Background: Apart from ageing, the factors associated with vulnerability to the emergence of tardive dyskinesia are poorly defined.
Method: Risk factors associated with the presence of a chronic choreic or dystonic disorder were assessed in a cross-sectional comparison of anamnestic and clinical data in a homogeneous group of 64 young psychotic patients (under 40 years of age) on chronic low to moderate doses of neuroleptics.
Results: Dyskinetic subjects presented more indirect indicators of occult brain damage, such as a perinatal event or traumatic brain injuries in infancy and early childhood; neurological examination showed more anomalies in dyskinetic patients than in nondyskinetics, with a higher prevalence of facial release reflexes.
Conclusion: These data may support the hypothesis that occult acquired brain damage is important in the genesis of this 'drug-induced' disorder.