Impact of sleep disorders and disease duration on neurotrophins levels in cocaine use disorder.

INTRODUCTION:Brain-derived neurotrophic factor (BDNF) and its precursor proBDNF contribute to brain plasticity and neuronal remodeling. Recently, the ratio between proBDNF and BDNF (RpB) has been proposed as a possible marker in major psychiatric disorders. Convergent lines of evidence suggest neurotrophins alterations could be involved into the pathophysiology of Cocaine Use Disorder (CUD) and insomnia. The aims of the present study are to evaluate the correlations between neurotrophins levels, insomnia and clinical features among CUD patients. MATERIALS AND METHODS:Subjects with a moderate to severe CUD were recruited. ProBDNF, BDNF and consequently RpB values were analyzed using ELISA technique. Insomnia severity index (ISI) scale was used to assess the severity of insomnia. Sociodemographic characteristics and CUD habits (e.g., years of cocaine use) were also collected. RESULTS:Twenty-four subjects (mean age 39.3 ± 6.7 years) were recruited. Correlation analysis showed that lower values of RpB were associated with higher ISI score (r = -0.469; p = 0.021), longer history of cocaine use (r = -0.584, p = 0.022) and higher amount of cocaine used (r = -0.655, p = 0.004). DISCUSSION:These preliminary findings may offer a novel insight on neurobiological alterations sustaining cocaine use. Lower RpB, as observed both in high insomnia levels and in chronic cocaine use, could induce a neuroprotective state as a synaptic homeostatic response to chronic damage. These findings also highlight the important role of neurotrophins balance on neurobiological alterations induced by cocaine misuse and insomnia, suggesting that RpB could be considered as a marker of neurotrophic and metabolic state of neural tissue.