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Examining the Link Between Depression and Seasonal Allergies

This study has been completed.
National Institute of Mental Health (NIMH)
Information provided by (Responsible Party):
Teodor Postolache, University of Maryland Identifier:
First received: October 8, 2008
Last updated: April 10, 2017
Last verified: April 2017
This study will examine whether spring and fall seasonal depression in individuals with high sensitivity to pollen is linked to seasonal increases in tree and ragweed pollen.


Study Type: Observational
Study Design: Observational Model: Cohort
Time Perspective: Prospective
Official Title: Seasonality of Depression and Airborne Allergens

Further study details as provided by University of Maryland:

Primary Outcome Measures:
  • Hamilton Rating Scale for Depression-Seasonal Affective Disorder Version (SIGH-SAD) [ Time Frame: Measured before and then during the peak fall or spring pollen period ]

Secondary Outcome Measures:
  • Hypomania Interview Guide (HIGH-SAD) [ Time Frame: Measured before and then during the peak fall or spring pollen period ]
  • Burns Anxiety Inventory [ Time Frame: Measured before and then during the peak fall or spring pollen period ]
  • Buss Aggression Questionnaire [ Time Frame: Measured before and then during the peak fall or spring pollen period ]
  • Allergy Symptom Severity Assessment (ASSA) Questionnaire [ Time Frame: Measured before and then during the peak fall or spring pollen period ]
  • Serum cytokine, tryptophan (TRP), and kynurenine (KYN) concentrations [ Time Frame: Measured before and then during the peak fall or spring pollen period ]
  • Nasal secretion test [ Time Frame: Measured before and then during the peak fall or spring pollen period ]
  • Sleep logs [ Time Frame: Measured over 1 week during pre- or post-pollen and peak pollen period ]
  • Actiwatch [ Time Frame: Measured after the pre-pollen and peak pollen visits for 24 hours a day for 1 week ]
  • Beck Depression Inventory II (BDI-II) [ Time Frame: Measured during the peak pollen period ]
  • Pittsburgh Sleep Quality Index (PSQI) [ Time Frame: Measured during the peak pollen period ]

Biospecimen Retention:   Samples Without DNA

Enrollment: 100
Study Start Date: July 15, 2006
Study Completion Date: April 11, 2017
Primary Completion Date: April 11, 2017 (Final data collection date for primary outcome measure)
Experimental group
All participants testing positive for tree and ragweed pollen allergies, as determined by levels of immunoglobulin E (IgE) antibodies
Control group
All participants testing negative for tree and ragweed pollen allergies, as determined by levels of IgE antibodies

Detailed Description:

Those who suffer from depression have their normal lives interrupted by symptoms such as persistent sad thoughts, inability to feel pleasure, and potential suicide. Suicide and depression peak in the spring and fall. Worsening of depression, admission to a hospital for depression and bipolar depression, and use of electroconvulsive therapy for treatment of depression all peak in the spring. Although seasonal affective disorder (SAD), in which depression corresponds with seasonal changes, is commonly associated with the winter subtype, SAD is actually more prevalent as the spring subtype.

Allergies, which also peak in the spring and fall, have been linked to depression. Allergic reactions release cytokines, which are proteins that mediate the immune system response when a foreign substance enters the body. Previous studies have found both that an increase in cytokines in otherwise healthy individuals causes depressive symptoms and that cytokines cause the chemical tryptophan (TRP) to switch from producing serotonin, a neurotransmitter associated with feelings of well-being, to producing kynurenine (KYN), a potentially toxic chemical. To determine whether and to what extent allergies are linked to depression, this study will compare depression levels of participants with and without allergies before and during peak times for seasonal allergies. Results from this study may be used in further research to examine the effects of allergy prevention on depression.

Participants in this study will meet with researchers three times. At the first visit, they will be screened for allergies and give their demographic information. The timing of the second and third visits will depend on each participant's allergies. Those with spring allergies will be tested before and then during the spring allergy season. Those with fall allergies or with no allergies will be tested before and then during the fall allergy season. On the second and third visits questionnaires and clinical interviews will assess depression symptoms, and blood tests will be performed to measure chemical levels of cytokines, TRP, and KYN. During these visits participants will also be asked to complete a sleep log for 1 week. This will entail describing their sleep, activity, caffeine consumption, alcohol consumption, and use of sleep medications. A subgroup will wear an Actiwatch device, which electronically monitors sleep and wakefulness cycles, for 1 week, 24 hours a day.


Ages Eligible for Study:   18 Years to 64 Years   (Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No
Sampling Method:   Non-Probability Sample
Study Population
A community sample will be recruited via local press and radio advertising. Referrals from mental health providers will be used to supplement this population.

Inclusion Criteria:

  • Diagnosis of major depressive disorder or bipolar disorder

Exclusion Criteria:

  • Pregnancy or intention to become pregnant within the duration of the study
  • Dependence on alcohol, cocaine, stimulants, benzodiazepines, marijuana, or opiates
  • Major medical illness, including cancer, hepatitis, and autoimmune disease
  • A winter subtype of seasonal affective disorder
  • Diagnosis of psychotic disorder
  • Positive result in Phadiatop allergy test, but negative result in tree or ragweed pollen IgE test
  Contacts and Locations
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Please refer to this study by its identifier: NCT00770068

United States, District of Columbia
National Center for the Treatment of Phobias, Anxiety, and Depression
Washington, District of Columbia, United States, 20037
United States, Maryland
University of Maryland
Baltimore, Maryland, United States, 21201
Sponsors and Collaborators
University of Maryland
National Institute of Mental Health (NIMH)
Principal Investigator: Teodor T. Postolache, MD University of Maryland
  More Information