Using sleep to enhance exposure treatment for anxious children: A pilot study.

Alcohol and cannabis use are highly prevalent among young adults (ages 18-30) with 66.3% reporting past month alcohol use and 22.6% reporting past month cannabis use, according to recent Monitoring the Future data (, ). Research using cross-sectional and ecological momentary assessment (EMA) methods has consistently documented both positive and negative consequences resulting from alcohol (; ; ; ) and cannabis use (; ) within this age group. Notably, the co-use of alcohol and cannabis has been linked to increased overall negative consequences at the daily level (; ; ), as well as positive enhancing effects that may motivate co-use (; ; ) compared to using a single substance (alcohol-only use, cannabis-only use). Therefore, it is vital to examine both positive and negative outcomes associated with both alcohol and cannabis use, along with the factors that contribute to these behaviors. Intentions have been identified as proximal antecedent to alcohol use and related outcomes (; ). Planned use (i.e., reporting intentions and following through on intentions) versus unplanned use (i.e., substance use despite not reporting previous intentions) has been a focus of substance use-related outcomes research in recent years, predominantly with a focus on alcohol outcomes (Howe et al., 2024; . The current study expands on this work by examining planned vs. unplanned alcohol and cannabis use in a co-use sample. Theoretical frameworks, such as the Theory of Planned Behavior (TPB) (, ) and Prototype Willingness Model (PWM) have been instrumental in understanding how intentions influence substance use (). Both the TPB and PWM suggest that intentions, or an individual’s plans to engage in a behavior, are among the most immediate predictors of behavioral outcomes (, ; ; ). A 2016 meta-analysis demonstrated that intentions to consume alcohol are strongly correlated with behaviors such as heavy drinking and the frequency of intoxication (), which are historically robust indicators of likelihood of experiencing consequences (). In the context of the PWM, health behaviors, particularly among youth, can result from two decisional pathways: one in which an individual is willing to engage in a behavior (the social reaction path) and another where behavioral intention is a proximal antecedent to behavior (the reasoned path). Both pathways have been shown to predict substance use outcomes, including number of negative consequences () and greater alcohol use () . These theoretical frameworks provide valuable insights into the role of intentions and planned behavior in substance use. However, research is needed to explore how intentions and plans unfold in real-world settings, using ecologically valid data (i.e., EMA), to better understand their influence on outcomes in everyday contexts. As such, understanding the implications of planned versus unplanned substance use in relation to consequences is both theoretically and clinically important. Furthermore, exceeding one’s planned amount of substance use, is a feature of substance use disorders (SUDs) and a criterion in the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) (). Therefore, examining the relationship between planned and unplanned use and substance use-related outcomes is essential for effectively managing and intervening in harmful substance use.