Coronary heart disease risk was used as a positive control, and primary outcomes included amyotrophic lateral sclerosis (ALS), Parkinson's disease (PD), and Alzheimer's disease (AD).<h4>Results</h4>PCSK9 inhibitors marginally reduced the risk of ALS (OR [95%] = 0.89 [0.77 to 1.00], p = 0.048), while they increased the risk of PD (OR [95%] = 1.417 [1.178 to 1.657], p = 0.004). Here, PCSK9 is linked to Parkinson disease.