Comparing Startle Reactivity in Cannabis Dependent Females with Cannabis Withdrawal Syndrome vs. Non-User Controls Matched on Psychopathology: A Test of the Allostatic Model of Addiction

Abstract

Cannabis Use Disorder (CUD) is expected to increase in the United States, necessitating research examining markers that may predict CUD trajectory. As chronic and harmful cannabis use develops, homeostatic thresholds to stress are altered, resulting in an allostatic load indicative sensitization to acute stress. One physiological marker that may be affected by a greater allostatic load from disordered cannabis use is the startle reflex. Previous studies examining startle reactivity in cannabis users compared to non-users is mixed, possibly due to methodological limitations, such as greater between-subject variability due to a) cannabis use severity, b) differences in internalizing psychopathology, and c) participant sex. The current study aimed to minimize variability between cannabis users and non-users and compare startle reactivity in different threatening contexts. Cannabis users who met for severe CUD with a history of withdrawal were compared to non-using participants matched on psychopathology on startle blink magnitude to no-threat, predictable threat, and unpredictable threat. Results revealed that, compared to non-users, the CUD group demonstrated greater startle blink magnitude to unpredictable and predictable threat during one portion of the startle reactivity task. Current results are consistent with previous alcohol- and nicotine-related studies examining startle reactivity and suggest that greater allostatic load in the CUD group may contribute to sensitization to stressful events. Startle reactivity may be beneficial as a marker to predict CUD trajectory, in addition to being the target for interventions designed to minimize CUD relapse in those seeking abstinence.