While caffeine withdrawal has been well-characterized, research on caffeine intake and factors associated with withdrawal has been limited. The present study examined prevalence rates of caffeine use and identified psychosocial factors associated with having caffeine withdrawal headaches (CWH). Participants were N = 1,989 college freshmen who participated in the 2011 Spit for Science project. Caffeine use was reported by 80% of the sample. Females were more likely than males to consume caffeine, and soda was the primary source of caffeine for both genders. As hypothesized, daily caffeine users were more likely to report CWH than non-daily users. When multivariable analyses examined other variables identified through univariable analyses, the most parsimonious model for distinguishing between those with and without CWH included the following set of predictor variables: daily caffeine use; female; non-white minority; peers with alcohol problems; greater neuroticism, and those reporting maternal depression or anxiety.

The mechanisms underlying caffeine’s acute effects and withdrawal symptoms are not entirely understood. The purpose was to determine whether these effects or symptoms co-exist in clusters, and whether they are associated with polymorphisms in β1- and β2-adrenoceptors. Subjects (n=1271) were from the Toronto Nutrigenomics and Health Study. The acute effects and withdrawal symptoms clustered into 4 and 6 factors, respectively. Subjects with the ADRβ2 Gly16Arg Gly/Arg genotype were more likely than Gly allele homozygotes to report “fatigue” withdrawal symptoms. Among >200 mg/d caffeine consumers, ADRβ2 Gly allele carriers had a greater risk, compared to Arg allele homozygotes, of reporting ‘flu-like somatic’ withdrawal symptoms. Among subjects with the CYP1A2 -163 A>C A/A genotype and 100-200 mg/d caffeine consumers, ADRβ1 Arg389Gly Gly allele carriers had a greater risk, compared to Arg allele homozygotes, of reporting “dysphoric mood” withdrawal symptoms. The findings suggest that β1- and β2- adrenoceptors play a role in caffeine withdrawal.

The mechanisms underlying caffeine’s acute effects and withdrawal symptoms are not entirely understood. The purpose was to determine whether these effects or symptoms co-exist in clusters, and whether they are associated with polymorphisms in β1- and β2-adrenoceptors. Subjects (n=1271) were from the Toronto Nutrigenomics and Health Study. The acute effects and withdrawal symptoms clustered into 4 and 6 factors, respectively. Subjects with the ADRβ2 Gly16Arg Gly/Arg genotype were more likely than Gly allele homozygotes to report “fatigue” withdrawal symptoms. Among >200 mg/d caffeine consumers, ADRβ2 Gly allele carriers had a greater risk, compared to Arg allele homozygotes, of reporting ‘flu-like somatic’ withdrawal symptoms. Among subjects with the CYP1A2 -163 A>C A/A genotype and 100-200 mg/d caffeine consumers, ADRβ1 Arg389Gly Gly allele carriers had a greater risk, compared to Arg allele homozygotes, of reporting “dysphoric mood” withdrawal symptoms. The findings suggest that β1- and β2- adrenoceptors play a role in caffeine withdrawal.