Their sense of anxiety increases if they are unable to move about. While the above tardive syndromes are characterized by excessive movements, individuals may also experience a drug-induced parkinsonism which appears clinically like Parkinson's disease. With drug-induced parkinsonism, there is an absence of movement. Individuals have slow movements with rigid or stiff muscles and tremor. When walking, a shuffling gait is present with a stooped posture and diminished arm swing.
Facial expression is blunted causing a very solemn appearance.
Of all the tardive syndromes, drug-induced parkinsonism is the most reversible. It resolves after the medication is stopped, but this may take up to 18 months. The criteria for diagnosing a tardive syndrome can vary but is generally agreed to be exposure of an individual to a dopamine receptor blocking agent within 6 months of onset of symptoms which persist at least 1 month after stopping the offending drug. The longer the drug is taken, the greater the chance of developing a tardive syndrome. Once the symptoms are noticed, the best course of action is to stop the medication if possible.