Sleep preceding the onset of a manic episode.

@article{Knowles1979SleepPT,
  title={Sleep preceding the onset of a manic episode.},
  author={J. B. Knowles and J. W. F. Waldron and John Cairns},
  journal={Biological psychiatry},
  year={1979},
  volume={14 4},
  pages={671-5}
}