However, there is confusion as to the nature of the continuum or continua under discussion. According to the author, commentators on this topic do not often distinguish between the variability and severity of the phenomena themselves, within or between individuals, versus the distribution of symptoms or risk factors in a population
With our current knowledge, Alzheimer's dementia is a condition that can be called a disease as its pathophysiology and tentative causes have been elucidated and proven. In contrast, schizophrenia still does not qualify as a disease. [2]