Implication du craving dans la consommation de substances chez les sujets dépendants. Une étude d’évaluation écologique momentanée (CUSEMA)

Context

Addiction is characterized by the loss of control of use of reinforcing substances, and persistent use despite its negative consequences. The current definition of addiction emphasizes the inability to control use that is expressed though relapse and craving. Craving, defined as a strong unwanted desire to use the substance, is currently considered a central component of addiction and possible proximal marker. Craving is a complex subjective phenomenon strongly influenced by the environmental context and likely to show rapid fluctuations over periods of hours. The study of craving has benefited from the contributions of mobile technologies that allow the collection of data in daily life (Ecological Momentary Assessment or EMA). Results of EMA studies in daily life has shown a prospective link between craving episodes and substance use, underlining the major role of craving in the relapse process, and the probable involvement of this phenomenon in the chronicity of the disorder. However, craving has been mainly studied among patients in treatment. As a result, the link between craving and use could be an artifact of attempting to stop use due to the context of care and not an independent expression of addiction. A majority of patients with addiction are not currently in treatment. Preliminary data suggest that craving could also be a major contributor to substance use and risk practices among subjects with addiction who are not in a process of stopping substance use. It is important to understand the motivations for use among such individuals, to better understand what differentiates problem users not in treatment from those in treatment, in order to better help them to access treatment.

Objectives

The main objective is to examine if the relationship between craving and substance use is modified by the context of care (active users vs. patients attempting to reduce use or abstain in addiction treatment), in subjects with a substance use disorder, in the context of daily life. The secondary objectives will be (i) to examine the influence of various factors or mediators on craving, substance use, and on the link between cues and craving, and between craving and substance use in daily life, according to the context of care (e.i. insight level, addiction severity, cues, socio-demographics characteristics); and (ii) to examine the influence of craving on substance use related risk practices.

Research hypothesis

Based on a pilot study, we hypothesize that the prospective link between craving and substance use in daily life will be found regardless of the context of care.

Methods

This study is a 14-days prospective multi-daily observational multicentric study, recruiting 2 groups of participants: a group of substance users recruited in Harm Reduction programs: “active users”; and a group of patients initiating addiction treatment focused on abstinence/reduction of substance use: “patients in treatment”. The inclusion criteria common to both populations will be to identify at least one main problematic substance (opiates, cocaine, cannabis, tobacco, alcohol) and qualify for a DSM-5 substance use disorder diagnosis. Baseline interview will include assessment of substance use and addiction severity (ASI), psychiatric comorbidities (MINI), insight (HAIS-m). All participants will receive a 2-week period of EMA assessments monitoring craving, substance use, environmental context, moods, risk practices, location, cues, other substances use, with a maximum of 4 questionnaires per day. HLM models will examine the prospective link between craving levels at any given assessment (T0) and substance use at the next assessment (T1, approximately 4 hours later). The main evaluation criterion will be the influence of context of care (“active users” vs. “patients in treatment) in this relationship. A total of 196 participants will be necessary.

Perspectives

If the role of craving in substance use is confirmed for “patients in treatment”, the results could provide clarification on new therapeutic approaches focused on craving anticipation and management. If the role of craving in substance use is confirmed in “active users”, this could allow to design innovative tools to help them to better identify craving and possibly prevent some of its harmful consequences.

Public health impact

This project will provide a better understanding of the mechanisms of addiction, including the role of craving in motivation to use in different care settings, but also a better understanding of trajectories of subjects with addictive disorders relative to their treatment approach. The proportion of individuals with addiction accessing treatment is estimated to be less than 25%. A better understanding of what differentiates patients in treatment from subjects who are not yet in treatment or who are not requesting treatment could be helpful to improve access to treatment.