Study type: Epidemiological study

Receipt of Electroconvulsive Therapy and Subsequent Development of Amyotrophic Lateral Sclerosis: A Cohort Study epidem.

Published in: Bioelectromagnetics 2022; 43 (2): 81-89

Aim of study (acc. to author)

A cohort study was conducted in the USA to investigate the potential relationship between receipt of electroconvulsive therapy and the development of amyotrophic lateral sclerosis.

Further details

Exposure to extremely low frequency magnetic fields and electric shocks and working in “electrical occupations” have been studied since the 1980s as potential occupational risk factors for amyotrophic lateral sclerosis development. It has been suggested that exposure to electric shocks in these electrical occupations rather than exposure to extremely low frequency magnetic fields may be the causal factor for the development of amyotrophic lateral sclerosis. In occupational settings, it is difficult to separate exposure scenarios for electric shocks and extremely low frequency magnetic fields because they often occur together, making an independent assessment of the effects of the two exposures challenging. Electroconvulsive therapy, a common treatment for some psychiatric conditions, presents a setting where a well‐documented exposure occurs in a medical setting without substantial exposure to extremely low frequency magnetic fields. This provides a unique opportunity to examine the potential role of electric shocks in amyotrophic lateral sclerosis development in a controlled and well‐documented clinical environment without the confounding effect of extremely low frequency magnetic fields.

Endpoint/type of risk estimation

Exposure

Exposure groups

Group Description
Reference group 1 electroconvulsive therapy treatments: no
Group 2 electroconvulsive therapy treatments: yes
Reference group 3 number of electroconvulsive therapy treatments: 0
Group 4 number of electroconvulsive therapy treatments: 1 - 10
Group 5 number of electroconvulsive therapy treatments: > 11

Population

Study size

Type Value
Total 1,226,151
Statistical analysis method: ( adjustment: )

Results (acc. to author)

A total of 7,936 subjects (0.6%) of the cohort received electroconvulsive therapy. Overall, 1,246 subjects (0.1%) of the cohort were diagnosed with amyotrophic lateral sclerosis.
A moderately increased, statically non-significant hazard ratio (HR) for amyotrophic lateral sclerosis following electroconvulsive therapy was observed (HR 1.39; CI 0.69–2.80). A statistically significant increase in the hazard ratio of amyotrophic lateral sclerosis was observed among those who received more than 10 electroconvulsive therapy treatments (HR 2.24; CI 1.00–5.01) compared to those receiving no electroconvulsive therapy, with an even stronger association observed among subjects older than 65 years (HR 3.03; CI 1.13–8.10).
The authors concluded that the results provide weak support for the hypothesis that receipt of electroconvulsive therapy increases the risk of developing amyotrophic lateral sclerosis.

Study funded by

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