Examining the Link Between Depression and Seasonal Allergies

Sponsor

University of Maryland, Baltimore (Other)

Overall Status

Completed

CT.gov ID

NCT00770068

Collaborator

National Institute of Mental Health (NIMH) (NIH)

100

Enrollment

Locations

128.9

Duration (Months)

Patients Per Site

0.4

Patients Per Site Per Month

Study Details

Study Description

Brief Summary

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.

Condition or Disease	Intervention/Treatment	Phase
Depression

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.

Study Design

Study Type:

Observational

Actual Enrollment :

100 participants

Observational Model:

Cohort

Time Perspective:

Prospective

Official Title:

Seasonality of Depression and Airborne Allergens

Study Start Date :

Jul 15, 2006

Actual Primary Completion Date :

Apr 11, 2017

Actual Study Completion Date :

Apr 11, 2017

Arms and Interventions

Arm	Intervention/Treatment
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

Outcome Measures

Primary Outcome Measures

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

Secondary Outcome Measures

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

Eligibility Criteria

Criteria

Ages Eligible for Study:

18 Years to 64 Years

Sexes Eligible for Study:

All

Accepts Healthy Volunteers:

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

Locations

	Site	City	State	Country	Postal Code
1	National Center for the Treatment of Phobias, Anxiety, and Depression	Washington	District of Columbia	United States	20037
2	University of Maryland	Baltimore	Maryland	United States	21201