Modulation of neuropeptide Y levels is impaired in crack withdrawal patients

Abstract Introduction The dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis has a key role in drug addiction susceptibility. In addition to the well-known relationship between cortisol and the HPA axis, other molecules are involved with stress response and could modify the HPA activation, such as the neuropeptide Y (NPY), which has anxiolytic proprieties. There are few studies evaluating the effect of NPY levels on addiction, especially in crack cocaine dependence. Objective To evaluate NPY in crack users during early withdrawal to determine its relationship with drug use and cortisol levels. Methods We analyzed 25 male inpatient crack users. Serum NPY levels were measured at admission and discharge (mean of 24 days). Morning salivary cortisol was measured at admission. Results Serum NPY levels at admission and discharge were very similar. Lower NPY levels at discharge were associated with higher lifetime crack use. Also, a negative correlation was found between morning cortisol and delta NPY (NPY discharge - NPY admission). Conclusion These preliminary findings indicate that crack use influences the modulation of NPY levels and modifies stress response. The NPY pathway may play an important role in the pathophysiology of crack addiction, and the anxiolytic effect of NPY may be impaired in crack users. Future studies should consider NPY as a measurable indicator of the biological state in addiction.

Effects of childhood trauma on BDNF and TBARS during crack-cocaine withdrawal

Objective: To evaluate the association between childhood trauma (CT) and serum levels of brain-derived neurotrophic factor (BDNF) and thiobarbituric acid-reactive substances (TBARS) during crack-cocaine withdrawal. Method: Thirty-three male crack-cocaine users were recruited at admission to a public addiction treatment unit. Serum BDNF and TBARS levels were evaluated at intake and discharge. Information about drug use was assessed by the Addiction Severity Index-6th Version (ASI-6); CT was reported throughout the Childhood Trauma Questionnaire (CTQ). CTQ scores were calculated based on a latent analysis model that divided the sample into low-, medium-, and high-level trauma groups. Results: There was a significant increase in BDNF levels from admission to discharge, which did not differ across CT subgroups. For TBARS levels, we found a significant time vs. trauma interaction (F2,28 = 6.357, p = 0.005,ηp 2 = 0.312). In participants with low trauma level, TBARS decreased, while in those with a high trauma level, TBARS increased during early withdrawal. Conclusion: TBARS levels showed opposite patterns of change in crack-cocaine withdrawal according to baseline CT. These results suggest that CT could be associated with more severe neurological impairment during withdrawal.