A Dose-Response Study of Modafinil Effects on Cognition in Healthy Adults and in Schizophrenia Patients

Condition(s) targeted: Schizophrenia

Intervention: modafinil (M1, M2, M4) (Drug)

Phase: Phase 4

Status: Recruiting

Sponsored by: University of California, Davis

Official(s) and/or principal investigator(s):
Michael J. Minzenberg, MD, Principal Investigator, Affiliation: University of California, Davis

Overall contact:
Michael J Minzenberg, MD, Phone: 916-734-7174, Email: michael.minzenberg@ucdmc.ucdavis.edu

Patients with schizophrenia have problems in thinking, known as cognitive dysfunction. This includes many types of cognitive dysfunction, such as in attention, memory and language. These problems may explain why patients with schizophrenia think and act in unusual ways, and often have problems managing aspects of their lives that healthy adults take for granted. Unfortunately, the biochemical aspects of these dysfunctions are presently unknown, and it is not clear whether current psychiatric medications can improve these functions. A recent FDA-approved medication that may improve this function is modafinil. Studies in animals and healthy adults show that this medication can improve many of these cognitive functions. We plan to study the effects of modafinil on these cognitive processes, by giving various doses of this medication to patients before they perform tasks of these cognitive processes. We will also enroll healthy adults in these same procedures in order to determine how these effects are manifest in normal-range cognitive function. We predict that when patients or control participants receive modafinil, they will perform better on cognitive tests, and that these benefits will depend on the dose given.

Official title: A Dose-Response Study of Modafinil Effects on Cognition in Healthy Adults and in Schizophrenia Patients.

Study design: Treatment, Randomized, Double Blind (Subject, Caregiver, Investigator, Outcomes Assessor), Uncontrolled, Single Group Assignment, Efficacy Study

Primary outcome: cognitive performance

Secondary outcome:

blood pressure

heart rate

Detailed description: Schizophrenia is a disorder of cognition. The cognitive deficits of schizophrenia are present at the onset of the disorder, prior to medication exposure, are persistent during periods of remission, and are strongly related to functional outcome. These deficits prominently include prefrontal cortex-dependent functions. While existing medications effectively treat psychotic symptoms, they exhibit modest benefit at best for cognitive dysfunction. Studies of cognition in animal models indicate that the neurotransmitter systems that mediate many cognitive processes are not generally augmented by existing antipsychotic medications. Therefore, advances in the treatment of schizophrenia will require the study of agents with novel pharmacological profiles to establish their potential to remediate cognitive dysfunction.

This study will evaluate the effects of modafinil on the range of cognitive processes known to be disturbed in schizophrenia. Modafinil is an FDA-approved medication with a unique pharmacological profile and an increasing range of off-label indications. Its neurochemical effects in animal models include elevation of extracellular dopamine (DA), noradrenaline (NA) and glutamate in the neocortex. This profile is favorable for the enhancement of cognitive processes. These neurochemical effects also appear to be selective for cortical versus subcortical brain regions, suggesting that modafinil may have minimal effects on psychotic symptoms, or extrapyramidal, autonomic and hormonal side effects. In addition, it differs from amphetamine in structure, neurochemical profile and behavioral effects, with a lower risk of addictive or cerebrovascular effects. Recent studies in animal models, healthy adults and adults with psychiatric and neurological disorders indicate that modafinil improves prefrontal cognitive functions. This suggests that modafinil is a leading candidate for the treatment of cognitive dysfunction in schizophrenia. We aim to test modafinil effects on these processes in healthy adults, in order to evaluate modafinil effects on normal-range cognition, and then evaluate the remediation of deficits in these functions in individuals with schizophrenia. We will vary the dose within each participant to evaluate dose-response relationships, and directly compare cognition outcome measures for sensitivity to drug effects.

Minimum age: 18 Years. Maximum age: 54 Years. Gender(s): Both.

Criteria:

Inclusion Criteria:

- adults age 18-54

- diagnosis of schizophrenia or schizoaffective disorder, or healthy with no personal

or family history of mental illness

- able to provide informed consent

Exclusion Criteria:

- history of significant head injury or other neurological illness

- active psychiatric illness requiring significant acute care

- significant intellectual impairment (e. g. standardized full-scale IQ < 70)

- history of medical illness or treatment that is associated with significant increase

in risk from modafinil treatment (e. g. cardiac disease)

- significant active substance abuse

- active pregnancy

- active treatment with medications that have drug interactions with modafinil

Michael J Minzenberg, MD, Phone: 916-734-7174, Email: michael.minzenberg@ucdmc.ucdavis.edu

University of California, Davis School of Medicine, Sacramento, California 95817, United States; Recruiting
Michael J Minzenberg, MD, Principal Investigator

Starting date: May 2008
Ending date: July 2010
Last updated: February 18, 2009