CO2 Inhalation and Risk for Panic Disorder

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.

- 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.