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Biomedical subjects

M D Drennan

Publications and source records attributed to M D Drennan.

2 recordsLinked to original sources
PubMed1991

The effects of depression and age on the Horne-Ostberg morningness-eveningness score.

Effects of depression and age on the Horne-Ostberg morningness-eveningness scale in human volunteers were assessed. Thirty-nine healthy outpatients with current DSM-IIIR depression, free of recent substance abuse or confounding medications, were compared to 39 age- and sex-matched controls. Patients reported greater 'eveningness' than controls (P = 0.014, Wilcoxon signed-ranks test). There was multimodality in the distribution of Horne-Ostberg scale scores in the depressed group, but a normal distribution in controls. Pearson's correlation of age vs. Horne-Ostberg score was positive (r = 0.42-0.55). Depression and age influence the Horne-Ostberg score. Potential multimodality of circadian phase in the depressed group deserves further study.

Adult↗
PubMed1991

Potassium affects actigraph-identified sleep.

The present study examines the effects of potassium supplementation on sleep quality and phase, as indirectly inferred from wrist actigraphy and sleep logs, in normal young males on a low-potassium diet. A randomized, double-blind, placebo-controlled, counterbalanced crossover design compared 1 wk of oral potassium chloride supplements (96 meq/day) to 1 wk of identical placebo capsules. Outcome measures were taken from sleep logs and wrist actigraphy. Sleep was indirectly inferred from wrist-actigraph data using a computer algorithm. Potassium supplementation significantly delayed sleep-log-identified Bedtime (p less than 0.001). Potassium reduced Sleeping Interval for both sleep-log (p less than 0.01) and wrist-actigraph (p less than 0.1) data. Potassium significantly increased actigraphic Sleep Efficiency (p less than 0.05) due to a reduction in actigraphic Wake after Sleep Onset (WASO) (p less than 0.05). No effect of potassium on actigraphic sleep phase was observed. Side effects were minimal and not significantly different between treatment conditions. The results may indicate an improvement in sleep consolidation with potassium supplementation. Further studies using standard polysomnography are required to define potassium's effects on human sleep.

Adult↗