Effects of modafinil and r-modafinil on brain stimulation reward thresholds : implications for their use in the treatment of psychostimulant dependence

Abstract EN

Background.

Modafinil and its enantiomer R-modafinil are approved for the treatment of various sleep disorders, and may also be efficacious in the treatment of psychostimulant abuse.

However, the ability of modafinil and R-modafinil to alter brain reward function has not yet been assessed.

Purpose.

This study assessed the effects of modafinil and R-modafinil on brain reward function using the intracranial self-stimulation (ICSS) paradigm.

Study design.

Male Sprague- Dawley rats were trained to respond for ICSS using current-intensity threshold determination procedures.

Changes in ICSS thresholds were then assessed following administration of modafinil and R-modafinil (50, 100, and 150 mg/kg), or cocaine (2.5 mg/kg–20 mg/kg) as a positive control.

Results.

ICSS thresholds were reduced by modafinil at the 150 mg/kg dose, as well as by cocaine at the 10mg/kg and 20mg/kg doses.

R-modafinil only produced nonsignificant trends towards reducing ICSS thresholds.

Conclusion.

Modafinil and R-modafinil have limited effects on brain reward function in otherwise drug-na¨ıve subjects.

Additional assessments of these effects in the context of psychostimulant dependence are needed