William Cullen proposed that neurosis depends on a general pathological state of the nervous system rather than a local pathological state of any organ. This definition appears to have predicted the fate of this concept, which is now in a process of evanescence. However, there is currently a need for a compensatory concept, which may be provided by neurodevelopmental disorder. In autism spectrum disorder (ASD) and attention-deficit/hyperactivity disorder (ADHD), anxiety is an essential trait rather than a comorbidity. Neurosis has traditionally been conceptualized as a developmental state of the mind, with anxiety as an essential feature. Anxiety typically arises from the memory of trauma, and exposure to trauma during childhood tends to generate some neurodevelopmental disorders. Thus, neurosis and neurodevelopmental disorders share anxiety as an essential feature. If we consider neurodevelopmental disorders as neuroses with some lifetime variance, neuroses can be considered as neurodevelopmental disorders that involve various forms of anxiety according to development. Assuming that the two concepts have a common basis in "developmental anxiety", neurotic disorders and neurodevelopmental disorders may constitute an encompassing group of diseases. Based on this grouping, the distinguishing features of psychosis should also be re-evaluated from a new perspective.
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