Economic worries caused by the global downturn have brought more sleepless (doubled) nights to Taiwanese suffering from chronic insomnia in the last three years.
Nearly five million, or 21.8 percent of the island's 23 million people, have chronic insomnia, compared with 11.5 percent three years ago, according to the study from the Taiwan Society of Sleep Medicine.
The study also found that people with sleeping problems faced higher risks of developing heart disease, high blood pressure and diabetes, the society said in a statement.
The hike in sleeplessness was largely caused by unemployment, as the island's plunge into recession late last year made the job situation much more dire, it said.
Chronic insomnia is defined as having three sleepless night in a week with the symptoms lasting over one month.
Over 60 percent of the 4,000 people interviewed for the study also complained about having difficulties falling asleep within 30 minutes or waking up at nights.
Taiwan's October jobless rate was 5.96 percent, down from August's record high of 6.13 percent as the global financial crisis dealt a heavy blow to the island's export-dependent economy.