Antidepressant medications, neuroleptics, and prominent eye movements during NREM sleep

Eye movements during stage 2, 3, and 4 sleep have been associated with the use of several selective serotonin reuptake inhibitor (SSRI) medications. This activity has been postulated to be a serotonin effect. The authors identified all cases of nonrapid eye movement (NREM) eye movements observed over a 36-month period in an accredited hospital-based sleep center and then correlated the findings with the patient's medications. The polysomnogram (PSG) studies of 2,959 consecutive adults were evaluated prospectively to identify all patients with atypical eye movements which occurred during NREM sleep. Standard recording, staging and arousal scoring methods were used. The use of antidepressants and neuroleptic medications was recorded for each patient. Eye movements in NREM sleep were detected in 94 PSGs. Of these, 73 patients (78%) were taking a SSRI at the time of the study, and 6 (6%) had taken a SSRI in the past. Thirty-six percent of patients (73 of 201) taking a SSRI had abnormal NREM eye movements on PSG. Other classes of antidepressants, neuroleptics, and benzodiazepines showed a much lower incidence of NREM eye movements. Mirtazapine was rarely related to NREM eye movements. Clonazepam and zolpidem were not associated with atypical eye movements unless used in combination with SSRI medications. Selective serotonin reuptake inhibitors was associated with atypical NREM eye movements, even when the medication had been discontinued months to years before the PSG. Atypical NREM eye movements appear to be related primarily to serotonin and less prominently to dopaminergic medication effects.