Major neurocognitive disorder is characterized by significant cognitive decline from a prior level of performance in one or more cognitive domains:
- Complex Attention: easily distracted in environments with competing stimuli (i.e., television and conversation), unable to perform mental math, difficulty holding new information in memory
- Executive Functions: unable to complete complex projects, can only focus on one task at a time, relies on others to organize and schedule activities of daily living
- Learning and Memory: repeats self within the same conversation, requires frequent reminders to keep on task
- Language: will use general phrase like, “that thing” and “that person”, unable to follow directions without repeating and rephrasing
- Perceptual-Motor: difficulties with previously familiar activities (i.e., driving), trouble navigating familiar environments
- Social Cognition: insensitivity to social modesty or politeness, makes decisions without personal regard for safety
The acquired cognitive decline is noted by both concern on part of the individual, a knowledgeable informant, or the clinician. The cognitive performance is also evaluated through an objective neuropsychological assessment, with performance compared with norms appropriate to the patient's age, educational attainment, and cultural background, to determine if the performance within the cognitive domains falls below the expected level. Major neurocognitive impairment performance typically falls 2 or more standard deviations below average (3rd percentile or below).