PET scans reveal how the brain thinks in health and disease
NCT ID NCT00001258
First seen Jun 27, 2026 · Last updated Aug 13, 2026 · Updated 10 times
Summary
This study used PET scans to measure blood flow in the frontal lobe while participants performed thinking tasks. It included healthy volunteers and people with schizophrenia or Parkinson's disease. The goal was to understand how the frontal lobe works during cognitive activities and how drugs might affect it.
What this could mean
Our plain-language read of the trial. This is informational only, not medical advice or a prediction.
- Active substance
- Oxygen-15 water
- What this could lead to
- If successful, this could help researchers understand how the frontal lobe works in thinking and how it is affected in neuropsychiatric disorders.
- What could go wrong
- This is an observational imaging study, not a treatment trial. It may not lead directly to new therapies or change patient care.
This is an AI summary of the original study and may miss details. Read our disclaimer.
Study facts
What this study's own registry entry says, in plain language.
- Participants
-
1,039 people
The number who actually took part.
- Started
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Nov 1993
- Lead sponsor
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A government research agency
The lead sponsor is the US National Institutes of Health.
Who can take part
This study's own entry requirements. Only the study team can say for certain whether you qualify.
Who is studied
Patients with schizophrenia spectrum disorder and normal volunteers
- Ages
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18 to 90 years
- Sex
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Anyone
- Healthy volunteers
-
Not accepted
This study is not open to healthy volunteers. The entry requirements below say who it is open to.
Show the full entry requirements Hide the full entry requirements
Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.
* INCLUSION/EXCLUSION CRITERIA: Participants in this study will reflect the diversity of the community. No one will be excluded or discriminated against on the grounds of race, gender, religion or ethnic background. Every attempt will be made to include women and minorities in the study population. Children will not be studied because of radiation exposure limits on this group. Normal control subjects will be recruited through the NIH normal volunteer program, through advertisement in the community and primarily through the "Genetic Study" under protocol 95-M-0150. An additional control group of non-schizophrenic siblings of patients with schizophrenia will also be recruited (from the community and protocol 95-M-0150, A Neurobiological Investigation of Patients with Schizophrenia Spectrum Disorders and Their Siblings). Control subjects will be matched to the patient groups by age, sex, and handedness. Control subjects with a history of psychiatric or neurologic disorders or medical illnesses or surgeries that might have relevance to the investigation of brain physiology will be excluded. Control subjects requiring continuous treatment with prescribed medications that impact cerebral blood flow and metabolism will be excluded. Control subjects unable to refrain from nicotine or caffeine for at least 4 hours or alcohol for at least 12 hours prior to the PET study will be excluded. Control subjects with exposure to other substances with relevance to cerebral blood flow and metabolism, such as some over-the-counter medications, will be reviewed in each individual case, to ensure that an adequate period of abstinence will precede the performance of the PET study. Patients with schizophrenia spectrum disorder will be recruited from the inpatient population of the NIMH Wards at the NIH Clinical Center and from the sibling study protocol 95-M-0150. Diagnoses will be made by the NIMH clinical staff in accordance with DSM-IV(R). Patients with history of neurological illness other than those of interest to the study, or other medical illness or surgery that might have impact on the study of brain physiology, will be excluded. Inpatients on the NIMH Schizophrenia Ward will have signed protocol 89-M-0160 ("Inpatient Evaluation of Neuropsychiatric Patients") and will be studied after being free of neuroleptic treatment for at least two weeks. They may also be studied when they are stabilized on medication; however, no treatment decisions, for inpatients or outpatients, will be based upon this study. All inpatients will be carefully monitored on the NIMH/NIH wards as per protocol 89-M-0160. Additional neuropsychiatric patients (such as those with affective disorder, Parkinson's Disease, special genetic disorders (e.g. William's Syndrome), and other neuropsychiatric disorders) will be recruited from the medical community, from NIH inpatient and outpatient services, and through the National Alliance for the Mentally Ill (NAMI). Patients will be identified by the presence of typical symptoms and signs elicited by history and examination. Diagnoses will conform to accepted diagnostic guidelines where applicable. Such patients will be excluded from study for 1) history of psychiatric or neurologic disorders other than those under investigation, 2) medical illnesses or surgeries that might have relevance to the investigation of brain physiology, 3) current medications that are not under investigation and that have relevance to cerebral blood flow and metabolism, and 4) IQ less than 70. Patients unable to refrain from nicotine or caffeine for at least 4 hours or alcohol for at least 12 hours prior to the PET study will be excluded. Patients with exposure to other substances with relevance to cerebral blood flow and metabolism, such as some over-the-counter medications, will be reviewed in each individual case, to ensure that an adequate period of abstinence will precede the performance of the PET study. Outpatients may be admitted overnight if necessary or otherwise applicable (e.g. those from out of town). No cognitively impaired nonschizophrenic subjects are studied in this protocol. For Parkinson's Disease patients, information is obtained from referring physicians, from NIH medical records for participants already enrolled in the NIH system, and by phone from the potential participant. Further assessment is carried out by a neurologist or psychiatrist upon arrival at the NIH. For Williams syndrome patients, IQ testing is done off-site by a certified clinical neurophysiologist who refers patients for our study and who has followed large numbers of these rare individuals for years.
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Conditions
The condition(s) this trial relates to.
As listed by the trial registrant
The condition terms exactly as the trial's registrant entered them.
Contacts and locations
Locations
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National Institutes of Health Clinical Center
Bethesda, Maryland, 20892, United States
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