The effects of serotonin3 receptor blockade on the psychobiological response to intravenous clomipramine in healthy human subjects.

BACKGROUND: The purpose of this study was to determine the role that serotonin (5-HT)3 receptors play in the prolactin and nausea responses to clomipramine challenge. METHODS: Twenty healthy subjects were randomly assigned to pretreatment with either the selective 5-HT3 receptor antagonist ondansetron, or placebo, prior to intravenous infusion with clomipramine. RESULTS: Ondansetron pretreatment had no effect on the prolactin response to clomipramine challenge. There was a trend toward decreased nausea with ondansetron pre-treatment. CONCLUSIONS: These findings are consistent with other data suggesting that 5-HT3 receptors do not play a major role in the prolactin response to 5-HT challenge in human subjects, but may mediate nausea associated with enhanced 5-HT neurotransmission.

Clomipramine challenge responses covary with Tridimensional Personality Questionnaire scores in healthy subjects.

Cloninger's Unified Biosocial Theory of Personality postulates a relationship between the relative functional activity of central serotonergic, dopaminergic, and noradrenergic neurotransmitter systems, and the strength of three elemental dimensions of personality. These dimensions are Harm Avoidance, Novelty Seeking, and Reward Dependence, respectively. Accordingly, we predicted that neuroendocrine responses to serotonergic challenge would correlate with Harm Avoidance scores, but not with Novelty Seeking or Reward Dependence scores. We examined the relationship between the prolactin and cortisol responses to a 12.5-mg intravenous clomipramine challenge and these personality dimensions as measured by Cloninger's Tridimensional Personality Questionnaire in 32 healthy subjects. The cortisol response correlated only with Harm Avoidance scores, as predicted; however, prolactin response did not correlate with Harm Avoidance scores. Instead, it demonstrated an inverse relationship with Novelty Seeking scores. There was a positive relationship of baseline prolactin with Harm Avoidance in a post hoc analysis. Cortisol response to serotonergic challenge may be a better indicator for responsivity of serotonergic systems as they relate to the personality dimension of Harm Avoidance than is prolactin. Prolactin responses may be overly affected by dopaminergic influences; however, baseline prolactin may still be a valid indicator of serotonergic tone.

The impact of an electroconvulsive therapy consultation service on ECT use at a university teaching hospital.

In order to test the hypothesis that the establishment of a centralized electroconvulsive therapy (ECT) consultation service would affect ECT use at a university teaching hospital, we retrospectively reviewed medical records of patients who received ECT during two 12-month periods preceding and following the institution of a comprehensive ECT consultation service. Data regarding ECT usage, including utilization, types of patients treated, and lengths of stay, were obtained. Patients treated after the institution of a comprehensive ECT consultation service received ECT with less delay, were discharged more quickly after the conclusion of ECT treatment, and had shorter lengths of stay compared with patients who received treatment before the initiation of the service. Following the establishment of the ECT service, the absolute number of patients who received ECT increased, although the rate of ECT use did not change. These findings suggest that the establishment of a comprehensive ECT consultation service may lead to more efficient use of this important treatment in university hospitals and to more cost-effective treatment of some patients with major depression. Additional research is necessary to explore the generalizability of these findings to other treatment settings.

Central serotonergic changes following antidepressant treatment: a neuroendocrine assessment.

We employed a neuroendocrine challenge paradigm to study the effects of antidepressant treatment on serotonergic systems in depressed patients. We compared the maximum prolactin response to intravenous clomipramine (CMI) in depressed patients who responded to antidepressant treatment to that of nonresponders. Pretreatment baseline prolactin concentrations and pretreatment prolactin responses to clomipramine challenge were not different in responders compared to non-responders. However, following antidepressant treatment, the 6 responders demonstrated a significant change in their clomipramine challenge test results, as indicated by an increase in prolactin responses. In contrast, the 7 nonresponders did not demonstrate a change in their prolactin response to clomipramine challenge following treatment. These data support the hypothesis that serotonergic system dysfunction, as manifested by blunted prolactin response to clomipramine challenge, tends to normalize after successful treatment for depression, and that abnormal serotonergic function may be a state-dependent characteristic.