Information from an EEG (electroencephalography) test could allow doctors to identify people at high risk of a particular mental disorder, such as schizophrenia. Scientists have found that a type of EEG brain wave is slightly different in people who have siblings with schizophrenia, compared with that seen in the general population. The researchers believe the information could be used to identify those at highest risk and pre-emptively treat them before they develop a full-blown mental disorder.