Aggressive behavior can be defined as a noxious act purposefully aimed at a person, including the patient or an object , and can compose verbal (e.g., shouting, yelling, swearing, and inappropriate language) and nonverbal (e.g., kicking, scratching, hitting, spitting, biting, damaging property, and sexual behavior) acts.
Agitation can be defined as inappropriate verbal, vocal, or motor activity not judged to be motivated by the needs of or confusion in the patient .
From the definition, it is evident that behavior, which may be considered as a sign of agitation, is manifold and also may encompass, for example, aggressive behavior. We have already touched upon the issue of separating agitation and aggression into two distinct types of behaviors as suggested by some authors or whether aggression should be considered a type of agitation. In order to achieve more clinically relevant defining features, it may be necessary to revert back to observed behavior. Agitated behavior is usually always socially inappropriate. It may be aggressive behavior (toward self, others, or objects), appropriate behavior repeated at an unsuitable frequency (e.g., rocking/twisting head or body, tapping fingers/feet, opening/closing doors, wandering, folding clothes, and repeating questions, sounds, or words), or inappropriate behavior (e.g., undressing in public, overdressing, and sexual advances).
In addition to being subjectively unpleasant, irritability is an internal state associated with reduced control over temper and verbal or behavioral manifestations and may be present without any observable manifestations, i.e., simply as an unpleasant feeling in the patient. Examples of specific behavior include flashes of rage, sudden mood changes, impatience, being argumentative, and becoming easily angered, even due to insignificant problems.
Hyperactivity in dementia is most widely defined as a subsyndrome. Aalten et al. identified four behavioral subsyndromes in a dementia population, one of which was denoted as hyperactivity and comprised agitation, euphoria, disinhibition, irritability, and aberrant motor behavior . This finding has subsequently been confirmed in other populations .