Air mass advection and immune dysregulation in schizophrenia: an exploratory pilot study

Schizophrenia is a severe and clinically heterogeneous mental disorder with an unpredictable course. Growing evidence indicates that immune dysregulation and environmental factors, including weather conditions, may influence symptom exacerbations. Although seasonality has been repeatedly described, the impact of specific meteorological variables - particularly wind and air masses - remains insufficiently explored, and biochemical correlates of weather exposure are rarely examined, despite the fact that wind could inherently convey a complex suite of region-specific meteorological data, thereby offering a more holistic and integrated index of environmental exposure. This exploratory pilot study evaluated two distinct biometeorological approaches - local wind vector decomposition versus macro-scale air mass advection - to examine their associations with psychopathology and cytokine profiles in patients with schizophrenia.

This cross-sectional observational study included a total cohort of 104 participants, consisting of 19 healthy controls and 85 patients with schizophrenia. Psychopathology was evaluated using the Positive and Negative Syndrome Scale (PANSS). Serum levels of TNF-α, IFN-γ, IL-6, and IL-4 were measured and analyzed for 84 subjects, comprising 19 controls and 65 patients with schizophrenia. Weather exposure was analyzed using two models: (1) a local approach, decomposing wind direction into meridional and zonal vector components using trigonometric transformation (3-day average) and (2) a synoptic approach, calculating 7-day backward air mass trajectories, categorized into Arctic, Polar Continental, Polar Maritime, and Tropical types.

Among patients with schizophrenia, Tropical air masses were associated with lower IFN-γ and TNF-α concentrations than all other air mass types (Kruskal-Wallis p = 0.016 and p = 0.001, respectively; all adjusted post-hoc p < 0.05). The association between air mass type and ln(IFN-γ) differed by health status: Tropical air masses were associated with lower ln(IFN-γ) in patients but higher ln(IFN-γ) in healthy controls compared with Polar Maritime and Arctic air masses (both interaction contrasts p < 0.001). Patients had higher IFN-γ than controls under polar maritime and Arctic air masses, whereas no between-group difference was observed under Tropical air masses. Neither air mass type nor continuous wind-vector components were associated with PANSS scores.

Patients with schizophrenia and healthy controls exhibited directionally opposite IFN-γ patterns across air mass types, suggesting health-status-dependent immune responsiveness to synoptic environmental conditions. This pilot study highlights that macro-scale air mass advection, rather than local wind direction components, may represent a more informative environmental proxy for detecting weather-induced immune modulation. Although this study is constrained by a major limitation regarding sample size, these preliminary findings warrant further investigation.