Daytime outdoor activity during seasons with shorter day lengths
- Increased overall lighting in the home
IX. Resources
- Canadian Consensus Guidelines For Treating Seasonal Affective Disorder (1999)
X. References
- Zal (March 1997) Consultant, 641-9
- APA (1994) DSM IV, APA, p. 317-91
- (2021) Presc Lett 28(12): 69
- Galima (2020) Am Fam Physician 102(11): 668-72 [PubMed]
- Kurlansik (2012) Am Fam Physician 86(11): 1037-41 [PubMed]
- Lurie (2006) Am Fam Physician 74:1521-24 [PubMed]
- Partonen (1998) Lancet 352:1369-74 [PubMed]
- Saeed (1998) Am Fam Physician 57(6): 1340-6 [PubMed]