Direct answer: Based on recent discussions and coverage of Zero Day, the character George Mullen’s cognitive difficulties are depicted as symptoms that mimic dementia in early reviews, but several outlets push back on diagnosing him with dementia explicitly, suggesting alternative explanations such as a neurological weapon or other plot devices. The consensus among multiple articles is that the show leverages memory lapses and perceptual distortions to drive the drama, while some creators or interviews imply a more nuanced or contested explanation rather than a straightforward dementia diagnosis. If you’d like, I can pull up specific article quotes and summarize each viewpoint with citations.