Between-subjects literature has established that trait-like negative mood predicts coping motives, which predict alcohol-related problems and that trait-like positive mood predicts mood enhancement motives, which then predict alcohol consumption. However, there is considerable within-person variation in drinking motives, and the relationship between mood, motives, and alcohol outcomes must be more closely examined at a daily level. The current study used ecological momentary assessment (EMA) to measure mood, motives, alcohol use, and alcohol consequences in 101 college drinkers over a 15-day period. At the between-subjects level, positive mood predicted enhancement motives, which in turn predicted alcohol consumption and consequences. Negative mood predicted coping motives, which were associated with only alcohol-related consequences. At the withinsubjects level, daily anxious and depressed mood were associated with endorsing coping motives, but coping motives were not associated with alcohol consumption or problems. Positive mood was associated with enhancement motives, which was associated with both daily alcohol consumption and problems. These results corroborate previous findings that enhancement motives are most predictive of outcomes in the college population and highlight the importance of considering within-subject variance in drinking motives. The relationships between mood, motives, and alcohol outcomes differ when examined as between-subjects versus within-subject constructs.

Several theories posit problematic alcohol use develops through mechanisms of positive and negative reinforcement. However, the literature on these mechanisms remains inconsistent. This may be due to a number of issues including a failure to disaggregate negative mood or a failure to account for mood functioning (i.e., stability in mood). Alternatively, there may be differences in typical postdrinking/evening mood on drinking and nondrinking days, however, this has yet to be fully explored. We examined multiple indices of distinct mood states prior to and after typical drinking onset times on drinking and nondrinking days using ecological momentary assessment. College student drinkers ( = 102) carried personal data devices for 15 days. They reported on mood and alcohol use several times per day. Tonic positive mood was higher on drinking days than nondrinking days prior to typical drinking initiation. After typical drinking times, positive mood was higher on drinking days than nondrinking days. Similarly, negative moods (anxiety, stress, anger, and stress instability) indicated a pattern of lower levels relative to both predrinking mood on drinking days, and matched mood time-points on nondrinking days; though, not all of these differences were statistically different. Results suggest positive and negative reinforcing mechanisms may be at play-though the negative reinforcement effects may manifest through subjectively "better" mood on drinking versus nondrinking days. (PsycINFO Database Record

Abstract-Blood pressure (BP) fluctuates over a 24-hour period, but it is unclear to what extent this variation is governed completely by changes in physical activity. Our aim was to use a BP "reactivity index" to investigate whether the BP response to a given level of physical activity changes during a normal sleep-wake cycle. Hypertensive patients (nϭ440) underwent simultaneous 24-hour ambulatory BP, heart rate (HR), and activity monitoring. BP and HR were measured every 20 minutes. Actigraphy data were averaged over the 15 minutes that preceded a BP measurement. Individual BP and HR reactivity indices were calculated using least-squares regression for twelve 2-hour periods. These indices were then analyzed for time-of-day differences using a general linear model. Systolic BP and HR were generally more reactive to physical activity than diastolic BP. The highest reactivity of systolic BP (meanϮSEϭ4Ϯ1 mm Hg per logged unit change in activity) was observed between 8:00 AM and 10:00 AM (Pϭ0.014). Between 10:00 AM and 12:00 PM, BP reactivity then decreased (Pϭ0.048) and showed a secondary rise in the early afternoon. These 24-hour changes in BP reactivity did not differ significantly between groups formed on the basis of early and late wake times (Pϭ0.485), medication use, age, and sex (PϾ0.350). In conclusion, under conditions of normal living, the reactivity of BP and HR to a given unit change in activity is highest in the morning and shows a secondary rise in the afternoon.

Daytime and night-time physical activity levels are independently and significantly predictive of the magnitude of the nocturnal dip in blood pressure. Variation in activity may confound interpretation of 24-h ambulatory blood pressure monitoring, and contribute to the poor reproducibility of dipper status.