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alcohol consumed when studied in the psychology laboratory. In these studies, dependence was rated by an independent psychiatrist described as an experienced clinician, as being moderate or severe, using the criteria of lifetime history of withdrawal symptoms and of withdrawal relief drinking. Moderate dependence is defined as “subject has at some time experienced withdrawal symptoms of mild or moderate severity a few times a week for some months...on occasion engaged in withdrawal drinking...his drinking pattern is beginning to show some impoverishment of repertoire”. Severe dependence is defined as “subject has at some time experienced withdrawal symptoms of moderate or severe intensity over a period of at least six months, occurring every day or nearly every day. His drinking repertoire is narrowed to a stereo type pattern”. (Hodgson et al. 1979 p. 382). No explanation is offered of the seemingly arbitrary figure of six months nor for the implications of the possibility that “at some time” could have referred to ten years ago; these ratings were validated in a study by Orford et al. (1976) in which they were shown to be predictive of abstinent or controlled drinking outcomes.
Using this method to rate dependence, Hodgson et al. (1979) found that high dependence respondents drank significantly more alcohol during behavioural tests, drank the first drink significantly more quickly and reported greater desire for a drink than respondents rated as moderately dependent. Moreover, the respondents rated with high dependence consumed the first drink significantly more quickly (as measured by number of sips and time taken to consume the drink) after a high priming dose than they did after no priming dose. This was found not to be the case for respondents rated as being of moderate dependence. Hodgson et al. (1979) also demonstrated that degree of dependence determined whether craving for alcohol was primed by a high dose of alcohol. Craving for alcohol, described as a “system of interrelated responses involving subjective, physiological, behavioural and biochemical components” (Hodgson et al. 1979 p. 380) was measured by a subjective rating of desire for a drink, pulse, blood alcohol level as calculated from a fuel cell breathalyser and time taken to consume one drink. In yet another study (Rankin et al. 1980) a behavioural measure of dependence based upon speed of drinking and amount consumed was shown to correlate with craving.
Using a balanced placebo design (Marlatt et al. 1973) to investigate the possible mediating role of cognitive factors, Stockwell et al. (1982) found that the priming effect described above was influenced by both cognitive and physiological factors in high dependence study participants whereas it was influenced only by cognitive factors in the moderately dependent participants. Study participants rated with severe dependence drank more quickly if they were given alcohol, regardless of whether they had been told that they were given alcohol or given a soft drink and they expressed
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