Psychiatry research
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Psychiatry research · Dec 1998
Effects of specific dopamine D1 and D2 receptor antagonists and agonists and neuroleptic drugs on emotional defecation in a rat model of akathisia.
An increase in emotional defecation in rats in a well-habituated environment induced by neuroleptic drugs (NDef) has been proposed as a model for neuroleptic-induced akathisia. We examined the effects of dopamine receptor antagonists and agonists on this model. A selective dopamine D1 antagonist (SCH 23390) and a selective D2 antagonist (raclopride) induced increased defecation at higher doses, and demonstrated a synergistic effect at lower doses. ⋯ The results of our studies suggest that NDef is most probably an effect of central dopamine antagonism that is not specific to D1 or D2 receptors, but that the two receptor subtypes have a synergistic effect. It is unlikely to be due to actions of neuroleptics on 5HT2 or alpha1 receptors as has sometimes been suggested. The results have implications for our understanding of the pathogenesis of akathisia.
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Neuroanatomical studies suggest a close interrelationship between brainstem centers regulating arousal and pain sensitivity. Nervousness, as assessed with a Visual Analog Scale, and pain sensitivity, as assessed with a cold pressor test, were used to clarify whether a physiological association of nervousness and pain sensitivity can be found in healthy subjects. Forty healthy volunteers were included in the study. ⋯ These data suggest that there is a coupling between nervousness and endogenous pain control. Based on the results, a nervousness-pain-threshold quotient was calculated as a possible measure of the interrelationship of the endogenous pain control system to autonomic activity. A different nervousness-pain-threshold quotient, indicating a different coupling, may provide information on changes in accessory neurophysiologic functions.
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Psychiatry research · May 1997
Pain assessment in self-injurious patients with borderline personality disorder using signal detection theory.
Signal detection theory measures of thermal responsivity were examined to determine whether differences in reported pain experienced during self-injurious behavior in female patients with borderline personality disorder (BPD) are explained by neurosensory factors and/or attitudinal factors (response bias). Female patients with BPD who do not experience pain during self-injury (BPD-NP group) were found to discriminate more poorly between noxious thermal stimuli of similar intensity, low P(A), than female patients with BPD who experience pain during self-injury (BPD-P group), female patients with BPD who do not have a history of self-injury (BPD-C group), and age-matched normal women. The BPD-NP group also had a higher response criterion, B (more stoical) than the BPD-C group. These findings suggest that 'analgesia' during self-injury in patients with BPD is related to both neurosensory and attitudinal/psychological abnormalities.
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Psychiatry research · Sep 1996
Diaphoresis and dehydration during neuroleptic malignant syndrome: preliminary findings.
Serum osmolality and its relationship to diaphoresis and polydipsic behavior were examined in a series of 38 episodes of neuroleptic malignant syndrome (NMS) in 29 patients. Clinical variables were associated with significantly higher serum osmolality, and diaphoresis tended to emerge earlier than polydipsia in the course of NMS. The findings of this study are consistent with the hypothesis that, at least in some NMS patients, diaphoresis leads to dehydration followed by physiologically appropriate thirst and increased oral water intake. It appears that intravenous hydration is often necessary to correct the significant free water deficit that can occur during the course of NMS.
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Psychiatry research · May 1996
Randomized Controlled Trial Comparative Study Clinical TrialCircadian rhythms of prolactin and thyroid-stimulating hormone during the menstrual cycle and early versus late sleep deprivation in premenstrual dysphoric disorder.
The present study extended previous work by examining whether disturbances in the circadian rhythms of prolactin (PRL) and thyroid-stimulating hormone (TSH) distinguish patients with premenstrual dysphoric disorder (PMDD) from normal volunteers. In addition, the effects of therapeutic interventions with early and late partial sleep deprivation were explored. Both PRL and TSH levels were measured every 30 min from 18:00 h to 09:00 h during midfollicular and late luteal menstrual cycle phases in 23 PMDD patients and 18 normal volunteers. ⋯ PRL levels decreased and TSH levels increased with sleep deprivation compared with baseline conditions. The timing of PRL secretion shifted earlier with late sleep deprivation and later with early sleep deprivation. Although circadian disturbances of PRL and TSH were found in PMDD patients compared with normal volunteers, the therapeutic effects of early and late sleep deprivation do not appear to be mediated by correcting these disturbances.