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Seasonal Depression

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Seasonal Depression, Seasonal Affective Disorder

  • Definitions
  1. Seasonal Affective Disorder
    1. Depressed mood that occurs within a specific time window of the year (typically fall-winter)
  • Epidemiology
  1. Annual Incidence in United States: <5%
  2. Lifetime Prevalence: 0.5 to 2.4%
  3. Of those with Major Depression, 10-20% have a seasonal pattern to their Major Depression
  4. Peak Incidence
    1. Fall and winter (October to February)
    2. Variation occurring Spring-Summer is less common
  5. Gender
    1. Female more than Male by factor of 4
  6. Age
    1. Uncommon under age 15 years
    2. Uncommon in elderly
  7. Family History
    1. Identical twin studies suggest a genetic predisposition
      1. Madden (1996) Arch Gen Psychiatry 53(1): 47-55 [PubMed]
  • Symptoms
  1. Regular temporal relationship of Major Depression onset
    1. Occurs at the same time every year
    2. Usually occurs in fall or winter
    3. Unrelated to seasonal life stressors
  2. Full remission occurs at a specific time of year
  3. Two Seasonal Major Depression episodes in last 2 years
  4. No Non-seasonal episodes of Major Depression in 2 years
  5. Seasonal Depression episodes outnumber non-seasonal
  • Diagnosis
  • Instruments
  1. Standard depression tools may be used to diagnosis presence and severity of Major Depression
  2. Patient Health Questionaire 9 (PHQ-9)
  3. Zung Self-Rating Depression Scale
  4. Beck Depression Inventory
  5. Hamilton Depression Scale
  6. Avoid SPAQ for clinical diagnosis (intended for research settings, and variable efficacy in practice)
  • Management
  1. Light Therapy (preferred therapy)
    1. Timing
      1. Start therapy in early fall and continue until spring
      2. Light exposure early in day
        1. Synchronizes with circadian rhythm
        2. Terman (2001) Arch Gen Psychiatry 58:69-75 [PubMed]
    2. Dose and Duration (white fluorescent light with UV wavelengths filtered out)
      1. Exposure to 10,000 lux for 30 minutes per morning (Preferred) or
      2. Exposure to 2500 lux for 2 hours per morning (Dawn simulation at end of sleep cycle and early in day)
      3. Contrast with mid-day sun intensity (50,000 to 100,000 lux)
    3. Technique
      1. Keep eyes open during this time
      2. Do not need to stare at the light
  2. Cognitive behavior therapy
    1. Cognitive Behavioral Therapy is associated with significant improvements in the short and longterm
    2. Rohan (2009) Behav Ther 40(3): 225-238 [PubMed]
    3. Rohan (2015) Am J Psychiatry 172(9):862-9 [PubMed]
    4. Rohan (2016) Am J Psychiatry 173(3): 244-51 [PubMed]
  3. Pharmacotherapy
    1. Indications
      1. High Suicide Risk
      2. Significant functional Impairment
      3. Recurrent moderate to severe Major Depression
      4. Patient preference
      5. Failure to respond to Light Therapy, Psychotherapy
    2. Agents
      1. Selective Serotonin Reuptake Inhibitor (SSRI)
        1. Thaler (2011) Cochrane Database Syst Rev (12):CD008591 [PubMed]
        2. Moscovitch (2004) Psychopharmacology 171(4):390-7 [PubMed]
      2. Bupropion
        1. Specifically FDA labeled for preventing Seasonal Affective Disorder
        2. Effective when started September to November before the onset of SAD symptoms
          1. Gartlehner (2019) Cochrane Database Syst Rev (3): CD011268 [PubMed]
    3. Other medications
      1. Insufficient evidence to support Vitamin D supplementation
  4. Adjunctive measures
    1. Exercise
    2. Sleep Hygiene
    3. Avoid prolonged Screen Time before bed
    4. Maintain a regular sleep-wake cycle
    5. Stress management and Relaxation Techniques
    6. Daytime outdoor activity during seasons with shorter day lengths
    7. Increased overall lighting in the home
  • Resources
  1. Canadian Consensus Guidelines For Treating Seasonal Affective Disorder (1999)
    1. http://www.ubcmood.ca/sad/CCG%20SAD%201999.pdf