Relationship between craving and plasma leptin concentrations in patients with cocaine addiction.

BACKGROUND: There is robust evidence indicating an overlap between neurobiological circuitry and pathways that regulate addictions and those that regulate appetite and food intake. Rodent work suggests a role of the appetitive peptide leptin in cocaine-seeking behaviours. The goal of this study was to investigate the possible relationship between plasma leptin concentrations and cocaine craving and use in patients seeking treatment for cocaine dependence. METHODS: Patients (N=43) with a DSM-IV diagnosis of cocaine dependence were studied before starting detoxification (baseline; T0) and then again 14days after (T1; only those patients who abstained from cocaine during the study). Blood samples for plasma leptin concentrations were collected and cocaine craving was assessed using the Brief Cocaine Craving Questionnaire (Brief-CCQ). Food craving was also assessed using a food Visual Analogue Scale (f-VAS). Barratt Impulsiveness Scale (BIS) was used to evaluate impulsivity. RESULTS: Plasma leptin concentrations at T0 significantly correlated with baseline Brief-CCQ scores (r=0.34, p<0.05). Furthermore, plasma leptin concentrations at T1 significantly correlated with the baseline amount of cocaine used (r=0.5, p<0.05). There were no significant correlations between plasma leptin concentrations and f-VAS scores either at T0 or T1 (p's>0.05). CONCLUSIONS: The present study suggests a potential relationship between plasma leptin concentrations and cocaine craving and use. Future mechanistic studies are needed to determine whether manipulations of leptin signalling may lead to novel pharmacological approaches to treat cocaine addiction.