Electroencephalography of patients on long-term treatment in a lithium clinic

Abstract

Seventy-six patients attending the lithium units in a Swedish psychiatric clinic were investigated with electroencephalography. The patients, 50 women and 26 men, were between 27 and 84 years of age and had been on medication for periods ranging from 1 to 20 years. The serum lithium level varied between 0.2 and 1.1 mmol/l. Thirty-nine patients had bipolar and 19 had unipolar affective psychosis (ICD-9). Fifteen of the 19 patients with unipolar disease were diagnosed as melancholic. Twenty-eight patients (37%) had EEG changes consisting of an episodic abnormality of generalized slow waves. A tendency towards the higher serum lithium values, 0.7–0.9 mmol/l, was seen among these patients. Abnormal EEGs were over-represented among the patients with melancholy (60%). Only 1 of the 10 patients without the common lithium-induced side effects had an abnormal EEG. The EEG abnormality did not seem to influence the patients' behaviour or social status to any major extent.

Key Words:

• Affective disorders
• Electroencephalography
• Lithium
• Outpatient clinics

Additional information

Notes on contributors

Peter Persson

Joyce Laing works in the Department of Child and Family Psychiatry, Playfield House, Cupar, Fife, and is a Consultant Art Therapist to Psychiatric Hospitals and Prisons and Chairwoman of the Scottish Society of Art and Psychology.