An observational study in Schizoaffective Disorder and Schizophrenia, sponsored by National Institute of Mental Health (NIMH). Completed at 1 site in United States. Open to participants aged 18 Years to 55 Years. Per ClinicalTrials.gov, last updated 2026-10-02.
Sponsored by National Institute of Mental Health (NIMH) · Observational
This large ongoing study at NIMH investigates the neurobiology of schizophrenia by identifying susceptibility genes, evaluating their impact on brain function to better understand how to treat and prevent this illness.
Objective: Schizophrenia is a complex genetic disorder which likely involves many genes each producing a slight increase in risk. Finding weak-acting genes in complex genetic disorders has been challenging and will likely require a number of approaches and large clinical samples. Several strategies have emerged recently that appear to markedly improve the power of genetic studies for detecting such genes. These include using association (rather than linkage) and using intermediate phenotypes in addition to DMS-IV diagnosis.
Study Population: We propose to take advantage of these techniques by studying quantitative traits related to schizophrenia in patients, siblings, and controls.
Design: We will employ an association design, rather than linkage. Traits will include quantifiable neurobiological variables that have been implicated previously as possible phenotypes related to schizophrenia. These include tests of attention and cognition.
Outcome Measure: We will use several statistical methods to show that specific genetic polymorphisms affect these phenotypes, including case control and family based association studies.
1,587 studies on the registry are indexed under Psychotic Disorders; 281 are open to participants now.
This study's enrollment of 4,914 is above the median of 123 across 221 observational studies indexed under Psychotic Disorders.
Browse Psychotic Disorders studies →National Institute of Mental Health (NIMH) is the lead sponsor of 367 studies on the registry; 45 are open to participants now.
Of its 25 completed or terminated interventional studies of FDA-regulated products, 24 (96%) have results posted.
Counted across the registry records on this site, refreshed daily.
Probands, healthy controls, siblings, parents
Inclusion criteria for Siblings (probands and unaffected siblings):
Exclusion Criteria for Siblings (probands and unaffected siblings):
Siblings who do not qualify for the 2-day or 1-day study, may participate in the limited phenotyping arm in which only a psychiatric interview and a blood draw for genetic analysis (SCID-DNA) will be performed, case control analysis or be included as part of a trio (one parent, one sibling, one patient) to study genetic transmission from parents to offsprings.. All parents are eligible for the study.
Inclusion Criteria. Healthy Volunteers/Controls
To be eligible for this research study, healthy volunteers must be:
Healthy Controls Exclusion Criteria:
They will not be eligible if:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
The American Psychiatric Association’s manual of mental health diagnoses. DSM-5 (2013, revised as DSM-5-TR in 2022) replaced DSM-IV, and some studies still name the older edition. “Meets DSM criteria for …” means diagnosed by that edition’s diagnostic criteria, usually by a clinician in an interview.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
DSM diagnostic criteria
The American Psychiatric Association’s manual of mental health diagnoses. DSM-5 (2013, revised as DSM-5-TR in 2022) replaced DSM-IV, and some studies still name the older edition. “Meets DSM criteria for …” means diagnosed by that edition’s diagnostic criteria, usually by a clinician in an interview.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Male and female adult healthy volunteers
Parents of Probands and siblings for the purposes of DNA collection
Adult Subjects with Schizophrenia Spectrum Disorders
Adult siblings of Probands
Genetic Polymorphisms affect phenotypes
genotyping analysis
Time frame: At time of study participation
PANSS, AIMS, GAF
PANSS, AIMS, GAF
Time frame: At time of study participation
Plan to share: No
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
This study is completed, as verified in Jan 2026. You cannot join it, but the record below documents what was studied.
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National Institute of Mental Health (NIMH) →