In this study coffee consumption is correlated with difficulty regulating emotions:
“Alexithymia refers to difficulties with identifying, describing, and regulating one’s own emotions. This trait dimension has been linked to risky or harmful use of alcohol and illicit drugs; however, the most widely used psychoactive drug in the world, caffeine, has not been examined previously in relation to alexithymia. The present study assessed 106 male and female university students aged 18-30 years on their caffeine use in relation to several traits, including alexithymia. The 18 participants defined as alexithymic based on their Toronto Alexithymia Scale (TAS-20) scores reported consuming nearly twice as much caffeine per day as did non-alexithymic or borderline alexithymic participants. They also scored significantly higher than controls on indices of frontal lobe dysfunction as well as anxiety symptoms and sensitivity to punishment. In a hierarchical linear regression model, sensitivity to punishment negatively predicted daily caffeine intake, suggesting caffeine avoidance by trait-anxious individuals. Surprisingly, however, TAS-20 alexithymia scores positively predicted caffeine consumption. Possible reasons for the positive relationship between caffeine use and alexithymia are discussed, concluding that this outcome is tentatively consistent with the hypo-arousal model of alexithymia.”
Note that correlation does not prove causation.