'Stay awake' pill for treating bipolar depression?

Modafinil is a pill marketed for helping'alertness' and reducing 'excessive daytime sleepiness.' It is used for treating narcolepsy, and has off label uses in the treatment of ADHD.

From physorg:

A preliminary study of 85 patients with bipolar disorder shows that a drug used to treat patients with sleep disorders might also control the depressive symptoms associated with bipolar disorder. At least 44 percent of the participants in the study reported improved symptoms, a noteworthy improvement for a disorder in which new treatments are needed, according to the study’s author, Mark Frye, M.D., director of the Mayo Clinic Mood Disorders Clinic and Research Program.

Since there is a paucity of effective treatments for bipolar depression, anything that is clinically proven to be helpful would be very welcome.