A new CAMH study showed the relationship between two chemicals released when people experienced stress - one released in the brain and the other in saliva - differs in people with schizophrenia.

Postdoctoral Research Fellow, Dr. Christin Schifani, said, "We found a disrupted stress response in people with schizophrenia, which did not occur in either healthy individuals or people at clinical high risk for developing psychosis." As most people with schizophrenia experience psychosis, identifying differences between people at high risk for psychosis and those with schizophrenia may shed light on how schizophrenia develops and ways to prevent its onset.

"The fact we see this disrupted stress response in people with schizophrenia, but not in people at high risk for psychosis, suggests an opportunity to intervene to prevent schizophrenia," said Dr. Romina Mizrahi, Clinician Scientist. In the study, the new insights come from examining two important chemical messengers - dopamine and cortisol - in people under stress. Dopamine is a neurotransmitter, a chemical that carries signals from one brain cell, or neuron, to another.

The researchers focused on dopamine released in the prefrontal cortex, the region at the front of the brain involved in complex functions, including regulating emotions. In healthy individuals, both dopamine and cortisol levels typically increase when people experience stress. Dr. Mizrahi added, "Our previous research had shown that people at high risk for psychosis and those experiencing the first episode of psychosis have abnormal, or increased dopamine release in response to stress in the striatum."

However, contrary to what they had expected, the researchers did not find significant differences in dopamine release in the prefrontal cortex among the three groups of participants. The full findings are present in the journal- Brain.