Lousy day? Don’t try to think happy thoughts—just think fast. A new study shows that accelerated thinking can improve your mood. In six experiments, researchers at Princeton and Harvard universities made research participants think quickly by having them generate as many problem-solving ideas (even bad ones) as possible in 10 minutes, read a series of ideas on a computer screen at a brisk pace or watch an I Love Lucy video clip on fast-forward. Other participants performed similar tasks at a relaxed speed.

Results suggested that thinking fast made participants feel more elated, creative and, to a lesser degree, energetic and powerful. Activities that promote fast thinking, then, such as whipping through an easy crossword puzzle or brain-storming quickly about an idea, can boost energy and mood, says psychologist Emily Pronin, the study’s lead author.

Pronin notes that rapid-fire thinking can sometimes have negative consequences. For people with bipolar disorder, thoughts can race so quickly that the manic feeling becomes aversive. And based on their own and others’ research, Pronin and a colleague propose in another recent article that although fast and varied thinking causes elation, fast but repetitive thoughts can instead trigger anxiety. (They further suggest that slow, varied thinking leads to the kind of calm, peaceful happiness associated with mindfulness meditation, whereas slow, repetitive thinking tends to sap energy and spur depressive thoughts.)

It is unclear why thought speed affects mood, but Pronin and her colleagues theorize that our own expectations may be part of the equation. In earlier research, they found that people generally believe fast thinking is a sign of a good mood. This lay belief may lead us to instinctively infer that if we are thinking quickly we must be happy. In addition, they suggest, thinking quickly may unleash the brain’s novelty-loving dopamine system, which is involved in sensations of pleasure and reward.

The kind of rush that a person gets from rapid-fire thinking may be transient, but “these little bursts of positive emotion add up,” says psychologist Sonja Lyubomirsky of the University of California, Riverside. Studies have demonstrated that happiness yields myriad benefits, including greater productivity, stronger social support and improved immune function, she explains, adding that “even brief periods of heightened mood can lead to upward spirals.”

Note: This article was originally printed with the title, "Think Fast".