About 21 million people globally struggle with schizophrenia and associated disabilities. Even with antipsychotic treatments, 30% of these patients continue to experience auditory verbal hallucinations, according to research published in the Journal of Psychiatric Research. This form of hallucination not only predicts suicide but also violence towards others in patients with schizophrenia, and needs to be addressed by clinicians.

Hallucination pathology

Heightened brain activity at the frontotemporal level is evident on functional MRI in patients experiencing auditory verbal hallucinations.

The frontotemporal regions play a role in perception and speech formation.

Another area of increased activity is the medial temporal lobe, which is devoted to verbal processing. Wernicke’s area may also contribute to auditory verbal hallucinations and is located at the left temporo-parietal junction.

Overall, there is abnormal connectivity among the auditory, verbal, and limbic (ie, memory) regions in schizophrenia patients experiencing auditory verbal hallucinations.

Chinese researchers published in Frontiers in Psychiatry charted a whole-brain diagram of dynamic functional connectivity (dFC) patterns based on functional MRI findings of 107 schizophrenia patients with auditory verbal hallucinations, 85 schizophrenia patients without these hallucinations, and 104 healthy participants.

Changes in dFC are usually present only in patients with schizophrenia and auditory verbal hallucinations.

“The present findings demonstrate that schizophrenia patients with [auditory verbal hallucinations] showed multiple abnormal dFC regions using auditory-related cortex and nucleus as seeds, particularly involving the occipital lobe, default mode network (DMN), and middle temporal lobe, implying that the different dFC patterns of auditory related areas could provide a neurological mechanism of [auditory verbal hallucinations] in schizophrenia,” the authors wrote.

Other possible causes

Multiple pathways have been linked to hallucinations, with trauma suggested as playing a key role. Sometimes—but not always—trauma plays a major role. (In other cases, it plays a minor role or no role.)

In some patients, hallucinations vary according to trauma input.

An overview published in Schizophrenia Bulletin suggested that hallucinated voices are intimately tied to other mental states associated with psychosis including perception, temporality, selfhood, reality, embodiment, and interpersonal experiences. Therefore, auditory verbal hallucinations shouldn’t be viewed as a separate phenomenon but contextualized with expressions of subjectivity.

Alternative treatments

There is a need for approaches other than antipsychotics to target these hallucinations.

The Schizophrenia Bulletin article highlighted the importance of digital tools in managing hallucinations. Such tools could include smartphones, the internet, wearable sensors, computer games, and virtual reality.

“It is envisaged that digital tools will contribute to improved self-management and service provision for people experiencing hallucinations.”

— Jardri, et al., Schizophrenia Bulletin

“Highlighted uses include smartphones to monitor and manage intermittently occurring hallucinations, therapeutic applications of audio and video media such as virtual and augmented reality, specific exercises targeting verbal aspects of hallucinations, and avatars to represent hallucinatory voices and to facilitate peer support,” the authors continued.

Barriers to using these digital tools to help treat auditory verbal hallucinations include limited access and patient resources, as well as finding funds for research and the crunching of big data sets.

Another emerging treatment for auditory verbal hallucinations is transcranial alternating current stimulation (tACS) focusing on network synchronisation between the prefrontal cortex and auditory cortex.

Researchers have shown that in patients with schizophrenia, 5 consecutive days of tACS restores alpha oscillations and results in better clinical outcomes. Weekly tACS sessions could be beneficial in patients with schizophrenia and auditory verbal hallucinations.

This story is contributed by Naveed Saleh and is a part of our Global Content Initiative, where we feature selected stories from our Global network which we believe would be most useful and informative to our doctor members.