A multicenter study of sleep‐wake rhythm disorders: Therapeutic effects of vitamin B12, bright light therapy, chronotherapy and hypnotics

Abstract
One hundred and six subjects with primary sleep‐wake rhythm disorders [13 non‐24 hour sleep‐wake syndrome (non‐24), 76 delayed sleep phase syndrome (DSPS), 11 irregular sleep‐wake pattern (irregular) and six long sleepers] were treated with vitamin B12, bright light, chronotherapy and/or hypnotics. These therapies caused moderate or remarkable improvement in 32% of the non‐24, 42% of DSPS, 45% of irregular and 67% of long sleepers. A lack of adequate sleep, unpleasant feelings at waking and daytime drowsiness were also improved in DSPS.