Modafinil improves the residual excessive daytime sleepiness (EDS) in patients who remain sleepy despite nCPAP therapy however, its effects on cognitive performance in this group of OSA patients have been equivocal. In the present study we examined the effects of a single modafinil dose on cognitive performance in newly diagnosed OSA patients, prior to the onset of nCPAP therapy.

Twelve unmedicated patients recently diagnosed with Obstructive Sleep Apnea (OSA) following polysomnography, entered into a double-blind, randomized, placebo-controlled crossover study using a single 200 mg dose of modafinil. The Cambridge Neuropsychological Test Automated Battery (CANTAB) and Visual Analogue Scales (VAS) were used.

Consistent with its alerting effects, modafinil increased VAS-rated alertness and improved visual and sustained attention (CANTAB Reaction Time Tests and RVIP). There was a trend for improvement in VAS-rated mood and anxiety. Modafinil improved problem solving performance (CANTAB Stockings of Cambridge) which was accompanied by prolonged thinking times. A similar pattern of improvement with improved recall coupled by prolonged response times was seen in the CANTAB Delayed Matching-To-Sample test of visual memory.

This modafinil-induced alteration in the speed-accuracy trade-off has been previously seen in healthy subjects and adults with ADHD and indicates that modafinil increases the ability to “reflect” on problems coupled with decreased impulsive responding. If these benefits are shown to be maintained with chronic administration, modafinil may have potential as an important therapy for OSA patients with residual EDS following nCPAP therapy.