ALS Risk Factors Linked to Certain Antidepressants, Anti-Anxiety Drugs: Study

Patients taking at least two psychiatric drugs may face a greater risk of developing ALS than other individuals, even if the medications were prescribed more than five years earlier.

New research suggests that certain kinds of psychiatric medications can increase an individual’s chance of developing amyotrophic lateral sclerosis (ALS), also known as “Lou Gehrig’s Disease”, with some users experiencing a sixfold higher risk.

The findings were published in JAMA Network Open on June 4, building on prior research linking ALS to the use of various psychiatric drugs, including antidepressants, anti-anxiety medications (anxiolytics), and hypnotics or sedatives commonly prescribed for sleep or stress-related conditions. 

These medications are often used to treat depression, anxiety disorders, PTSD and insomnia, and include drugs such as SSRIs, SNRIs, tricyclic antidepressants, benzodiazepines (e.g., Valium, Xanax, lorazepam), gabapentin, risperidone and barbiturates.

ALS is a progressive neurodegenerative condition that destroys motor neurons in the brain and spinal cord. These neurons control vital muscle movements, including speech, swallowing and breathing. As the disease progresses, individuals experience increasing paralysis, and most cases are fatal. There is currently no cure for ALS.

In the new study, researchers reviewed the ALS risk factors by analyzing medical data from more than 1,000 individuals diagnosed with the condition between January 2015 and July 2023, using records from the Swedish Motor Neuron Disease Quality Registry. 

Led by Dr. Charilaos Chourpiliadis of the Karolinska Institutet in Stockholm, Sweden, the research team matched each ALS patient by age and sex with at least five individuals who were not diagnosed with ALS, along with their siblings and spouses. Patients were followed for an average of 1.33 years.

Using conditional logistic regression models, the researchers found that ALS patients were 6.1 times more likely to have been prescribed two or more psychiatric medications within a year prior to diagnosis, compared to individuals without ALS. 

The increased risk remained significant even years earlier. Patients had a 1.6 times greater risk of having taken psychiatric drugs within one to five years before diagnosis, and a 1.2 times greater risk more than five years before diagnosis.

“In this case-control study, prescribed use of anxiolytics, hypnotics and sedatives, or antidepressants was associated with a higher subsequent risk of ALS,” Chourpiliadis said. “Prediagnostic use of such medications was also associated with a poor prognosis after ALS diagnosis.”

ALS Diagnosis Risk Factors

A number of studies have linked ALS to a variety of external factors in recent years. In 2023, a Swedish research team showed that the use of certain pesticides can lead to heart disease, Parkinson’s disease and ALS.

These findings elaborated on a 2016 study from the University of Michigan, which showed that military service and pesticide exposure could be linked to an increased risk of ALS.

In addition, Danish researchers linked diesel exhaust to an increased risk of ALS in men in 2018, while a study from 2015 showed a relationship between on-the-job formaldehyde exposure and ALS.