That adds up to $31 billion in extra costs.
In the study in the Archives of General Psychiatry, 20 percent of participants had suffered from insomnia for at least 12 months. Scientists found more than 5 percent of those said they caused accidents or made errors at works that cost at least $500.
Accidents and errors include mishaps, such as making a mistake on an assembly line, getting into car accidents while on the job and miscalculations.
