NIH Clinical Research Studies

Protocol Number: 02-M-0162

Active Followup, Protocols NOT Recruiting New Patients

Title:
Tryptophan Depletion PET Study in Remitted Depressed Subjects and Healthy Controls, and GABA MRS Study in Remitted and Currently Depressed Subjects and Healthy Controls
Number:
02-M-0162
Summary:
Serotonin is a chemical involved in regulation of emotions, anxiety, sleep, stress hormones, and other body functions. The purpose of this study is to use a procedure called tryptophan depletion to study the function of serotonin in people with depression and in healthy volunteers.

Major depressive disorder (MDD) has been associated with reduced functioning of central serotonergic systems. Tryptophan depletion (TD) is a procedure used to investigate the relationship between serotonergic function and depression. Evidence suggests that the mood lowering effects of TD depend upon family history and differences in genes for a specific protein called 5-HTTLPR. Healthy females with a particular gene for 5-HTTLPR and a family history of mood disorders appear to be at a greater risk for the development of depressive symptoms during TD. This study will use positron emission tomography (PET) scans of the brain to investigate the effect of variant 5-HTTLPR genotypes on response to TD. The relationship between 5-HTTLPR genotypes and the effect of TD on brain activity in individuals with different 5-HTTLPR genes will be determined. This study will also examine how the reduced serotonin function that occurs in MDD affects the brain's response to sensory stimulation.

Participants in this study will be screened by telephone about their psychiatric and medical history, current emotional state, anxiety and sleep patterns, and family history of psychiatric disorders. At study entry, participants will have an interview, physical examination, electrocardiogram (EKG), and blood and laboratory tests. Menstruating women will have a pregnancy test and tests to determine menstrual phase and time of ovulation. At the second clinic visit, participants will undergo tests of intelligence and cognitive abilities and a magnetic resonance imaging (MRI) scan of the brain. Prior to Visits 3 and 4, participants will collect their saliva and urine. Menstruating women will have a pregnancy test. At Visits 3 and 4, participants will undergo TD studies and PET scanning. During one of these visits, participants will take capsules of an amino acid. On the other day, they will take lactose capsules. Throughout the study, participants will be asked about their emotional state, anxiety, ability to concentrate, and well being.

Sponsoring Institute:
National Institute of Mental Health (NIMH)
Recruitment Detail
Type: Completed Study; data analyses ongoing
Gender: Male & Female
Referral Letter Required: No
Population Exclusion(s): Children

Eligibility Criteria: This study is not currently recruiting new subjects. If you have questions about participating in a study, please contact the Patient Recruitment and Public Liaison Office, CC.
Special Instructions:
Currently Not Provided
Keyword(s):
Depression
Tryptophan Depletion
PET
Serotonin
Pathophysiology
Emotional Stimuli
GABA MRS
Recruitment Keyword(s):
Depression
MDD
Healthy Volunteer
HV
Normal Control
Condition(s):
Depression, Involutional
Healthy
Investigational Drug(s):
[O-15] Water
[F-18] FDG
Investigational Device(s):
None
Interventions:
None
Supporting Site:
National Institute of Mental Health

Contact(s):
This study is not currently recruiting new subjects. If you have questions about participating in a study, please contact the Patient Recruitment and Public Liaison Office, CC.

Citation(s):
Bowen DM, Najlerahim A, Procter AW, Francis PT, Murphy E Circumscribed changes of the cerebral cortex in neuropsychiatric disorders oflater lifeProc Natl Acad Sci U S A 1989 Dec;86(23):9504-8

Rajkowska G, Miguel-Hidalgo JJ, Wei J, Dilley G, Pittman SD, Meltzer HY,Overholser JC, Roth BL, Stockmeier CA Morphometric evidence for neuronal and glial prefrontal cell pathology in majordepressionBiol Psychiatry 1999 May 1;45(9):1085-98

Coppen A, Eccleston EG, Peet M Total and free tryptophan concentration in the plasma of depressive patientsLancet 1973 Jul 14;2(7820):60-3 No abstract available

Active Followup, Protocols NOT Recruiting New Patients

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