Influence of circadian typology on drug consumption, hazardous alcohol use, and hangover symptoms.

Few studies have focused on the influence of circadian typology on drug use, and none has considered the use of illegal drugs and hazardous alcohol consumption. This study analyzes the influence of circadian typology on several types of drug consumption (habitual or sporadic), hangover symptoms (past 12 mos), and, more specifically, hazardous alcohol consumption of young adults. Five hundred seventeen university students (173 males), between 17 and 30 yrs of age, answered the Composite Scale of Morningness (CSM), the Alcohol Use Disorders Identification Test (AUDIT), and a self-referred questionnaire on drug consumption during the previous month and on the prevalence of different hangover symptoms during the previous year. Our results confirm a higher prevalence of consumption of addictive substances, both legal (nicotine and cola drinks) and illegal (cannabis and ecstasy), in evening- compared to morning- and neither-type subjects (p < .001 in all cases). Evening-type subjects also obtained a higher total score on the AUDIT (p < .001) and showed a greater prevalence in the subscales of potential alcohol problems (p < .02), as well as more frequent different hangover symptoms (learning difficulties, thirst, tiredness, headaches, sensorial hypersensitivity, anxiety, and irritability; p < .04 in all cases) compared with morning- and neither-type subjects, except for sensorial hypersensitivity and anxiety, for which the evening-type did not differ from the neither-type. Our results provide substantial evidence that the evening circadian typology is a risk factor for the development of drug consumption and that it should be taken into account both in preventive and treatment approaches. Moreover, the data regarding hazardous alcohol use and hangover symptoms emphasize the need to include circadian typology in future studies on the pattern of heavy episodic drinking.