Venue : Centre Broca Nouvelle-Aquitaine
Thesis defense in French
Emmanuelle Baillet
Sanpsy
Team : Addiction
Thesis directed by Marc Auriacombe
Title
Craving: an early and predictive marker of addiction?
Abstract
Addiction, or substance use disorder (SUD), can be characterized by deregulation of control over the use of reinforcing substances, resulting in persistent use despite negative consequences. Craving, defined as an intense urge to use, is both a diagnostic criterion among the 11 DSM-5 criteria and a fluctuating phenomenon whose daily variations in everyday life explored with the Ecological Momentary Assessment (EMA) method have been prospectively associated with use, giving it a potential prognostic and etiological value. The presence of craving in subjects with mild addiction suggests that it could be an early marker. On the other hand, while craving is a powerful predictor of use and relapse in the short and medium term (1 year), the long-term impact (5 years and more) of its fluctuations is unknown. The cue-reactivity paradigm would lead to both craving and changes in brain and autonomic activity, suggesting that these changes could be the physiological expression of craving. The aim of this PhD project was to investigate the role of craving in the development of addiction, its impact on long-term relapse and its physiological correlates. A total of 1,528 subjects with addiction or use of different substances, in or out of treatment, were included in different protocols. Craving was assessed either as a diagnostic criterion (a trait, presence or absence), or as a fluctuating phenomenon (a state, of variable intensity). DSM-5 diagnostic criteria were used to establish a network of symptoms in patients requesting treatment, and to explore the predictive role of craving on addiction in a longitudinal general population study. The EMA was used to collect craving data, while a wearable sensor was used to collect physiological data over a 14-day period. Multilevel models examined craving fluctuations and their impact on severity and relapse; then machine learning algorithms enabled exploration of its physiological correlates. Our results show that, for different substances, craving was the most central criterion in the network analyses, and that a dose-response relationship for craving and its persistence over 12 months was associated with the number of SUD diagnostic criteria present. Dynamically, variations in craving intensity during the first 14 days of treatment showed a slower decline for people relapsing to addiction after 5 years or more. Finally, we were able to establish a physiological pattern distinguishing craving from no-craving episodes. In this PhD project, we confirm the major role of craving as a central criterion for the expression of addiction, and document that it is an early and predictive criterion in the development and severity of addiction. We show that fluctuations in craving intensity at the start of treatment could be a predictive marker of long-term relapse, i.e., long-term response to treatment, and that a physiological pattern could distinguish craving from no-craving episodes in daily life. These results underline the potential of craving as a marker of addiction and pave the way for biomarkers of craving, offering new insights into its underlying mechanisms and new methods of identification and treatment.
Key words
Craving; Addiction; Ecological Momentary Assessment (EMA); Biomarkers; Autonomous reactivity
Jury
Pr Anna-Rose Childress (rapportrice)
Pr George Brousse (rapporteur)
Dr Sandra Chanraud (Examinatrice)
Dr Leonie Koban (Examinatrice)
Dr Serge Ahmed (Examinateur)
Dr Charlotte Kervran (Invitée)
Dr Hakim Si-Mohammed (Invité)