CO2 Inhalation and Risk for Panic Disorder

Objective:

To examine respiratory/physiological and subjective responding as well as genetic transmission among offspring of parents with a history of or current panic disorder (PD) diagnosis to determine whether diagnoses/symptoms, endophenotypes, or genetic profiles in offspring is differentially related to parent PD subtypes (i.e., respiratory and non-respiratory panic).

Study population:

Approximately 400 offspring of about 200 parents with current or past PD. Approximately 200 offsping/100 parents with PD will be enrolled at NIH/NIMH and the remainder at Virginia Commonwealth University in Richmond, VA.

Design:

A high-risk family design will be used wherein parents with either a current or past diagnosis of PD who have an offspring(s) (ages 9 to 20) will be recruited.

Outcome measures:

Outcome measures will include physiological recordings of respiratory, cardiac, and electrodermal responding during a 10 minute baseline followed by 15 minutes of 5% carbon dioxide enriched air (CO2). Research participants also will complete parent and child self-report measures and provide a DNA sample using a saliva protocol. A full listing of self-reports is provided in the Outcome Measures Section.

Objective:

The objective of this study is to examine respiratory/physiological and subjective responding as well as genetic transmission among offspring of parents with a history of or current panic disorder (PD) diagnosis. Our goal is to determine whether diagnoses/symptoms, endophenotypes, or genetic profiles in offspring is differentially related to parent PD subtypes (i.e., respiratory and non-respiratory panic).

Study population:

Approximately 80 offspring between the ages of 9 and 20 years of age who have a parent with a current or past history of PD will be recruited. Approximately 40 offspring will be enrolled at NIH/NIMH and the remainder at Virginia Commonwealth University in Richmond, VA.

Design:

Offspring(s) between the ages of 9 to 20 who have a parent with a history of PD will be recruited. A complete psychiatric history will be obtained on all child participants. Child participants also will complete questionnaire measures, provide a sample of DNA, and participate in a carbon dioxide CO(2) lab challenge. The CO(2) lab challenge is the primary outcome measure.

Outcome measures:

Our primary outcome measures include physiological recordings of respiratory, cardiac, and electrodermal responding during a 10 minute baseline followed by 15 minutes of 5% carbon dioxide enriched air (CO(2). Research participants also will complete parent and child self-report measures and provide a DNA sample using a saliva protocol. A full listing of self-reports is provided in the Outcome Measures Section.

• Abrams K, Rassovsky Y, Kushner MG. Evidence for respiratory and nonrespiratory subtypes in panic disorder. Depress Anxiety. 2006;23(8):474-81.
• Battaglia M, Ogliari A, Harris J, Spatola CA, Pesenti-Gritti P, Reichborn-Kjennerud T, Torgersen S, Kringlen E, Tambs K. A genetic study of the acute anxious response to carbon dioxide stimulation in man. J Psychiatr Res. 2007 Dec;41(11):906-17. Epub 2007 Jan 24.
• Biber B, Alkin T. Panic disorder subtypes: differential responses to CO2 challenge. Am J Psychiatry. 1999 May;156(5):739-44.

• INCLUSION CRITERIA:
• Children age 9-18, and young adults 18-20 who have a parent with a past or current history of PD.

EXCLUSION CRITERIA (ALL PARTICIPANTS):

• Serious, unstable illnesses including hepatic, renal, gastroenterologic, respiratory, cardiovascular, endocrinologic, neurologic, immunologic, or hematologic disease, one or more past seizures without a clear and resolved etiology,
• Subjects who are currently at high risk for homicide or suicide,
• Subjects with symptoms of psychosis
• Subjects with current DSM-IV substance abuse or dependence within the past year.
• Subjects with IQ< 70,

ADDITIONAL EXCLUSION CRITERIA FOR CHILDREN:

• mania,
• pervasive developmental disorder,
• use of psychotropic medication,
• Child participants must be psychotropic free for at least 14 days prior to the CO(2) challenge session.
• For children taking fluoxetine, they must be free of this medication for at least 4 weeks.
• The proband parent must be a legal guardian of the child to qualify for the study.

Offspring passing screening criteria will be scheduled for an intake to complete a clinical interview, questionnaires, and CO(2) challenge task with assessment of respiratory physiology.