Artificial intelligence (AI) could be a useful tool in mental health treatment, according to a new study.

The study, which was the first to test an AI voice-based virtual coach for behavioural therapy, found changes in patients' brain activity along with improved depression and anxiety symptoms after using Lumen -- an AI voice assistant that delivered a form of psychotherapy.

The results, published in the journal Translational Psychiatry, offer encouraging evidence that virtual therapy can play a role in filling the gaps in mental health care, where waitlists and disparities in access are often hurdles that patients, particularly from vulnerable communities, must overcome to receive treatment.

"We've had an incredible explosion of need, especially in the wake of COVID, with soaring rates of anxiety and depression and not enough practitioners," said Dr. Olusola A. Ajilore, professor of psychiatry at the University of Illinois Chicago (UIC).

"This kind of technology may serve as a bridge. It's not meant to be a replacement for traditional therapy, but it may be an important stop-gap before somebody can seek treatment," Ajilore added.

The researchers recruited over 60 patients for the clinical study exploring the application's effect on mild-to-moderate depression and anxiety symptoms, and activity in brain areas previously shown to be associated with the benefits of problem-solving therapy.

Two-thirds of the patients used Lumen on a study-provided iPad for eight problem-solving therapy sessions, with the rest serving as a "waitlist" control receiving no intervention.

After the intervention, study participants using the Lumen app showed decreased scores for depression, anxiety and psychological distress compared with the control group.

The Lumen group also showed improvements in problem-solving skills that correlated with increased activity in the dorsolateral prefrontal cortex, a brain area associated with cognitive control. Promising results for women and underrepresented populations also were found.

"It's about changing the way people think about problems and how to address them, and not being emotionally overwhelmed," said Dr. Jun Ma, Professor of Medicine at UIC.

"It's a pragmatic and patient-driven behaviour therapy that's well established, which makes it a good fit for delivery using voice-based technology," Ma added.