Bayle's disease is an outdated concept that is often used in the context of bipolar disorder (BD). The term was coined by François Delay and Charles Dennem in 1861, who were French doctors and mental health researchers.
Bayle's disease is usually referred to as unilateral mood swings with elevated emotional states and the onset of sudden and prolonged periods of mania or hypomania. This disease is characterized by periods of manic mood followed by episodes of depression and vice versa. The pathology, as a rule, lasts for many years and can lead to significant disruption of the patient’s social and professional functioning. This is the main reason for the patient’s adaptation to society. It has now become generally accepted to use a different definition of this pathology. Bayley fever is a more modern designation for the condition, which is a short-lived paroxysmal agitation lasting only a few hours. From the moment of the patient’s previous relaxation until the onset of such an attack, 24-48 hours pass.