Abnormalities in the re-uptake of dopamine and serotonin have been described in various neuropsychiatric disorders and substance abuse. [I-123] Beta-CIT is a recently developed radioligand for SPECT imaging of dopamine and serotonin transporters. [I-123]Beta-CIT SPECT has been used at the SPECT-lab of the Clinical Brain Disorders Branch in over fifty subjects without adverse events. Due to the trace concentrations used, a pharmacological effect of Beta-CIT is unlikely and has not been observed. The purpose of this study is to use Beta-CIT and SPECT to study the expression of dopamine and serotonin transporters in vivo in normal controls and various patient populations to address hypothesized abnormalities of the transporters in different disorders and to understand the effects of genetic variations in the genes of these transporters on their in vivo expression.

Abnormalities in the re-uptake of dopamine and serotonin have been described in various neuropsychiatric disorders and substance abuse. [I-123] Beta-CIT is a recently developed radioligand for SPECT imaging of dopamine and serotonin transporters. [I-123]Beta-CIT SPECT has been used at the SPECT-Lab of the Clinical Brain Disorders Branch in over fifty subjects without adverse events. Due to the trace concentrations used, a pharmacological effect of Beta-CIT is unlikely and has not been observed. The purpose of this study is to use Beta-CIT and SPECT to study the expression of dopamine and serotonin transporters in vivo in normal controls and various patient populations to address hypothesized abnormalities of the transporters in different disorders and to understand the effects of genetic variations in the genes of these transporters on their in vivo expression.

INCLUSION CRITERIA:

No Axis I or Axis II diagnoses.

EXCLUSION CRITERIA FOR ALL SUBJECTS:

If the pregnancy test is positive or if the woman has reason to believe she might be pregnant, she will be excluded from this study.

Women who are breastfeeding will be excluded from this study to avoid unwarranted risk to their children.

Subjects with a prior reaction to iodine, iodine compounds, or shellfish will be excluded from this study.

Subjects with a history of thyroid disease or dysfunction will be excluded from this study.

Subjects with a history of recent substance abuse will be excluded from this study.

Subjects with metal objects in their bodies as specified in our MRI protocol (91-M-0124) will be excluded from this study.

If a structural abnormality of the brain is detected on MRI, subjects will be excluded from the study.

EXCLUSION CRITERIA FOR NORMAL CONTROLS:

Subjects with an Axis I or Axis II disorder will be excluded.

Subjects with concomitant medical or neurological disorders which require ongoing medication, or which may affect the central nervous system will be excluded.