By Emily Pond

June 22, 2021 - Study data published in JAMA Network Open underline the substantial burden of mental illness among former and active coal miners in the US. In a cohort study of coal miners in Virginia, anxiety, depression, and suicidal ideation were present in exceptionally high rates compared with the general population from the same region.

Investigators extracted data from Stone Mountain Health Services (SMHS), a network of clinics providing medical, behavioral, and legal services to active and former coal miners in Virginia. In 2018, SMHS implemented routine mental health screening for patients who received care for occupational exposure to respiratory hazards. The screening procedure captured symptoms of anxiety, depression, and post-traumatic stress disorder (PTSD) using the 2-item Generalized Anxiety Disorder scale (GAD-2), the 9-item Patient Health Questionnaire (PHQ-9), and the 4-item Primary Care-PTSD scale (PC-PTSD-4).

Mental health data obtained between 2018 and 2020 were included in analyses. Demographic and clinical features were extracted from medical records. Descriptive statistics were used to summarize characteristics of the study population; chi-squared tests were used to detect associations between occupational exposures and risk for mental illness.

Between 2018 and 2020, a total of 2826 coal miners received care at an SMHS clinic, among whom 2808 (99.4%) completed a mental health screening evaluation. Median (interquartile range [IQR]) age was 66 (60-71) years; 2808 (99.5%) were White and 2817 (99.7%) identified as male.

A total of 883 patients (37.4%) had symptoms consistent with major depressive disorder (PHQ-9 score ≥10); 1005 (38.9%) had clinically significant anxiety (GAD-2 score ≥3); and 639 (26.2%) had substantial symptoms of PTSD (PC-PTSD-4 score ≥2)., Of those with major depressive disorder, 295 patients (11.4%) also reported active suicidal ideation.

Of 1294 participants who underwent a chest radiograph during the study period, 79.1% and 16.2% had evidence of coal workers’ pneumoconiosis and progressive massive fibrosis, respectively. Airflow obstruction was identified in 906 patients (36.5%).

Chronic hypoxemia, defined by current use of supplemental oxygen, was reported by 508 patients (18.6%). Compared with patients without hypoxemia, patients with hypoxemia were significantly more likely to report symptoms consistent with anxiety (37.6% vs 47.7%), depression (35.5% vs 48.5%), and suicidal ideation (10.5% vs 15.9%; all P <.001). However, radiographic lung abnormalities were not significantly associated with mental health symptoms.

Per these data, the prevalence rates of depression, anxiety, and PTSD in current and former coal miners far exceed those from the general population. Chronic hypoxemia was associated with mental health symptoms, though the small study cohort prevents the assertion of causality.

“Increased assessment of and treatment for unmet mental health needs should be considered for all active and former coal miners,” the study investigators wrote. “Further study is needed to investigate other risk factors for mental illness in this population, including economic security, substance use disorders, and workplace safety.”

Disclosure: One of the study authors served as a statistical consultant for the National Institute of Occupational Health and Safety.