There 's evidence that the hormone melatonin can be effective . It has occurred among nearly one in three Americans , group says . REM behavior disorder affects less than 1 % of the population , group says . Stress and lack of sleep can cause sleep disorders . Medications are available for more serious cases .
It has occurred among nearly one in three Americans , group says . REM behavior disorder affects less than 1 % of the population , group says . Stress and lack of sleep can cause sleep disorders . Medications are available for more serious cases .