Before revision: Thus, while Parkinson's disease, a neurodegenerative condition, causes executive dysfunction, a disorder such as attention-deficit/hyperactivity disorder is a classification given to a set of subjectively-determined symptoms implicating executive dysfunction – current models indicate that such clinical symptoms are caused by executive dysfunction.
After revision: Thus, while Parkinson's disease, a neurodegenerative condition, causes executive dysfunction, a disorder such as attention-deficit/hyperactivity disorder is a classification given to a set of subjectively-determined symptoms implicating executive dysfunction – models from the 1990s and 2000s indicate that such clinical symptoms are caused by executive dysfunction.