2026 ECNP Congress

PS03-3138

Environmental exposures and functional outcomes in bipolar disorder

Constanza Sommerhoff — M. Bort, G. Fico, T. Fernández, A. Montanari, L. Maitre, M. De Prisco, V. Oliva, E. Vieta, A. Murru · Hospital Clinic, Bipolar and Depressive Disorders Unit, Barcelona, Spain

2026 ECNP Congress

Introduction: A growing body of evidence links environment factors, including lifestyle choices, chemical pollution, light exposure, and the physical environment, to the risk and outcomes of bipolar disorder (BD) (1-3). However, evidence on the associations between environmental exposures and clinical outcomes in BD remains limited. This study examined the associations between environmental exposures, affective symptoms, sleep variability, and psychosocial functioning in a longitudinal sample of euthymic patients with BD.

Methods: This is a preliminary analysis from the BEGIN (Bipolar Exposome-Gene Interaction Naturalistic) study, a 12-month prospective naturalistic cohort with quarterly assessments conducted at the Bipolar and Depressive Disorders Unit, Hospital Clínic de Barcelona.

Environmental exposures, including perceived daytime and night-time noise, green/blue space exposure, and time spent outdoors, were assessed every 3 months by self-report. Sleep was continuously monitored using a commercial wrist-worn actigraphy device. Within-quarter variability was calculated for Total Sleep Time [TST], Sleep Efficiency [SE], Wake After Sleep Onset [WASO], and Composite Phase Deviation [CPD]. Affective symptoms were evaluated using the Montgomery–Åsberg Depression Rating Scale (MADRS) and Young Mania Rating Scale (YMRS), and functioning using the Functioning Assessment Short Test (FAST).

All continuous predictors were standardized (z-scores). Multiple linear mixed-effects models with random intercepts for participant were fitted to examine the associations between environmental exposures (predictors) and actigraphic variability metrics (TST, SE, WASO, CPD) and affective symptoms (MADRS and YMRS) as outcomes, adjusting for age, sex and season (Winter-Autumn vs. Spring-Summer). False Discovery rate (FDR) correction was applied.

A final multivariable mixed-effects model examined psychosocial functioning as the outcome, including environmental exposures, depressive symptoms (MADRS), and TST variability as predictors, adjusting for age, sex and season.

Results: Sixty-four participants (from 111 recruited between June 2023 and May 2025) met inclusion criteria based on actigraphic and environmental data completeness, contributing 127 relapse-free quarterly observations. Mean (SD) age of the sample was 50.39 (12.77) years, and 36 participants (56.2%) were female.

Higher perceived night-time noise was associated with greater depressive symptom severity (B = 1.56, p =0.046), greater mania symptom severity (B =0.53, p =0.018) and greater variability in TST (B = 7.31, p = 0.002). However, only the association with TST variability remained significant after FDR correction (p =0.017). In the final multivariable model, worse psychosocial functioning was independently associated with older age (p < 0.001), higher depressive symptom severity (p < 0.001), and greater TST variability (p = 0.010), while environmental exposures were not significantly associated with functioning.

Conclusion: Perceived night-time noise was associated with increased sleep variability in euthymic individuals with BD. However, environmental factors do not appear to have a direct association with psychosocial functioning, which was primarily related to depressive symptoms and total sleep time variability. Future studies should further investigate the longitudinal and potentially causal relationships between environmental exposures, sleep regulation, and clinical outcomes in BD.

References

  1. Carugno M, Palpella D, Ceresa A, Pesatori AC, Buoli M. Short-term air pollution exposure is associated with lower severity and mixed features of manic episodes in hospitalized bipolar patients: A cross-sectional study in Milan, Italy. Environ Res. 2021;196:110943.
  2. Chang HT, Wu CD, Wang JD, Chen PS, Su HJ. Residential green space structures are associated with a lower risk of bipolar disorder: A nationwide population-based study in Taiwan. Environ Pollut. 2021;283:115864.
  3. Radua J, De Prisco M, Oliva V, Fico G, Vieta E, Fusar-Poli P. Impact of air pollution and climate change on mental health outcomes: an umbrella review of global evidence. World Psychiatry. 2024;23(2):244-56.