Researchers conducted a systematic review and meta-analysis of brain scan studies in people with schizophrenia who experience auditory verbal hallucinations—hearing voices that aren't there. They looked at patterns of intrinsic brain activity, which is the brain's baseline activity when not focused on a specific task. The analysis combined data from multiple existing studies, though the total number of participants wasn't reported.
The review found that hearing voices was consistently associated with increased activity in brain areas involved in hearing, language, motivation, and executive control. At the same time, it was linked to decreased activity in sensorimotor areas. The researchers also found that these brain activity patterns correlated with the locations of specific neurotransmitter systems in the brain, including cannabinoid, dopamine, and glutamate systems. Gene analysis suggested these brain regions are involved in neurodevelopment and regulating neural excitability.
This research provides a detailed map of brain activity patterns associated with hearing voices in schizophrenia. However, it's important to understand this is observational data from brain scans—it shows associations, not causes. The study didn't examine whether changing these brain patterns would reduce symptoms. No safety concerns were reported because this was a review of existing data, not a treatment trial.
Readers should take from this that scientists are working to better understand the brain basis of hallucinations in schizophrenia. This research helps build knowledge about which brain networks and chemical systems might be involved. While this could eventually inform more targeted approaches, it doesn't represent a current treatment breakthrough and doesn't change current clinical practice.