Examining the Link Between Depression and Seasonal Allergies
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ClinicalTrials.gov Identifier: NCT00770068 |
Recruitment Status :
Completed
First Posted : October 9, 2008
Last Update Posted : November 21, 2019
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Condition or disease |
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Depression |
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.
Study Type : | Observational |
Actual Enrollment : | 100 participants |
Observational Model: | Cohort |
Time Perspective: | Prospective |
Official Title: | Seasonality of Depression and Airborne Allergens |
Study Start Date : | July 15, 2006 |
Actual Primary Completion Date : | April 11, 2017 |
Actual Study Completion Date : | April 11, 2017 |

Group/Cohort |
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Experimental group
All participants testing positive for tree and ragweed pollen allergies, as determined by levels of immunoglobulin E (IgE) antibodies
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Control group
All participants testing negative for tree and ragweed pollen allergies, as determined by levels of IgE antibodies
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- 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 ]
- 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

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Ages Eligible for Study: | 18 Years to 64 Years (Adult) |
Sexes Eligible for Study: | All |
Accepts Healthy Volunteers: | No |
Sampling Method: | Non-Probability Sample |
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

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): 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 |
Principal Investigator: | Teodor T. Postolache, MD | University of Maryland, Baltimore |
Other Publications:
Responsible Party: | Teodor Postolache, Professor, University of Maryland, Baltimore |
ClinicalTrials.gov Identifier: | NCT00770068 |
Other Study ID Numbers: |
R21MH075891 ( U.S. NIH Grant/Contract ) R21MH075891 ( U.S. NIH Grant/Contract ) H26191 DATR A2-AID |
First Posted: | October 9, 2008 Key Record Dates |
Last Update Posted: | November 21, 2019 |
Last Verified: | November 2019 |
Mood Disorders Major Depressive Disorder Bipolar Disorder Tree Pollen Ragweed Pollen |
Rhinitis Allergic Seasonal Allergens |
Depression Depressive Disorder Behavioral Symptoms Mood Disorders Mental Disorders |