Cameras and motion sensors that track the way people move are giving new insights into mental illness like schizophrenia, bipolar disorder and attention-deficit/hyperactivity disorder (ADHD), say US researchers trialling the technology.

Early tests have already uncovered differences in the way patients with these conditions explore an unfamiliar room. Examining the way people move may also shed light on other aspects of the human condition.

Psychiatrist William Perry and colleagues at the University of California San Diego, US, were inspired by a technique called behavioural pattern monitoring used on mice. A camera is used to track the animal's movements as it explores a box with holes along its sides. Studying the pattern of movements has helped researchers understand the effects of drugs, or genetic modifications on brain chemistry.