Advancing models of PTSD–AUD comorbidity: protocol for a multimethod framework using genetics and ecological momentary assessment

<b>Background:</b> Posttraumatic stress disorder (PTSD) and alcohol use disorder (AUD), which are moderately heritable, frequently co-occur and contribute to significant public health burdens, particularly among economically disadvantaged urban communities. There are noted sex differences in PTSD and AUD outcomes, with evidence suggesting women have heightened susceptibility to stress-related alcohol use. Preliminary PTSD-AUD ecological momentary assessment (EMA) findings support bidirectional associations across clinical outcomes. However, no studies to date have used PTSD-AUD comorbidity models as organizing frameworks to examine the temporal ordering and stability of within-person symptom dynamics underlying the maintenance or exacerbation of PTSD and AUD symptoms, including bidirectional and shared-liability processes. Moreover, this type of work has not been conducted in high-risk, socioeconomically disadvantaged Black individuals from urban communities or within a genetically informed framework that facilitates adjustment for shared genetic liability.<b>Method:</b> The current study will recruit 464 self-identified Black adults who report a history of at least one traumatic event, current PTSD symptoms, and a recent binge or hazardous drinking from a larger trauma-exposed urban cohort. Through intensive, repeated EMA over six months, this study will use established PTSD-AUD comorbidity models as organizing frameworks to characterize sex-specific, within-person symptom dynamics. We will examine the temporal stability of these dynamics and explore how social drivers of health and unique and shared genetic risk for PTSD and AUD are associated with the maintenance and exacerbation of comorbid symptomatology over time.<b>Discussion:</b> Study findings will provide valuable insight to guide targeted prevention and clinical treatment outcomes.