Emory researchers use voice analysis to study psychedelic therapy

Understanding and treating depression is complex, particularly when capturing the daily experiences of those living with it. Researchers are now exploring a new approach: using the human voice to gain deeper insight into how people process, express and recover from depression, thanks to newly developed technology.

Fabla, a voice diary app for clinical research developed at Emory University, is central to a study on psilocybin’s effects in individuals with major depressive disorder. The app prompts participants to record daily spoken reflections before and after undergoing treatment, offering researchers a window into how their language and emotional state evolve in response to 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.”

Fabla is the first mobile app enabling researchers to securely collect participants’ speech biomarkers throughout their daily life. Speech biomarkers are subtle patterns in a person’s voice, such as tone, pitch and word choice, that can provide insight into their mental and emotional state. By analyzing these markers, researchers can track changes in mood, cognition and overall well-being over time.

Understanding psilocybin’s effectiveness

The OPTIMIZE study (An Investigation of Strategies to Understand and Optimize the Antidepressant Effects of Psilocybin) is a clinical trial examining whether adding mild, non-invasive electrical stimulation of the vagus nerve might enhance the antidepressant benefits of psilocybin. This is a Phase 2 study of psilocybin, meaning researchers are moving beyond early safety tests and focusing on how well psilocybin works as a treatment for depression.

Fabla will be essential for monitoring how participants’ speech, emotions, and social interactions change before and after treatment. Participants receive personalized questions via the app, allowing researchers to track individual speech patterns over time. This approach not only helps compare each person’s speech to their own baseline but also provides insight into how participants’ experiences change in response to treatment by examining how their language evolves throughout the study.

Recruitment begins in April 2025 for 141 adults experiencing a depressive episode of at least 60 days. All participants receive a single 25 mg dose of psilocybin under controlled conditions, accompanied by preparation sessions and post-dosing integration sessions with trained facilitators. Participants will be monitored over time to measure changes in depression severity, anxiety, well-being, social behavior and overall quality of life.

“The OPTIMIZE study is about more than just testing psilocybin’s effects. It’s about understanding how this treatment changes the way people think, feel, and engage with the world,” says Roman Palitsky, PhD, director of research projects for Emory Spiritual Health and the Emory site principal investigator for the OPTIMIZE study. “Fabla captures those changes in real time, offering a deeper, more nuanced view of the healing process than traditional surveys or laboratory methods.”

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