The paper written by Littlefield and colleagues  examines the scientifically and clinically important area of identifying and classifying individuals based on their drinking motivation. In recent decades, researchers have provided ample empirical evidence pointing to the existence of two general motives [2-5]: drinking to enhance positive mood (often including social aspects such as drinking to have fun with others) and drinking to cope with negative emotions. This would suggest distinct groups of enhancement and coping drinkers. More recently, however, researchers have gone beyond merely associating variables in a bid to identify individuals who sit firmly in one camp or the other, i.e. those who drink for enhancement and those who drink to cope.
Finding no evidence to suggest distinct groups of enhancement and coping drinkers (only a one-cluster solution), Littlefield and colleagues conclude that drinking motives are continuous multi-dimensional constructs that tend to coexist within individuals. I tend to agree with this conclusion, as it is rare to find homogeneous groups of individuals who have only one drinking motive. Furthermore, the authors conclude that, given the lack of evidence to suggest that coping and enhancement motivated drinkers form two distinct groups, effective intervention should address various drinking motivations rather than either coping or enhancement motives. I am more sceptical on this point.
First, it is not surprising that a cluster analysis based on raw drinking motive scores failed to distinguish enhancement and coping drinkers. In all previous studies of which I am aware, strong correlations have been found between drinking motive dimensions [5, 6]. Therefore, even if two clusters are fixed, individuals differ mainly in their overall drinking motivation rather than in terms of enhancement or coping [7, 8]. Gmel and colleagues  argued recently that inter-motive correlations can be attributed largely to response bias. If so, raw motive scores (as used by Littlefield and colleagues) that do not account for response bias are ill-suited to detecting differences in individual drinking motivations . For example, two individuals may have identical raw scores for a given motive (e.g. coping), but one may endorse that motive the least, whereas the other endorses it the most.
Rank scores or any other motive transformations are therefore better suited to identifying enhancement and coping drinkers based on their general (and highly intercorrelated) drinking motive patterns [8, 9].
Secondly, in conceptual terms, enhancement as approach motivation and coping as avoidance motivation are regulated by two neurologically distinct motivational systems . Individuals are thought to differ in a stable, trait-like manner in their relative sensitivity to the behaviour inhibition system that causes avoidance of undesired outcomes, and controls the experience of negative emotions and the behaviour activation system that causes approach towards goals and controls the experience of positive emotions. As such, enhancement and coping motives have distinctive and often contrasting correlates (summarized in Table 1).
|Domain||Enhancement motives||Coping motives|
|Proportion of females||Low||High|
|Drinking at home||Low||High|
|Drinking at a friend's home||High||Low|
|Drinking with same sex friends||High||Low|
|Drinking at bars||High||Low|
|Suppression of aggression||Low||High|
Moreover, several studies have demonstrated that enhancement motives lead to adverse consequences due to the large amounts of alcohol consumed, while coping motives are associated with consequences which go beyond simply the quantity of alcohol drunk [5, 6]. Even the few direct consequences of enhancement motives (e.g. blackouts) differ from those of coping motives (e.g. academic/occupational problems and poor self-care) .
Thus, although it is unlikely that an individual is motivated to drink by either enhancement or coping exclusively, it appears equally unlikely that both motivations are pronounced within an individual to a similar degree because the desired goals (approach versus avoidance) are too contradictory, as are the correlates and consequences. For me, the question remains: how can we best distinguish them in a given population?
Thirdly, in their intervention study, Conrod and colleagues assigned adolescents to distinct groups based on personality traits linked closely with drinking motives (impulsivity, sensation-seeking: enhancement; anxiety–sensitivity, hopelessness: coping) . In each group, one of the intervention tools discussed substance use ‘as having a particular motivational (functional) association with the target personality trait (e.g. alcohol having anxiolytic properties for anxiety–sensitive individuals or stimulant properties for sensation seekers)’ (, p. 300). The results demonstrated the effectiveness of this group-specific intervention in reducing adolescent drinking over a period of 24 months .
In terms of prevention, it therefore appears sensible to target groups that differ in enhancement and coping motives and the associated personality traits.
That said, I believe Littlefield et al.'s work makes a valid contribution to the field. Having demonstrated that using raw drinking motive scores results in a one-cluster solution from which it is impossible to distinguish motive subgroups, the paper raises awareness and fuels the discussion as to whether theoretical types of drinkers actually exist. I look forward to seeing whether future research will succeed in proposing better solutions on how to identify enhancement and coping drinkers.
Declaration of interests