Neuropsychiatric symptoms form part of the clinical picture of Alzheimer's disease (AD) and other dementias. Irrespective of the severity of the disease, the most frequently encountered symptom is apathy. Apathy is increasingly diagnosed in patients with neurological and psychiatric conditions. Apathy is a disorder of motivation, defined as "the direction, intensity and persistence of goal-directed behaviour". Most of the current descriptions acknowledge this point and consider apathy in terms of a lack of goal-directed behaviour, cognition or emotion. The classical neuropsychiatric symptom assessments are subjective structured interview-based, using input from the caregiver and/or the patient. New technologies are likely to provide us with a more objective measure. An example is ambulatory actigraphy, consisting of a piezoelectric accelerometer designed to record arm movement in three dimensions.