Attention enhancing effects of methylphenidate are age-dependent

• We demonstrate that methylphenidate no longer improves attention in aged rats as it did when they were tested as adults.
• In addition, methylphenidate no longer enhances locomotor activity in aged rats as it did when they were tested as adults.
• We interpret this as possibly due to noradrenergic decline with aging.

The psychostimulant methylphenidate (MPH, Ritalin®) is used to treat a variety of cognitive disorders. MPH is also popular among healthy individuals, including the elderly, for its ability to focus attention and improve concentration, but these effects have not been shown to be comparable between aged and adult subjects. Thus, we tested whether MPH would improve performance in sustained attention in both adult and aged rats. In addition, we tested the impact of visual distraction on performance in this task and the ability of MPH to mitigate the effects of distraction. Adult (6–12 months) and aged (18–22 months) male Sprague–Dawley rats were given oral MPH, and their cognitive and motor abilities were tested. Results suggest that while MPH improves task performance in adults; there is no improvement in the aged animals. These outcomes suggest that the use of MPH for cognitive enhancement in elderly individuals may be ineffective.