Mental Health Impact of Post-Herpetic Neuralgia: A Retrospective Cohort Study from 33,201 Patients Using TriNetX Network Database

Background Postherpetic neuralgia (PHN) is known to cause pain and affect quality of life. Nonetheless, its association with subsequent mental disorders or severe psychiatric conditions remain underexplored, especially in large and diverse populations. The aim of this study is to identify the risks mental disorders in patients with PHN, with a large-scale, real-world dataset in TriNetX. Methods This retrospective cohort study utilized the TriNetX U.S. Collaborative Network and included patients aged ≥ 18 years with new diagnosis of herpes zoster from 2016 to 2023. Patients were divided into PHN and non-PHN groups. The PHN group comprised patients diagnosed with PHN within one month after the diagnosis of herpes zoster, while the non-PHN group comprised those without PHN. Participants diagnosed with any mental disorders before the diagnosis of herpes zoster or up to one month after it were excluded. Each group included 33201 patients after propensity score matching. Risks of mental disorders were compared between the two groups over a 6-month follow-up. Subgroup analyses were conducted across age, sex, race, herpes zoster vaccination, and disease site. Results Our results suggested that patients with PHN had a significantly higher risk of developing mental disorders (hazard ratio [HR]: 1.23, 95% confidence interval [CI]: 1.13–1.34), especially in younger patients aged 18–64 (HR: 1.30, 95% CI: 1.15–1.47). Among categories of mental disorders, significant elevated risks for PHN patients were observed in mood disorders (HR: 1.25, 95% CI: 1.10–1.42), anxiety-related conditions (HR: 1.17, 95% CI: 1.06–1.30), and behavioral syndromes (HR: 1.35, 95% CI: 1.03–1.75). Subgroup analysis showed increased risks of mental disorders for females (HR: 1.17, 95% CI: 1.05–1.30), White patients (HR: 1.17, 95% CI: 1.06–1.30), and Black patients (HR: 1.34, 95% CI: 1.01–1.77), and patients with ocular herpes zoster (HR: 1.63, 95% CI: 1.20–2.21). Conclusions This retrospective cohort study showed a significantly elevated risk for PHN participants to develop mental disorders, particularly in younger adults, females, and White and Black racial groups. Our results also underlined the severe psychological effect of mental disorders associated with PHN. Clinicians should consider early psychological evaluation and intervention for PHN patients.