A pilot study of the prevalence of psychiatric disorders in PLS and ALS

Abstract

The prevalence of psychiatric disorders in primary lateral sclerosis (PLS) is currently unknown. In the present study, we compared the prevalence of psychiatric illness in patients with PLS and amyotrophic lateral sclerosis (ALS). We hypothesized that if the psychosocial stress of motor neuron disease predisposes patients to depressive disorders, patients with ALS (with a poorer prognosis and more disability than patients with PLS) should have a higher prevalence of depressive disorders than patients with PLS. We administered the gold standard of psychiatric assessment, the SCID, to 19 PLS and 13 ALS patients. We found a prevalence of current depressive disorders in PLS patients that was, by a non-significant trend, lower than that of ALS patients. The prevalence of current depressive disorders in the ALS patients was higher than previously reported and similar to that observed in non-neurological medical disorders. Other psychiatric disorders were rare. In conclusion, depressive disorders were the most commonly observed psychiatric disorders in both PLS and ALS. By a non-significant trend, the PLS patients had a lower current prevalence of depressive disorders than the ALS patients. These data are consistent with the hypothesis that the psychosocial stress of MND is a risk factor for depression.

Key words::

• PLS
• ALS
• psychiatric disorder
• depression
• major depressive disorder

Acknowledgements

We thank the staff of the Human Spinal Physiology Unit and the Clinical Center nurses for patient care, Tracy Peters for neuropsychological testing, and the patients and their families for their generous participation. This study was supported by the intramural program of The National Institutes of Health/The National Institute of Neurological Disorders and Stroke, an NIH/NINDS grant received by EDH, and the Litwin-Zucker Research Center for the Study of Alzheimer’s Disease and Memory Disorders.

Declaration of interest: None.