Akiskal, H. S., Djenderedjian, A. H., Rosenthal, R. H. et al.: Cyclothymic disorder: Validating criteria for inclusion in the bipolar affective group. Am. J. Psychiatry, 134: 1227-1233, 1977.
Akiskal, H. S., Bitar, A. H., Puzantian, V. R. et al.: The nosological status of neurotic depression: a prospective 3-4 year follow-up examination in the light of the primary-secondary and the unipolar-bipolar dichotomies. Arch. Gen. Psychiatry, 35: 756-766, 1978.
Akiskal, H. S.: The bipolar spectrum: New concepts in classification and diagnosis. In: Psychiatry Update: The American Psychiatric Association Annual Review (ed. by Grinspoon, L.), pp. 271-292, Washington, D. C., American Psychiatric Press, 1983.
Akiskal, H. S., Mallya, G.: Criteria for the “soft” bipolar spectrum: treatment implications. Psychopharmacol. Bull., 23: 68-73, 1987.
Akiskal, H. S., Cassano, G. B., Musetti, L. et al.: Psychopathology, temperament and past course in primary major depressions. 1. Review of evidence for a bipolar spectrum. Psychopathology, 22: 268-277, 1989.