Orexin-A level elevation in recently abstinent male methamphetamine abusers.

Research has suggested that methamphetamine (METH) use influences orexin regulation. We examined the difference in orexin-A levels between METH abusers and healthy controls. Fasting serum orexin-A levels were measured in 35 participants who used METH in the preceding 3 weeks and 36 healthy controls. We found METH abusers had significantly higher orexin-A levels. No association was observed between orexin-A levels and METH use variables. Our results, consistent with prior preclinical evidence, showed that recent METH exposure is associated with increased orexin-A expression. Further investigation is required to determine whether orexin-A levels normalize after a longer term of abstinence.