Iowa Longitudinal Study (NDA 2125)
Phenomenology and Classification of Schizophrenia (Iowa Longitudinal Study)
University of Iowa prospective study of first-episode schizophrenia patients followed for up to 18 years with repeated 1.5T structural MRI, symptom ratings and cognitive tests. The NIMH Data Archive shares data from 275 subjects, 267 of them with images.
Overview
The Iowa Longitudinal Study follows people with a first episode of schizophrenia from their first psychiatric admission at the University of Iowa over many years. It tracks four areas: symptoms, psychosocial function, brain morphology from structural MRI, and cognition from neuropsychological and experimental tests. The study was funded by two NIMH grants led by Nancy Andreasen, and its data are deposited in NIMH Data Archive (NDA) collection 2125.
Composition
NDA lists 275 shared subjects. 267 of them have records in the NDA Image data structure, and the remaining 8 have clinical data only. The shared clinical structures cover symptom interviews (CASH, PSYCH and PSYCH-up instruments, SAPS/SANS) and the WAIS-R, each for 60 to 163 subjects. The collection page does not say whether healthy controls are part of the shared data, nor how many visits per subject are included.
The full study enrolled 542 first-episode patients between 1987 and 2007, recruited from consecutive inpatient admissions, and rated them every six months. MRI and cognitive testing were repeated at intake and at 2, 5, 9, 12, 15 and 18 years. A 2011 analysis used 952 scans from 202 patients and 125 community controls. These cohort numbers come from the papers and describe more people than the NDA release.
Acquisition
The study used two coronal protocols at 1.5T. The earlier one ran on a GE Signa and acquired T1-, T2- and proton density weighted images (T1 voxels 1.0 x 1.0 x 1.5 mm). The later one ran on a Siemens Avanto and acquired T1- and T2-weighted images (T1 voxels 0.625 x 0.625 x 1.5 mm). Each subject stayed on the protocol they started with. The NDA page does not state which protocols or file formats the shared images use.
Known limitations
- Access requires an approved NDA Data Access Request and Data Use Certification.
- The link between the shared subjects and the cohorts described in the papers is not documented, so cohort-level demographics are not given here as counts for the release.
- The supporting instrument documents on NDA are restricted to qualified researchers.
- Images were acquired over two decades on scanners that changed during the study.
Cohort
Aggregate numbers from the sources below. Bars are relative to the 275 subjects.
Modality
subjects
- MRI 267 97%
License and access
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A research proposal is reviewed and approved
NIMH Data Archive Data Use Terms and Conditions (Data Use Certification)
Terms every NIMH Data Archive data access request accepts. Data are for research, scholarship or teaching; they may only be shared with collaborators who hold their own access; re-identification is forbidden; each publication needs an NDA Study linked to the data and an acknowledgement; downloaded data must be deleted when the research ends or after the one-year access period.
The data are held in NIMH Data Archive collection 2125 and are accessed under the NDA Data Use Certification.
What you can do
- Not stated
- Not stated
- Not stated
- Conditional
- Conditional
What you can share
- No
- Conditional
- Share trained models Not stated
What you must do
- Yes
- Share alike No
- Yes
- Conditional
- Manuscript review No
- No
- Yes
- Yes
Limits
- Yes
- Location limits No
Citation
Andreasen N. Phenomenology and Classification of Schizophrenia (Iowa Longitudinal Study). NIMH Data Archive collection 2125 (2015). doi:10.15154/z32v-tv80
All numbers
Every number on this page, as stored in stats.csv, with its source.
| Measure | Breakdown | Value | Source |
|---|---|---|---|
| Subjects | total Subjects shared through the NIMH Data Archive | 275 | nda-collection-2125 General tab (Subjects Shared) |
| Subjects | modality=MR Subjects in the shared NDA Image data structure | 267 | nda-collection-2125 Shared Data tab (Image) |
Sources
The keys used in the table above.
- nda-collection-2125 NIMH Data Archive collection 2125 page, General, Shared Data and Data Expected tabs website
- gupta1997 Gupta et al. 1997, The Iowa Longitudinal Study of Recent Onset Psychosis, Schizophrenia Research paper
- andreasen2011 Andreasen et al. 2011, Progressive brain change in schizophrenia, Biological Psychiatry (author manuscript PMC3496792) paper