In Christopher Nolan's 2002 thriller "Insomnia," Al Pacino plays a detective who accidentally shoots his partner while trying to apprehend a suspect.

His guilt, plus the never-setting sun in Alaska (where he's investigating a case), rob him of sleep, even when he's past the point of exhaustion.

But you don't need nagging guilt and the midnight sun to suffer chronic insomnia.

Fully one-third of Americans have trouble falling or staying asleep. Luckily, there's a breakthrough treatment for chronic insomnia, called CBT-I (cognitive behavioral therapy for insomnia).

The idea is to identify and replace negative thoughts and behaviors that contribute to poor sleep with positive, sleep-inducing ones.

And it works! Studies have consistently shown that CBT-I can help people fall asleep more easily, sleep longer, and have a better quality of sleep.

And it gets you off those sleeping meds, which can trigger all kinds of weird behavior and moods.

You even can do CBT-I by using an app in the comfort of your own home. A few popular ones include GO!ToSleep, Sleepio, SHUTi, and Conquering Insomnia.

They all help you identify underlying issues, such as poor sleep habits, stress, or negative thoughts associated with bed, and then help you tackle these problems.

While you have to be committed to finding a solution to your insomnia for CBT-I to work, if you are, you may be enjoying sweet dreams within a few weeks.