The nature of acute and chronic stress is explored, including analysis of three different ways of categorizing the duration of a stressful episode: the duration of the physical stressor, the duration of threat perception or demand, and the persistence of response. Of particular interest here are situations characterized by brief stressor exposure but long‐term threat perception and/ or stress response. Traumatic events are ordinarily very brief but frequently give rise to chronic threat and stubborn response patterns. In many of these cases, distress clearly outlives the event and the “normal” postevent recovery period. Possible mechanisms for such situations are discussed, as are implications for the study of traumatic stress.

In a residential research ward coffee drinking was studied in 9 volunteer human subjects with histories of heavy coffee drinking. A series of five experiments was undertaken to characterize adlibitum coffee consumption and to investigate the effects of manipulating coffee concentration, caffeine dose per cup, and caffeine preloads prior to coffee drinking. Manipulations were double-blind and scheduled in randomized sequences across days. When cups of coffee were freely available, coffee drinking tended to be rather regularly spaced during the day with intercup intervals becoming progressively longer throughout the day; experimental manipulations showed that this lengthening of intercup intervals was not due to accumulating caffeine levels. Number of cups of coffee consumed was an inverted U-shaped function of both coffee concentration and caffeine dose per cup; however, coffee-concentration and dose-per-cup manipulations did not produce similar effects on other measures of coffee drinking (intercup interval, time to drink a cup, within-day distribution of cups). Caffeine preload produced dose-related decreases in number of cups consumed. As a whole, these experiments provide some limited evidence for both the suppressive and the reinforcing effects of caffeine on coffee consumption. Examination of total daily coffee and caffeine intake across experiments, however, provides no evidence for precise regulation (i.e., titration) of coffee or caffeine intake.

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Research on the acute and chronic effects of victimization by disaster has found that some patterns of response generalize across disasters of different origin and type. However, it is likely that variation in the nature of the victimizing event can affect long-term psychophysiological reactions. This study compared 23 flood victims with 27 people living near a leaking hazardous toxic waste dump and 27 control subjects. Self-report, behavioral, and physiological measures of stress were collected, all of which showed that 9 months after the announcement of the toxic hazard and the destructive flood, subjects living near the waste dump were more anxious, depressed, and alienated, less able to perform challenging tasks, and more aroused than were flood victims or control subjects. Residents of the landfill neighborhood also reported more feelings of helplessness than did any other subjects, and these feelings were significantly correlated with stress. Victimization associated with the toxic landfill appeared more likely to pose threats to victims' sense of control and to cause chronic emotional and psychophysiological problems than did the natural disaster.