1 - (SYM 65) Examining Relationships Between Sleep Preferences and Physical Activity with Suicide Risk Using Intensive Longitudinal Assessment

Emerging research suggests that particular sleep preferences and being physically active have important implications for understanding who is at risk for suicide. Eveningness chronotypes (biologically-based preferences towards later bed and rise times) are linked with increased risk for suicidal ideation (SI). In contrast, being more physically active has been linked with reduced SI. However, whether these factors may differentiate when patients are at risk for suicide during the day is unknown. We review preliminary results from two studies examining whether chronotype and patterns of physical activity differentiate momentary SI throughout the day in real-world settings.

In Study 1, 55 suicidal participants hospitalized on a psychiatric inpatient unit completed a baseline assessment of morningness-eveningness preferences and suicide risk history, followed by a 28-day ecological momentary assessment protocol measuring SI 5x/day. Logistic regression models and generalized linear mixed models were used to examine associations between chronotype, suicide attempt history, and SI over time. In Study 2, we describe pilot data about the physical activity of suicidal participants in relation to SI over a 28-day period collected as part of an ongoing research project, operationalizing physical activity using digital phenotyping information derived from smartphones.

We found that participants with eveningness preferences were more likely to have made a suicide attempt. There was also a significant Time x Chronotype interaction, such that participants with greater eveningness preferences were more likely to endorse SI over time vs. those with no preference or morningness (all ps< .05), and at particular times. Patterns of physical activity (i.e., daily/hourly steps and deviation from average) in relation to the presence and timing of SI are being analyzed and will be discussed.

These findings have important implications for understanding the role of chronotype and physical activity in suicide risk.  Specific chronotypes appear to indicate increased risk among suicidal patients, and may have relevance for identifying periods of time during the day when patients with particular phenotypes are more vulnerable to suicide risk. Whether physical activity patterns may be an important treatment consideration for patients at-risk for suicide will be discussed. These findings have important clinical and research implications, highlighting factors that may modulate the timing of SI, with potential implications for treatment of suicide risk.