Moderating role of functioning level on the association between suicidal ideation and delayed-onset post-traumatic stress disorder

This study aimed to investigate the relationship between suicidal ideation at baseline and the development of post-traumatic stress disorder (PTSD) in individuals who have experienced physical injuries, with a specific focus on how this relationship is moderated by the patient's functioning level. Participants were consecutively recruited from a trauma center and prospectively followed for two years. At baseline, suicidal ideation was assessed using the Brief Psychiatric Rating Scale, and functioning level was evaluated using the Social and Occupational Functioning Assessment Scale. During the follow-up, PTSD diagnosis was established using the Clinician-Administered PTSD Scale for DSM-5. Binary and multinomial logistic regression analyses were employed to examine the associations between suicidal ideation, functioning level, and PTSD. Of the 1014 participants analyzed, 114 (11.2%) developed PTSD, with early-onset observed in 79 (7.8%) and delayed-onset in 35 (3.5%) cases. Suicidal ideation at baseline was significantly associated with both early- and delayed-onset PTSD. Notably, higher functioning individuals with baseline suicidal ideation had an increased likelihood of developing delayed-onset PTSD, while this association was not significant in lower functioning individuals, with significant interaction terms. Additionally, suicidal ideation was a consistent predictor of early-onset PTSD across all functioning levels. The impact of baseline suicidal ideation on PTSD varies depending on the individual's functioning level, with higher functioning individuals being more vulnerable to delayed-onset PTSD. These findings underscore the importance of considering functional status in the assessment and intervention of PTSD following physical trauma. •Associations of suicidal ideation with PTSD over 2-years were evaluated.•Moderating effect of functioning level on the associations were investigated.•Suicidal ideation was a predictor of early-onset PTSD across all functioning levels.•Higher functioning individuals with suicidal ideation had higher delayed-onset PTSD.•Functioning level and suicidal ideation should be considered for predicting PTSD onset.