INCLUSION CRITERIA:

Patients with schizophrenia will be recruited exclusively from among inpatients who are participating in clinical studies of the Clinical Brain Disorders Branch of NIMH under NIH protocol #89-M-0160 (Egan 1999a) and for whom genetic data is already available.

Normal volunteers will be recruited exclusively from among individuals who have volunteered for studies under NIH protocol #95-M-0150 (Egan 1999b) as normal control subjects and for whom genetic data is already being analyzed.

EXCLUSION CRITERIA:

Pregnancy: All women of childbearing age must undergo a pregnancy test prior to injection or radioactive isotope. 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.

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

Iodine sensitivity: Subjects with a prior reaction to iodine, iodine compounds, or shellfish will be excluded from this study. Also, subjects with a history of thyroid disease or dysfunction will be excluded from this study.

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

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

INCLUSION CRITERIA FOR PATIENTS WITH SCHIZOPHRENIA:

Prior participation as a NIMH inpatient under NIH protocol #89-M-0160.

Schizophrenia diagnosis according to DSM-IV criteria.

EXCLUSION CRITERIA FOR PATIENTS WITH SCHIZOPHRENIA:

Coexistence of another mental illness at the time of the study. If the patient has experienced other mental illnesses in the past (e.g. a learning disability or major depression), then this should be judged to be fully recovered.

INCLUSION CRITERIA FOR NORMAL CONTROLS:

Prior participation as a normal volunteer under NIH protocol #95-M-0150.

No Axis I or Axis II diagnoses.

EXCLUSION CRITERIA FOR NORMAL CONTROLS:

Subjects with an Axis I or 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.