Insomnia symptoms are associated with impaired resilience in bipolar disorder: potential links with early life stressors may affect mood features and suicidal risk

Aim: The study aimed to investigate resilience and its association with early exposure to stressful events on the clinical manifestations of bipolar disorders (BDs), such as severity of mood symptoms, suicidal ideation and behaviors focusing on the possible role of insomnia symptoms. Method: A sample of 188 adult participants with BD of type I or II were assessed during depressed phase using the Structural Clinical Interview for DSM-5 (SCID-5), the Beck Depression Inventory-II (BDI-II), the Young Mania Rating Scale (YMRS), the Early Trauma Inventory Self Report-Short Form (ETISR-SF), Resilience Scale for Adults (RSA), the Insomnia Severity Index (ISI) and the Scale for Suicide Ideation (SSI). Participants with or without clinically significant insomnia were compared and we carried out correlations, regression and mediation analyses. Results: Participants with insomnia showed a greater severity of depressive symptoms as well as of suicidal risk, early life stressors and lower level of resilience. Insomnia symptoms mediated the association between early life stress and low resilience, between low resilience in planning future and depressive symptoms (Z = 2.17, p = 0.029) and low resilience and suicidal risk (Z = 3.05, p = 0.0002) Conclusion: Insomnia may be related to the severity of BDs, to higher early life stressors and lower level of resilience. Assessing and targeting insomnia symptoms may potentially promote resilience in BDs in response to early life stressful events. These results should be interpreted in light of several limitations including the cross-sectional design affecting causal interpretations.