Circulating PACAP peptide and PAC1R genotype as possible transdiagnostic biomarkers for anxiety disorders in women: a preliminary study.

Pituitary adenylate cyclase activating polypeptide (PACAP, gene Adcyap1) is a neuropeptide and hormone thought to play a critical role in stress response (Stroth et al., Ann NY Acad Sci 1220:49-59, 2011; Hashimoto et al., Curr Pharm Des 17:985-989, 2011). Research in humans implicates PACAP as a useful biomarker for the severity of psychiatric symptoms in response to psychological stressors, and work in rodent models suggests that PACAP manipulation exerts downstream effects on peripheral hormones and behaviors linked to the stress response, providing a potential therapeutic target. Prior work has also suggested a potential sex difference in PACAP effects due to differential estrogen regulation of this pathway. Therefore, we examined serum PACAP and associated PAC1R genotype in a cohort of males and females with a primary diagnosis of generalized anxiety disorder (GAD) and nonpsychiatric controls. We found that, while circulating hormone levels were not associated with a GAD diagnosis overall (p = 0.19, g = 0.25), PACAP may be associated with GAD in females (p = 0.04, g = 0.33). Additionally, among patients with GAD, the risk genotype identified in the PTSD literature (rs2267735, CC genotype) was associated with higher somatic anxiety symptom severity in females but lower somatic anxiety symptom severity in males (-3.27, 95%CI [-5.76, -0.77], adjusted p = 0.03). Taken together, the associations between the risk genotype, circulating PACAP, and somatic anxiety severity were stronger among females than males. These results indicate a potential underlying biological etiology for sex differences in stress-related anxiety disorders that warrants further study.

Understanding the impact of complicated grief on combat related posttraumatic stress disorder, guilt, suicide, and functional impairment in a clinical trial of post-9/11 service members and veterans.

BACKGROUND: Complicated grief (CG) is a bereavement-specific syndrome distinct from but commonly comorbid with posttraumatic stress disorder (PTSD). While bereavement is common among military personnel (Simon et al., 2018), there is little research on the impact of CG comorbidity on PTSD treatment outcomes. METHODS: To evaluate the impact of comorbid CG on PTSD treatment outcomes we analyzed data from a randomized trial comparing prolonged exposure, sertraline, and their combination in veterans with a primary diagnosis of combat-related PTSD (n = 194). Assessment of PTSD, trauma-related guilt, functional impairment, and suicidal ideation and behavior occurred at baseline and weeks 6, 12, and 24 during the 24-week trial. RESULTS: CG was associated with lower PTSD treatment response (odds ratio (OR) = 0.29, 95% confidence interval (CI) [0.12, 0.69], p = 0.005) and remission (OR = 0.28, 95% CI [0.11, 0.71], p = 0.007). Those with CG had greater severity of PTSD (p = 0.005) and trauma-related guilt (<0.001) at baseline and endpoint. In addition, those with CG were more likely to experience suicidal ideation during the study (CG: 35%, 14/40 vs. no CG 15%, 20/130; OR = 3.01, 95% CI [1.29, 7.02], p = 0.011). CONCLUSIONS: Comorbid CG is associated with elevated PTSD severity and independently associated with poorer endpoint treatment outcomes in veterans with combat-related PTSD, suggesting that screening and additional intervention for CG may be needed.