Mood and neuroendocrine response to a chemical stressor, metyrapone, in buprenorphine-maintained heroin dependence.
BACKGROUND
Heroin dependence is associated with a hyperactive hypothalamic-pituitary-adrenal (HPA) axis, proposed as a biological correlate of craving. Maintenance treatment with methadone normalizes HPA axis activity. Here, we examined HPA axis activity under maintenance treatment with the increasingly utilized partial opiate agonist buprenorphine.


METHODS
Responses to a metyrapone challenge were compared in 20 buprenorphine-maintained heroin addicts and 20 healthy volunteers (10 received a single 50 mg naltrexone dose [NTX+] and 10 received no naltrexone [NTX-]). Patients were 16 male subjects and 4 female subjects, aged 30 to 38 years, heroin-dependent and relapse-free under buprenorphine maintenance (BUP) for a minimum of 6 months. Healthy volunteers were 9 male subjects and 11 female subjects, aged 36 to 49 years, with no history of dependence. Serial measures were obtained of plasma adrenocorticotropic hormone (ACTH) and cortisol and Profile of Mood States (POMS) ratings over time. Subjects were genotyped for the OPRM1 118A/G polymorphism.


RESULTS
Buprenorphine maintenance showed a dampened HPA axis response to metyrapone, with OPRM1 118G carriers showing a significantly attenuated response compared with 118A carriers. The response of the NTX+ group was markedly increased. In contrast, negative affect was elevated in the BUP group but did not differ between NTX- and NTX+. Buprenorphine maintenance and NTX- groups did not differ in positive affect, whereas the NTX+ group was lower.


CONCLUSIONS
In contrast to exaggerated HPA axis responsiveness reported in untreated heroin dependence, response to metyrapone was subnormal in heroin addicts maintained on buprenorphine. Despite this, increased measures of negative affect were seen in this group. This implies a dissociation of HPA axis responsiveness and affect in heroin dependence.
Kakko
Johan
J
Department of Clinical Neuroscience, Karolinska Institute, Stockholm, Sweden.
von Wachenfeldt
Joachim
J
Svanborg
Kerstin Dybrandt
KD
Lidström
Jessica
J
Barr
Christina S
CS
Heilig
Markus
M
D000328:Adult; D000339:Affect / Q000187:drug effects*; D001216:Asparagine / Q000235:genetics; D002047:Buprenorphine / Q000008:administration & dosage; D004252:DNA Mutational Analysis / Q000379:methods; D004347:Drug Interactions; D004791:Enzyme Inhibitors / Q000627:therapeutic use*; D005260:Female; D006556:Heroin Dependence / Q000188:drug therapy* / Q000235:genetics / Q000503:physiopathology / Q000523:psychology; D006801:Humans; D007030:Hypothalamo-Hypophyseal System / Q000187:drug effects*; D008297:Male; D008797:Metyrapone / Q000627:therapeutic use*; D008875:Middle Aged; D009271:Naltrexone / Q000008:administration & dosage; D009292:Narcotic Antagonists / Q000008:administration & dosage; D010913:Pituitary-Adrenal System / Q000187:drug effects*; D020641:Polymorphism, Single Nucleotide; D017450:Receptors, Opioid, mu / Q000235:genetics; D013997:Time Factors
D004791:Enzyme Inhibitors; D009292:Narcotic Antagonists; C485764:OPRM1 protein, human; D017450:Receptors, Opioid, mu; D002047:Buprenorphine; D009271:Naltrexone; D001216:Asparagine; D008797:Metyrapone