The use of sleep deprivation must be used with caution in BD. Colombo et al. (1999) found that in a sample of 206 people with bipolar depression treated with three cycles of sleep deprivation, alone or in combination with heterogeneous medications, that there was a 4.85% switch rate into mania and a 5.83% switch rate into hypomania, which were comparable with those observed with antidepressant drug treatments.