Research Areas

ML/NLP for Suicide Risk Prediction & Detection

Suicide is very hard to predict. In fact, despite decades of research, the ability to predict suicide remains only slightly better than chance. One reason for the lack of progress in this area is that many studies have examined isolated risk factors (e.g., depression) as predictors of suicide. My work leverages machine learning (ML) and natural language processing (NLP) to develop more precise, complex models for predicting and detecting suicide risk.

Given the meteoric rise in using ML/NLP to predict suicide, many questions have emerged about the clinical utility (or lack thereof) of these methods. To that end, my research has also considered how to best harness ML-based risk models in clinical settings.

Currently, my work at Crisis Text Line focuses on using NLP to better understand and help people in suicidal crisis using a dataset of more than 11 million text message conversations. You can read more about our work here.

Developing Interventions That Work

Most people who die by suicide do not have contact with a mental health provider in the year leading up to their death. How can we ensure people who need help are receiving it? My work in this area has focused on better understanding the reasons why people do not seek out mental health treatment, including stigma and other barriers (e.g., cost of treatment), identifying cost-effective treatments, and exploring novel intervention approaches.

I have focused on building user-friendly, technology-delivered interventions that people can access outside of traditional healthcare settings. In an ongoing grant from the National Institute of Mental Health (R34MH124973), my team is conducting a randomized controlled trial to test the effectiveness of a novel, game-like smartphone app to reduce suicide risk in adolescents after they leave psychiatric hospitalization.

The development of scalable, technology-based interventions like this will enable more people to receive potentially life-saving care.

Mental Disorders and Suicide Risk

Suicidal thoughts and behaviors frequently occur alongside other mental health concerns. The association between suicide risk and mental disorders is often bidirectional, with each influencing and exacerbating the other. Further, mental disorders share underlying mechanisms with suicidal behavior, such as emotion regulation difficulties and impaired cognitive control.

In my research, I have sought to better understand the overlap between suicide risk and mental disorders like PTSD and eating disorders. This has included work focused on how to best measure the presence of these disorders. I have also examined how transdiagnostic factors like sleep problems impact risk for suicide, harnessing technologies such as smartphones and wearable biosensors to study these phenomena in real-time. This work, funded by my recently completed Career Development award from the National Institute of Mental Health (K23MH120439), highlights sleep as a proximal, modifiable risk factor for suicide.

Testing Theories of Suicide

The rate of suicide in the U.S. been increasing over the past 20 years. To better understand how and why suicide happens, as well as how to prevent it, a number of theoretical models have been proposed. The Interpersonal Theory is one of the major theories of suicide (Joiner, 2005; Van Orden, Witte et al., 2010). This theory hypothesizes that suicide happens when someone possesses both suicidal desire and the capability to enact self-harm.

I conducted stringent tests of the theory in diverse samples (e.g., psychiatric inpatients, detained adolescent offenders, Army soldiers) during graduate school (working closely with my advisor Tracy Witte, who helped develop this theory) and in my postdoctoral fellowship. My work contributed to the knowledge base for what has arguably been the most influential modern theory of suicide.