Bases biologiques du comportement suicidaire: approche neuroendocrinienne et psychophysiologique du role des catecholamines.

in Acta Psychiatrica Belgica (1995), 95(4-5), 210-33

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 ... [more ▼]

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. [less ▲]

Effect of previous antidepressant therapy on the growth hormone response to apomorphine.

in Neuropsychobiology (1995), 32(1), 19-22

Several lines of evidence suggest a role for dopamine in the pathophysiology of depression. In 1988, we reported a blunted response of growth hormone (GH) to apomorphine, a dopaminergic agonist, in ... [more ▼]

Several lines of evidence suggest a role for dopamine in the pathophysiology of depression. In 1988, we reported a blunted response of growth hormone (GH) to apomorphine, a dopaminergic agonist, in endogenous depression. However, an antidepressant washout period is a major confounding factor in studies assessing the GH response to apomorphine. Indeed, whereas the influence of tricyclic antidepressants on the GH response to apomorphine is presently unknown, several reports have suggested that tricyclics may impair the GH response to clonidine for periods longer than 3 weeks following their discontinuation. In the present study, we hypothesized that a blunted GH response to apomorphine in depressed patients could be related to the recent administration of antidepressants. Therefore, the GH response to apomorphine (0.5 mg) was studied in 11 male DSM-III-R major depressive inpatients who had never received antidepressant therapy (group 1) compared to 11 normal controls and 11 major depressive inpatients drug free for at least 2 weeks (group 2). The three groups differed significantly in the GH peak response to apomorphine: mean (SD) 5.4 (4.0) ng/ml in group 1, 25.5 (10.7) in normal controls, and 5.5 (5.1) in group 2 (F = 15.5, df = 3, 30, p = 0.00001). While group 1 and normal controls (F = 21.8, p = 0.0002) as well as group 2 and controls (F = 5.6, p = 0.03) differed significantly, group 1 and group 2 did not (F = 0.18, p = 0.68). These results suggest that a washout period of 2 weeks could be sufficient in studies assessing the GH response to apomorphine. [less ▲]

Gender and diagnostic performance of the growth hormone response to clonidine for major depression : A large scale multicenter study

in American Journal of Psychiatry (The) (1994)

Relationship between alpha 2-adrenergic function and suicidal behavior in depressed patients.

in Psychiatry Research (1994), 52(2), 115-23

The current main neurochemical theories of the biological correlates of suicidal behavior involve serotonergic and, to a lesser extent, dopaminergic systems. Few data are available about the possible ... [more ▼]

The current main neurochemical theories of the biological correlates of suicidal behavior involve serotonergic and, to a lesser extent, dopaminergic systems. Few data are available about the possible implication of the noradrenergic function. In the present study, we assessed the growth hormone response to clonidine, a selective alpha 2-adrenergic agonist, in 15 DSM-III-R major depressive inpatients with a history of suicide attempts, compared with 15 age- and gender-matched major depressive inpatients without a history of suicidal behavior. Mean (+/- SD) growth hormone peak responses to clonidine were significantly lower in the group of suicide attempters than in the control group: 2.93 +/- 3.01 ng/ml vs. 8.28 +/- 8.15 ng/ml. Therefore, these results suggest that a blunted growth hormone response to clonidine could be a biological correlate of suicidal behavior. [less ▲]

Intérêt des marqueurs biologiques de dépression dans le choix du traitement antidépressif

in Médecine et Hygiène (1993)

Rôle du système dopaminergique dans la dépression.Corrélats cliniques du test à l'apomorphine

in Acta Psychiatrica Belgica (1993), 93

Role du systeme dopaminergique dans la depression: correlats cliniques du test a l'apomorphine.

in Acta Psychiatrica Belgica (1993), 93 Spec No

Disturbances in dopaminergic neurotransmission seem to play an important role in biochemical mechanisms involved in depressive disorders. The study of the growth hormone (GH) response to apomorphine, a ... [more ▼]

Disturbances in dopaminergic neurotransmission seem to play an important role in biochemical mechanisms involved in depressive disorders. The study of the growth hormone (GH) response to apomorphine, a dopaminergic agonist, provides an indirect index of dopaminergic neurotransmission at the postsynaptic level. In the present study, we assessed the role of the dopaminergic system in some psychopathological dimensions in depression: personality dimensions, suicidal behavior, psychomotor disturbances and dichotomy unipolar/bipolar. Our studies included major depressed inpatients matched for gender, age and, in the case of women, menopausal status. Our results show that dopaminergic disturbances are related to social introversion and anxiety according to dopaminergic hypothesis of schizophrenic disorders and dopaminergic hyperactivity hypothesis of anxiety disorders. A blunted GH response to apomorphine could be considered as a biological marker of suicidal behavior. Moreover motor retardation appeared to be in relationship with dopaminergic disturbances. Finally, the dopaminergic system did not appear to play a significant role in the dichotomy unipolar/bipolar. The results show the interest of the apomorphine test in the assessment of the relationship between biochemical disturbances and clinical correlates. [less ▲]

Growth hormone response to clonidine in male untreated panic patients

in Psychological Medicine (1992)

Suicidal behavior and growth hormone response to apomorphine test.

in Biological Psychiatry (1992), 31(12), 1213-9

Several cerebrospinal fluid (CSF) studies have provided support for a possible role for the dopaminergic system as a biological correlate of suicidal behavior. Indeed, low CSF levels of the dopamine ... [more ▼]

Several cerebrospinal fluid (CSF) studies have provided support for a possible role for the dopaminergic system as a biological correlate of suicidal behavior. Indeed, low CSF levels of the dopamine metabolite homovanillic acid (HVA) have been described in depressed patients with a history of suicide attempts. In this study, we assessed the dopamine receptor sensitivity in relationship to suicidal behavior by measuring growth hormone (GH) response to apomorphine 0.5 mg subcutaneously (sc) in 15 DSM-III-R (APA 1987) major depressive inpatients with a history of suicide attempts, compared to age-matched and gender-matched major depressive inpatients without a history of suicide. Patients with a history of suicidal behavior exhibited a significantly lower GH response to apomorphine than patients who never attempted suicide (t = 3.60, df = 1.28, p = 0.0012). Therefore, these results suggest that a blunted GH response to apomorphine could represent a biological marker of suicidal behavior. [less ▲]

Psychotic reactions to zolpidem.

in Lancet (1992), 339(8796), 809