People with schizophrenia experience symptoms such as delusions, hallucinations and disturbances in thinking, and often become fearful and withdrawn. Determining the cause of schizophrenia is difficult due to the heterogeneous nature and complexity of the disorder. Current theories suggest abnormal development in brain regions that regulate movement, emotion, speech, behaviour, learning and memory may cause schizophrenia. John Howland is studying whether altered interactions involving dopamine and glutamate — chemicals that carry messages between brain cells — can result in behaviour that is consistent with schizophrenia. This research could provide support for theories that developmental abnormalities cause schizophrenia.