New App Measures Psilocybin Therapy Success Using Voice Analysis

Treating depression isn’t easy— especially when it comes to truly understanding what life is really like, day to day, for those living with it. But researchers have a new tool up their sleeve: voice analysis, to better understand how people experience, express, and recover from depression, using some impressive new tech to help.

Enter Fabla, a voice diary app created at Emory University for clinical research. Though very new, it could end up playing a key role in a study exploring how psilocybin affects people with major depressive disorder. Participants use the app to record short spoken reflections each day, both before and after their treatment. These voice notes give researchers a unique glimpse into how language and emotional tone shift over time with the help of psilocybin-assisted therapy.

“Speech carries information we don’t always consciously recognize,” says Deanna Kaplan, PhD, director of the Human Experience and Ambulatory Technologies (HEAT) Lab at Emory University School of Medicine and creator of Fabla. “By allowing researchers and clinicians to ask questions participants answer aloud, we can capture markers of mental health contained in speech that reveal more than written words alone.”

The First App Of Its Kind

Fabla is the first mobile app designed to let researchers securely gather speech biomarkers from participants as they go about their daily lives. These biomarkers are subtle vocal patterns — like tone, pitch, and word choice — that can reveal a lot about someone’s mental and emotional well-being. By studying these patterns, researchers can monitor shifts in mood, thinking, and overall health over time.

There’s growing evidence that depression can influence how people speak. Those experiencing depression tend to use more self-focused words, like “I,” “me,” and “mine,” and fewer collective terms such as “we” and “us.” Their speech may also sound more flat or monotone. Research shows that tracking these kinds of speech cues can help experts gauge the severity of someone’s depression and how they’re responding to treatment.

Clinical Trials to Begin Soon

Recruitment for the “OPTIMIZE” study, (short for An Investigation of Strategies to Understand and Optimize the Antidepressant Effects of Psilocybin) is set to kick off next month. The clinical trial will take place at a healthcare center in Colorado, with plans to enroll 141 participants. Each person will use the Fabla app for two weeks leading up to their therapy sessions and continue using it for six weeks afterward.

Fabla will play a key role in tracking changes in speech, emotion, and social behavior throughout the course of treatment. The app sends each participant personalized prompts, helping researchers monitor individual speech patterns over time. This lets them compare each person’s language to their own baseline, giving valuable insight into how their experiences shift in response to treatment.

A ‘Deeply Personal’ Window

“Rather than simply asking if someone feels ‘better,’ we’re examining how their internal dialogue changes. Fabla lets participants give us a window into the deeply personal nature of a psychedelic experience,” said Fabla creator Deanna Kaplan in an announcement from Emory.

“We know psilocybin can create profound shifts in perception and emotional processing, but understanding how those changes unfold over time, and in daily life, is critical,” explained Roman Palitsky. “Fabla allows us to listen — literally — to how participants express themselves before and after treatment. Are they speaking with more hope? Do they have more concentration on others? By studying these shifts in language, we can better understand how psilocybin can help recovery from depression.”

Outside of Emory, Imperial College London is currently the only other major research institution to include speech analysis in a psilocybin study on depression. Their findings were published in the Journal of Affective Disorders back in 2018.

Psychedelics Are a Growing Field of Study

Emory itself launched its Center for Psychedelics and Spirituality in 2022 in response to the renewed global interest in entheogenic substances. Based within the university’s Brain Health Center, the center focuses on the intersection of science and spirituality and houses a growing body of research on plant medicines and related topics.

“Foremost in our work is to advance ethical standards, usher cultural epistemology, be responsible to a psychospiritual model, and to make accessible healing pathways to diverse populations,” the university stated.

In October, Emory also released a podcast episode spotlighting the OPTIMIZE study, featuring principal investigator Roman Palitsky.“Scientific interest in psychedelics as possible therapeutics began in the early 20th century but waned once the government classified substances like LSD and MDMA as illegal and highly restricted,” said the Rollins School of Public Health, which produced the episode.

“Today, psychedelics are gaining traction again due to research that highlights their potential therapeutic benefits for mental health conditions like depression and PTSD.”