Examining The Mental Health And Temperature Relationship In North Carolina

Adverse mental health outcomes have been associated with high temperatures in studies around the world. Despite the breadth of research there are few studies that explore a broad range of mental health outcomes and, to our knowledge, none specific to North Carolina, USA. This study uses a distributed lag non-linear model (DLNM) to explore the relationship between ambient temperature and mental health outcomes (suicide, self-harm and suicide ideation, anxiety and stress, mood disorders and depression) in North Carolina. The results were predominately insignificant with some key exceptions. The county with the highest climate variability (Wake) displays high levels of significance while counties with the lowest climate variability (New Hanover and Pitt) are almost entirely insignificant. This finding coincides with other studies that observe a weaker temperature-mental health relationship in geographies with low seasonal variability and for populations more adapted to the heat. Additionally, the temperature-mental health relationship changes with respect to various outcomes and lag periods. Self-harm and suicidal ideation peaks in the warm period (June - August) and displays an increase in risk at shorter lag periods (0-5 days). Anxiety, depression, and major depressive disorders peak in the cooler months (May and September) while the highest risk is observed at longer lag periods (15-20 days). Suicide is the only outcome that favored a 20-day lag period in the sensitivity analysis. These observations suggest that there are a number of unexplored pathological and environmental variables affecting the temperature-mental health relationship.