Emotion differentiation among individuals in a randomized clinical trial for alcohol use disorder: Within- and between-person associations with affect, craving, and alcohol use in daily life*,**

Emotion differentiation refers to cognitively distinguishing among discrete, same-valenced emotions. Negative emotion differentiation (NED) is a transdiagnostic indicator of emotional functioning. The role of positive emotion differentiation (PED) in clinical disorders, including alcohol use disorder (AUD), is less understood. Further, despite consensus that emotions are highly variable, little is known about within-person fluctuations in NED/PED. The current study leveraged 84 consecutive daily smartphone surveys from participants (N = 181) in a clinical trial of cognitive behavioral therapy for AUD to investigate whether between-person differences in overall NED/PED, or within-person variability in daily NED/PED, were associated with affect intensity, craving, drinking, and heavy drinking in daily life. Subsequent analyses explored whether associations were moderated by baseline alexithymia. At the between-persons level, greater average PED, but not NED, was associated with lower heavy drinking odds. At the within-persons level, higher-than-usual PED was associated with lower negative affect and odds of any drinking. Individuals with baseline alexithymia had stronger negative withinperson associations between daily NED and both any and heavy drinking. PED is a skill linked to less alcohol use between- and within-persons irrespective of baseline alexithymia, whereas greater daily NED appears especially important for reduced alcohol use among individuals with co-morbid AUD and alexithymia.