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Biomedical subjects

W Pitchot

Publications and source records attributed to W Pitchot.

44 records · Page 3Linked to original sources
PubMed1991

The lack of relationship between DST nonsuppression in the dexamethasone suppression test and EEG abnormalities.

As a recent study suggested a relationship between cortisol escape following dexamethasone suppression test (DST) and electroencephalogram (EEG) abnormalities, we tried to replicate these findings in 52 major depressive inpatients. A total of 23 patients exhibited DST nonsuppression (44%) and 18 patients had EEG abnormalities (35%). No relationship existed between DST and EEG results.

Adult↗
PubMedDate not supplied

Psychopathological correlates of dopaminergic disturbances in major depression.

In a recent report, we confirmed the role of dopamine in the pathophysiology of depression by demonstrating a blunted response of growth hormone (GH) to apomorphine, a selective dopaminergic agonist, in endogenous depressive patients. Few data are available on the possible psychopathological correlates of disturbances in the apomorphine test. In this study, we assessed the relationship between GH response to apomorphine and the Minnesota multiphasic personality inventory (MMPI) scales in a sample of 20 major depressive inpatients. The GH response (area under the curve) after apomorphine injection was positively correlated with the social introversion scale scores (r = 0.56, df = 19, p less than 0.01) and the anxiety scale scores (r = 0.45, df = 19, p = 0.04). These results suggest dopaminergic overactivity in anxious psychopathology rather than in depressive psychopathology. The relationship between the social introversion scale score and the apomorphine test is in agreement with the dopaminergic hypothesis of schizophrenic disorders.

Adult↗
PubMedDate not supplied

[The biological basis of suicidal behavior: neuroendocrine and psychophysiological approach to the role of catecholamines].

The current main neurochemical theories of the biological correlates of suicidal behavior principally involve the serotonergic system. Few data are available about the possible role of the catecholaminergic (noradrenergic and dopaminergic) function. In the present study, in a first part, we assessed the growth hormone (GH) response to clonidine, a selective alpha 2-adrenergic agonist, and to apomorphine, a dopaminergic agonist, in 22 DSM-III-R major depressive male inpatients with a history of suicide attempts compared to 22 age-matched major depressive inpatients without history of suicidal behavior. Hormonal responses to clonidine and apomorphine were also compared with 4.00 PM postdexamethasone cortisol levels. The two groups differed significantly in the GH peak response after apomorphine: 6.27 +/- 3.18 ng/ml in suicide attempters vs 17.40 +/- 14.87 ng/ml in nonattempters (F = 11.78, p = 0.001). There was no statistically significant difference between the two groups for GH peak responses after clonidine. Moreover, mean postdexamethasone cortisol levels did not exhibit any significant difference between suicide attempters and nonattempters. Violent and nonviolent attempters did not differ on any of the biological measures. In a second part, P300 and contingent negative variation (CNV) were recorded in 20 depressive inpatients subgrouped into suicide attempters (n = 10) and nonattempters (n = 10). The results showed a significant reduction of both P300 and CNV amplitudes in patients who attempted suicide compared to patients without history of suicide attempts. Moreover, a significant correlation was found between the Suicidal Risk scale and CNV amplitude. In conclusion, these results suggest that a dopaminergic hypoactivity as assessed by a blunted GH response to apomorphine and by a reduction of both P300 and CNV amplitudes, could be considered as a biological correlate of suicidal behavior. In contrast, noradrenergic disturbances, particularly at the level of alpha 2-adrenergic receptors, seem to play a more minor role. Moreover, DST nonsuppression cannot be considered as a biological marker of suicidal behavior.

Adolescent↗