Attribution, labeling, and treatment of environmentally-related mood and behavior changes

High rates of untreated affective disorders remain a concern in the United States. The degree to which seasonal depression (depressive episodes occurring predominantly during a specific time of year) contributes to this burden is unclear. Despite widely accepted and available treatments for these disorders, a substantial number of individuals do not obtain appropriate care for reasons that include cultural preferences and situational obstacles. In addition to these barriers to care, individuals' explanatory models influence treatment-seeking decisions. Causal attribution is one facet of this explanatory model. Identifying the characteristics of individuals who attribute mood change to environmental factors contributes to a better understanding of how people develop their causal models and whether causal models that include environmental factors are associated with treatment seeking.;This dissertation addressed three specific research aims, exploring (1) the conditions under which individuals make environmental attributions for recent mood change; (2) the relationship among depressive symptom severity, labeling, and attribution; and (3) the relationship of all of these factors with treatment seeking. A mixed-method study using a purposive national online sample was utilized.;The results of the study indicated that seasonality (highly variable mood and mood-related behavior across seasons) was associated with an increased likelihood of making environmental (i.e., photoperiod) vs. non-environmental (i.e., chemical imbalance) attributions. Further, environmental attributions were associated with clinically labeling symptoms, perceived control over natural light exposure, low perceived illness threat, and a decreased likelihood of seeking clinical treatment. As a whole, these findings indicate a complex relationship among environmental attribution, labeling, and treatment seeking for mood change that is strongly impacted by seasonality and symptom severity. The findings also reveal a need for future investigations of seasonality as a risk factor for depression.;Finding relationships between seasonality, environmental attribution, and illness behaviors in a community sample provides a solid foundation on which to launch future prospective studies regarding the role of environmental factors in causal models and treatment seeking patterns related to affective disorders. If heightened sensitivity to environmental factors places individuals at a greater risk for affective disorders, then understanding the etiology of seasonal mood change could mitigate future episodes.