Data acquisition for this study is complete. There are opportunities for graduate student and post-doctoral involvement in new ways to analyze the data for publication. The study tested the following aims:
Schizophrenia is a disorder of cognition. Cognitive impairment is the strongest contributor to burden of illness. Yet, there are currently no routine tests for diagnosing cognitive impairments in schizophrenia, nor treatments for ameliorating these impairments.
The evidence base for developing new cognitive treatments requires cognitive measures that link to functional capacity on the one hand, and to brain changes involved in schizophrenia pathophysiology on the other.
Specific aims are to identify:
1. What cognitive impairments characterize schizophrenia patients at first onset.
2. Whether functional capacities are predicted by these impairments at first onset.
3. What brain systems are involved.
4. How cognitive impairments, and their relationships with functional capacity and brain function, progress over 12 months.
A longitudinal design, targeting a total of 50 first onset schizophrenia patients and matched healthy controls.
Patient eligibility is a primary diagnosis of schizophrenia or schizophrenia spectrum disorder, according to DSM-IV criteria and confirmed by at least one psychiatrist independent of the study.
First onset status is defined by; first contact with a mental health service with psychotic symptoms, and testing occurs within 3 months of this contact. It is not possible in these clinical services to test patients prior to medication. However, since patients are first onset, medication will be limited in duration. For consistency, testing will occur once patients are on a maintenance dose.
Healthy controls will be screened for lack of psychiatric status, and matched to patients for age, sex, years of education, premorbid IQ and geographic region.
Exclusion criteria for both groups are: (1) treatment with antidepressants during past month, (2) meeting diagnostic criteria for primary depressive disorder, (3) illicit substance dependence, (4) mental retardation, (5) medical condition or disease that might interfere with the assessments (e.g. hearing impairment); (6) did not provide sign informed consent to take part.
Test-retest from Baseline to 6 months follow up testing:
(a) Baseline: Clinic status will be assessed to confirm diagnosis in patients, and healthy status in controls. Cognition will be assessed in both groups with the computerized touchscreen battery, IntegNeuro, and functional capacity with performance-based measures. EEG (for Gamma synchrony) and fMRI will be recorded to test the brain basis of cognition.
(b) 6 months follow up: Repeat testing of both groups with clinical status, cognitive performance, functional outcome using the same performance-based measures, and both EEG and fMRI recording.
Diagnosis: The Structured Clinical Interview for DSM disorder (SCID) will be used to confirm diagnosis in patients and screen for absence of psychiatric symptoms in healthy controls.
Symptoms: Symptoms will be rated using the Positive and Negative Syndrome Scales (PANSS), summed for positive and negative symptoms according to standard criteria.
Medication: Medication dose will be quantified in chlorpromazine equivalent units. Patients at study sites are typically receiving risperidone or quetiapine, routine atypical antipsychotics.
Functional capacity and outcome.
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