Hypnagogic and hypnopompic hallucinations during amitriptyline treatment.

Four cases of hypnagogic or hypnopompic visual hallucinations in patients during amitriptyline treatment are reported. The hallucinations were clearly delineated, projected to the outer objective space and were for a short time experienced as real. The patients rapidly realized the unreality of the "sights", probably because they regained the full criticism and coherent thinking of an unpsychotic awake individual. There may be a relation between the effects of amitriptyline in brain, the changed pattern of sleep and the clinical recovery. Patients should be informed about the benign character of this type of hallucinatory phenomena so that treatment is not terminated at an undue time.