Prolactin response to fentanyl in depression

Blunted prolactin response to fentanyl in depression. Normalizing effect of partial sleep deprivation

There is some evidence that sleep deprivation (SD) might exert its antidepressant properties by involving endogenous opioid mechanisms. The authors investigated the effects of mu-receptor agonist administration on prolactin release in depressed patients before and after partial SD. Medication-free female depressed inpatients (N=18) were participating in two fentanyl challenge tests after partial SD and undisturbed sleep, 3 days apart in random order. Healthy volunteer women (N=10) were enrolled after full night sleep as comparison subjects. Five of them had placebo trials. Participants were given an intravenous injection of 0.1 mg/70 kg fentanyl at 9:00 AM. The prolactin secretory response to the opiate agonist was investigated for 1 h with serial blood sampling. After a night of undisturbed sleep, fentanyl administration prompted increases in plasma prolactin concentrations with blunted responses found in the depressed group. Following partial SD, the stimulated prolactin secretion of depressed patients increased significantly and was comparable to the response of comparison subjects. These findings suggest that SD acts via an opioid/dopamine-related mechanism. An alternative explanation, based on serotonin involvement is addressed in the discussion.

Opiate sensitivity test in patients with stereotypic movement disorder and trichotillomania

Preliminary data about the therapeutic effect of opiate receptor manipulation in self-injurious behavior (SIB) suggest that endogenous opioid mechanisms may have a pathophysiological role in that condition and their involvement may be dependent on the severity of the SIB. The aim of this study was to use fentanyl-induced prolactin response as an opiate receptor sensitivity test in patients with stereotypic movement disorder (SMD) manifesting SIB (skin picking). Healthy volunteers and trichotillomanic patients were enrolled as comparison subjects. Individuals with trichotillomania (TTM) manifest repetitive, less serious self-mutilation (hair pulling) and are classified under different DSM-IV category than SMD. Therefore, they were considered as patient controls. Ten healthy subjects received 0.05 mg/70 kg and another 10 were given 0.1 mg/70 kg dose of fentanyl intravenously in the AM hours. Five of them had placebo trials. A dose of 0.05 mg/70 kg fentanyl was administered to patients with SMD (n = 10) and TTM (n = 12). Serial blood sampling was performed for prolactin measurements. Fentanyl elevated plasma prolactin in a dose-dependent manner. Patients with skin picking, but not with hair pulling, showed significantly increased responses. This finding supports the involvement of endogenous opioids in the pathomechanism of serious SIB.

Endogenous opiates: 1989

This paper is the twelfth installment of our annual review of the research published during 1989 involving the behavioral, nonanalgesic, effects of the endogenous opiate peptides. The specific topics this year include stress; tolerance and dependence; eating; drinking; gastrointestinal and renal functions; mental illness; learning, memory, and reward; cardiovascular responses; respiration and thermoregulation; seizures and other neurological disorders; electrical-related activity; locomotor activity; sex, development, pregnancy, and aging; immunological responses; and other behavior.