Pituitary gland volume among heroin users stabilised on substitution pharmacotherapy.

While long-term heroin addiction is associated with hypothalamus-pituitary-adrenal (HPA) axis dysregulation, few studies have used in vivo brain imaging to examine the impact on pituitary gland volume (PGV) or its relationship with substitution pharmacotherapy. We examined 28 heroin users stable on methadone or buprenorphine and 28 healthy controls. Heroin users exhibited larger PGVs than healthy controls, and this was particularly evident among the buprenorphine-treated group. These findings indicate that substitution pharmacotherapy may have differential effects on normalising HPA axis activity. Copyright 2010 Elsevier Ireland Ltd. All rights reserved.