Date of Award


Document Type


Degree Name

Doctor of Philosophy (PhD)



First Advisor

Kelly J. Rohan


Winter seasonal affective disorder (SAD) is a depression subtype in which episodes recur in the fall/winter months and remit in the spring/summer months. In laboratory studies, SAD patients show distinct emotional and psychophysiological responses to videos or photographs of light and seasonal stimuli. (e.g., winter scenes, overcast skies). Affective shifts upon exposure to such stimuli is consistent with learning theory, positing that greater attention is allocated to cues with predictable outcomes, i.e., in the case of SAD, winter/low light cues signaling an impending depressive episode. This project tested a model positing that increased attention to seasonal and light cues leads to anticipatory anxiety about the upcoming winter, which is followed by depressive symptoms, particularly among those with a longer history of SAD. Attention to seasonal and light cues and depressed and anxious mood were prospectively tracked over 21-days using ecological momentary assessment in 41 adults with SAD. Participants were recruited in the fall/winter prior to development of a depressive episode to track a time of expected depression symptom growth. A multilevel confirmatory factor analysis operationalized the attention variable with two factors, Attention to Positive Cues (PA; indicators = sunshine, clear skies) and Attention to Negative Cues (NA; indicators = gray skies, cloud cover, rain). In multilevel structural equation models, the direct effect of NA was not significant at either the within- or between-person levels on either daily depression or daily anxiety. Anticipatory anxiety did not mediate the relationship between NA and depressed mood, and number of prior SAD episodes did not moderate the relationship between NA and anticipatory anxiety. When breaking up the sample by prior treatment status, there was a trend suggesting lower NA among participants with prior exposure to SAD treatment with cognitive-behavioral therapy or light therapy relative to treatment naïve participants. Results suggest greater attention to light than seasonal cues in this sample; however, attention towards light cues was not related to daily depression or anxiety. This study is limited by insufficient power. Future studies should examine attention to light cues in relation to SAD symptoms beyond mood (e.g., fatigue) and the interaction of attention with cognitive appraisals of these cues.



Number of Pages

54 p.

Available for download on Monday, May 12, 2025