People are more likely to commit suicide in the middle of the night, according to new research from the University of Pennsylvania.

It's a bad thing to be awake when reason is asleep, says Penn psychiatrist Michael Perlis.

"In the middle of the night, you're not thinking clearly, you're not making good judgments, and everything seems to be just catastrophic, he said.

For individuals at risk for suicide because of depression and other mental illness, it this turns out to be a toxic mix, said Perlis. He studied more than 30,000 completed suicides, using data from the National Violent Death Reporting System, and found that once the data is adjusted for how many people are awake at any given hour, a strong peak emerges around 2 a.m.

The findings mean new approaches for suicide prevention.

"If we can get to the people who are at risk to make sure they sleep through the night, there is the promise of making sure that a lot of people who are vulnerable are less vulnerable," Perlis said.

Suicide prevention experts add that the findings also point to a need for the availability of more mental health resources, such as ensuring hotlines have adequate staffing, during the night.