aim  To review the recent literature on autism spectrum disorders and summarise the current state of our knowledge.
method  The literature published over the last ten years was reviewed with the help of Medline, using as key words autism, PDD and Asperger.
results and conclusion  According to the model for developmental psychopathology (developed by Morton & Frith in 1995) autism spectrum disorders can be regarded as the clinical expressions of a heterogeneous neurobiological disorder that affects the functioning of the brain. The conditions are partly hereditary and partly acquired and in general are characterised by neurocognitive dysfunctioning. However, the neurocognitive evidence does not support this hypothesis since the neurocognitive dysfuncions in individuals with autism spectrum disorders are far more heterogeneous that has been supposed hitherto.