The dexamethasone suppression test in panic disorder and major depressive episodes

Le test de stimulation par le corticotrophin-releasing factor chez les patients présentant des attaques de panique

Les convergences épidémiologiques, cliniques et biologiques, entre trouble panique et dépression laissent à penser que ces 2 phénomènes pourraient être sous-tendus par un même mécanisme physiopathologique. Des travaux récents retrouvent chez des patients présentant un trouble panique une diminution de la réponse de l'ACTH à la stimulation par le CRF (corticotropin-releasing factor) exogène comparable à celle observée dans la population des déprimés endogènes. Ces résultats suggèrent l'existence dans le trouble panique, comme dans la dépression, d'un hyperfonctionnement de l'axe hypothalamo-hypophyso-surrénalien sous l'influence d'une hypersécrétion de CRF endogène. Afin de vérifier cette hypothèse, les auteurs ont pratiqué un test de stimulation par le CRF et un test de freinage par la dexaméthasone (DST) chez 10 patients non déprimés présentant un trouble panique ou une agoraphobic avec attaques de panique. Les résultats du DST n'apparaissent pas différents de ceux habituellement retrouvés chez le sujet sain. La comparaison des taux de base de Cortisol et d'ACTH retrouvés dans le groupe « panique » et chez 7 sujets témoins ne montre pas de différence. Enfin, si la réponse du Cortisol à la stimulation par le CRF exogène n'apparaît pas significativement différente de celle observée chez les témoins, on note une augmentation de la réponse de l'ACTH chez les sujets présentant des attaques de panique. Ces résultats sont en contradiction avec ceux des travaux précédemment cités et semblent infirmer l'existence dans les troubles anxieux paroxystiques d'une hypersécrétion chronique de CRF endogène. Ces discordances peuvent, certes, peut-être s'expliquer par des différences dans les populations étudiées et dans les méthodes utilisées. L'augmentation de la réponse de l'ACTH à la stimulation par le CRF exogène observée dans cette étude chez les patients présentant des attaques de panique se montre cepcndant compatible, contrairement aux autres travaux, avec les théories habituellement admiscs et impliquant une hyperactivité noradrénergique centrale dans l'étiopathogénie des troubles anxieux.

Investigation of cortisol levels in patients with anxiety disorders: a structured review

Anxiety disorders are common and distressing medical conditions, which typically arise in adolescence or early adult life. They can persist for many years, reducing quality of life, limiting academic and occupational achievement, and being responsible for considerable economic pressures. Although a range of psychological and pharmacological treatments are available, their success is often limited, and many patients remain troubled by significant symptom-related disability for long periods. The detailed pathophysiology of each anxiety disorder is not established, and novel treatments that are based solely on current understanding of conventional neurotransmitter function are unlikely to be substantially more effective or better tolerated than current treatments. Investigations of hypothalamo-pituitary axis function across panic disorder, generalized anxiety disorder, specific phobias and social anxiety disorder have produced intriguing findings but not revealed a consistent pattern of endocrine disturbance, perhaps reflecting differences in methodology and the nature and size of the clinical samples. There is a persistent need for large, prospective studies using standardized methods for investigation and data analysis (164 words).

[Contributions of cortisol suppression tests to understanding of psychiatric disorders: a narrative review of literature]

Activity of the hypothalamic-pituitary-adrenal axis had been studied for the past half century, when some researchers noted that some patients with Cushing's syndrome and severe mood disorders had high baseline cortisol levels, which resulted in an inhibited response in the 1mg dexamethasone suppression test. Altered dexamethasone suppression test results were subsequently found in many psychiatric diseases, including anorexia nervosa, obsessive-compulsive disorder, degenerative dementia, bipolar disorders, and schizophrenia. The relationship between high baseline cortisol levels and stress has also been studied. Some researches on the genesis of borderline personality disorder focused on traumatic childhood backgrounds. Other investigations aimed at elucidating the relationship between traumatic backgrounds and some psychiatric disorders noted that patients with post-traumatic stress disorder and borderline personality disorder showed an enhanced cortisol suppression with low cortisol doses (0.5 mg). Recent studies showed that use of an ultra-low dose of cortisol during the dexamethasone suppression test may be helpful for detecting disorders with hyperactivity of the hypothalamic-pituitary-adrenal axis. Recent advances in neuroimaging support the existence of hyperactivity of the hypothalamic-pituitary-adrenal axis in patients with borderline personality disorder, relating a decreased pituitary gland volume to major traumatic backgrounds and suicidal attempts. The purpose of this paper is to make a narrative review of research using dexamethasone suppression test in psychiatric disorders, in order to ascertain its value as a supplemental diagnostic test or as a prognostic marker.

Normal urinary free cortisol and postdexamethasone cortisol in social phobia: comparison to normal volunteers

In primates, social stress is associated with activation of the hypothalamic-pituitary-adrenal (HPA) axis. Social phobia is a common, often disabling, form of pathological anxiety characterized by marked distress in situations involving possible scrutiny or evaluation. Little is known about HPA function in patients with social phobia. We examined 24-hour excretion of urinary free cortisol (UFC) in 54 patients with social phobia and post-dexamethasone cortisol levels in 64 patients with social phobia and found no evidence of HPA-axis overactivity compared to normal controls, despite pathological levels of anxiety.

Glucocorticoid receptor number and cortisol excretion in mood, anxiety, and psychotic disorders

In the present study, we measured cytosolic lymphocyte glucocorticoid receptor and 24-hour urinary cortisol excretion in patients with major depressive disorder, bipolar mania, posttraumatic stress disorder, panic disorder, and schizophrenia. Patients with major depression had the smallest, and posttraumatic stress disordered patients the largest, mean number of glucocorticoid receptors per cell compared to patients in the other groups. Bipolar manic and panic patients did not differ from each other in regard to the number of lymphocyte glucocorticoid receptors. Bipolar manic and panic patients did have significantly more glucocorticoid receptors/cell than schizophrenic patients. The mean 24-hour urinary cortisol excretion was significantly higher in patients with major depression and bipolar mania than in those in the other diagnostic groups. Lymphocyte glucocorticoid receptor number and cortisol excretion tended to be inversely related, when the entire sample was considered as a whole, but this effect did not reach statistical significance. It is concluded that lymphocyte glucocorticoid receptors may be modulated by multiple influences, not just ambient cortisol levels. These preliminary data suggest that the assessment of lymphocyte glucocorticoid receptor number in tandem with cortisol levels may provide a more meaningful estimate of hypothalamic-pituitary-adrenal axis activity than is achieved using cortisol alone.

Higher postdexamethasone serum cortisol levels in agoraphobic than in nonagoraphobic panic disorder patients

The dexamethasone suppression test (DST) was performed in panic disorder (PD) patients with (n = 32) or without (n = 31) agoraphobia and in normal controls (n = 49). Postdexamethasone serum cortisol levels were significantly higher in agoraphobic PD patients (105.3 +/- 19.3 nmol/L) both when compared to PD patients without agoraphobia (47.3 +/- 7.7 nmol/L; p less than 0.01) and when compared to healthy controls (51.7 +/- 8.3 nmol/L; p less than 0.01). The rate of nonsuppressors (i.e., subjects displaying postdexamethasone cortisol levels greater than 138 nmol/L) was 28% and 3% in agoraphobic and nonagoraphobic PD patients, respectively, and 12% in controls. In patients, the postdexamethasone cortisol levels did not correlate with the number of panic attacks per week, baseline anxiety as measured using the Hamilton Anxiety Scale, depressive symptoms as measured using the Montgomery-Asberg Depression scale, or duration of illness. Data from eight patients in whom a second DST was performed after treatment with imipramine or clomipramine for three months indicate that a marked reduction of the number of anxiety attacks is not necessarily accompanied by a normalization of a pathological DST. In conclusion, it is suggested that the elevated postdexamethasone cortisol levels sometimes observed in agoraphobic PD patients are more closely related to the agoraphobic behavior than to the panic attacks per se.

Behavioral biochemical and neuroendocrine concomitants of lactate-induced panic anxiety

In a single-blind study using sodium lactate infusions to provoke panic attacks, 11 of 15 patients with panic disorder panicked with lactate. None of the 15 control subjects panicked during lactate administration. Before receiving lactate, higher preinfusion anxiety levels were present in the patient group as compared to controls. Preinfusion Acute Panic Inventory (API) scores were significantly higher in patients who panicked compared to nonpanicking patients. In addition, patients who panicked during lactate infusion showed a higher mean plasma MHPG level at baseline. During lactate infusion, however, no increase in plasma MHPG was seen in patients who panicked, nor in nonpanickers and controls. Several other biochemical and hormonal variables were measured. No single biochemical or neuroendocrine variable was found to correlate with lactate-induced panic attacks. It is argued that the baseline arousal level of patients with panic disorder may be increased, which renders these patients more vulnerable to panic attacks.

The significance of HPA axis disturbance in panic disorder

Agoraphobic and panic disorder patients underwent 1-mg Dexamethasone Suppression Tests (DST) before, during, and after an 8-week trial of diazepam, alprazolam, or placebo. Previously described, never-ill controls underwent similar testing. At baseline, 21 of 82 (25.6%) panic disorder and 5 of 38 (13.2%) controls were nonsuppressors. This difference grew more marked with multiple testing over a 2-month period; 18 of 44 (40.9%) panic disorder patients were nonsuppressors on at least 1 of 3 tests compared with only 5 of 35 (14.3%) controls (p = 0.006). DST results were related to severity, but not to the presence or absence, of depressive syndromes. Control for plasma dexamethasone levels left highly significant differences in postdexamethasone cortisol across diagnostic groups. Neither DST results nor plasma dexamethasone levels changed in concert with clinical change, and type of treatment had little differential effect on these measures. Nor did DST results predict subsequent course when active treatment was extended by 6 months. However, DST results during the initial 8 weeks of treatment were strongly related to relapse when medications were tapered, even though this occurred 6 months after the last DST.

HPA axis disturbance and treatment outcome in panic disorder

Some patients with panic disorder exhibit an abnormal response to dexamethasone. As this phenomenon may reflect disturbances in the central noradrenergic system and as alprazolam may work through this system to produce improvement, we predicted a particularly robust response among nonsuppressors. Fifty-two patients with panic disorder or with agoraphobia with panic attacks were given alprazolam as the sole treatment during either of 2, 8-week, double-blind, placebo-controlled trials. Though baseline clinical severity predicted globally rated outcome, baseline Dexamethasone Suppression Test results did not.

Cortisol response to clonidine in panic disorder: comparison with depressed patients and normal controls

Abnormalities in regulation of noradrenergic function have been proposed as part of the pathology of depressive and panic anxiety disorders. However, abnormalities in hypothalamic-pituitary-adrenal (HPA) axis function have largely been limited to patients with depressive disorders. Using the cortisol response to clonidine, an alpha 2-adrenergic receptor agonist, this study examined the relationship between the noradrenergic system and the HPA axis in 10 patients with major depression (4 unipolar, 6 bipolar), 10 patients with panic disorder, and 10 normal controls. Baseline cortisol was significantly elevated in depressed as compared with panic patients, but not with controls. Depressed patients also tended to exhibit a greater absolute fall in plasma cortisol (5.2 +/- 4.0 micrograms/dl) compared with panic patients (1.7 +/- 2.4 micrograms/dl) (p less than 0.06, t-test). When expressed as a percentage of baseline, however, the cortisol response to clonidine did not differ significantly between diagnostic groups (p greater than 0.10). Basal levels of cortisol were highly correlated with the degree of decrease in cortisol induced by clonidine in the group of 30 subjects (r = -0.81, p less than 0.0001). These findings are discussed in the context of the utility of clonidine as a probe of the functional relatedness of the noradrenergic system and the HPA axis in these disorders.

Altered plasma dexamethasone and cortisol suppressibility in patients with panic disorders

Some abnormalities in the hypothalamic-pituitary-adrenal (HPA) axis in patients with panic disorders were recently reported. The possibility that the disposition of dexamethasone, which has been reported to influence the Dexamethasone Suppression Test (DST), might be altered in this subgroup of patients has not, as yet, been reported. We report that 4:00 PM dexamethasone plasma concentrations following a 1-mg oral DST were significantly (p less than 0.01) lower in 23 patients with panic disorders (0.49 +/- 0.44 ng/ml) compared to 52 normal control subjects (1.09 +/- 0.64 ng/ml). This is in addition to the significantly higher (p less than 0.05) 4:00 PM postdexamethasone cortisol values per nanogram per milliliter of dexamethasone in the panic disorder patients compared to normal controls (17.7 +/- 29.6 versus 5.0 +/- 11.2 micrograms/dl). The mean percent suppression of cortisol from baseline in panic disorder was normal despite one-half the dexamethasone concentrations in these subjects. The cortisol suppression versus dexamethasone concentration curve was also shifted lower (greater fraction of cortisol suppression) and to the left (toward lower dexamethasone concentrations). These results further suggest that the HPA system is indeed altered in panic disorders, but in a manner that is not readily apparent from the DST alone.

Normal urinary free cortisol and plasma MHPG in panic disorder: clinical and theoretical implications

Abnormalities of the hypothalamic-pituitary-adrenal (HPA) axis and noradrenergic function have been reported in patients with panic disorder. Mean urinary free cortisol and plasma MHPG were measured in 12 medication-free panic disorder patients and 12 normal controls. No significant difference in urinary free cortisol and plasma MHPG was observed between the patients and controls. There was no relationship between plasma MHPG and urinary free cortisol in the panic patients or normal controls. These findings are described within the context of current concepts of stress and noradrenergic dysfunction in panic disorder.

Dexamethasone suppression test and coping behavior in psychosocial stress

The dexamethasone suppression test (DST) and the Minnesota Multiphasic Personality Inventory (MMPI) were administered to 144 healthy inductees on day 2 of military service. One hundred and four of them completed a 120-item questionnaire describing their coping responses to this particular challenge. Thirty-six subjects (25%) failed to suppress plasma cortisol adequately. Their mean scores on the MMPI clinical standard scales were within the normal range. High postdexamethasone cortisol levels were associated with denial and passivity, and with low demand for social support. These results suggest that the DST might be more related to coping with a stressor than to a specific diagnosis. The authors speculate that high hypothalamic-pituitary-adrenal activity may have a primary role in psychological defense promoting inattention to the aversive aspects of stressful situations.

The dexamethasone suppression test and plasma dexamethasone in generalized anxiety disorder

A Dexamethasone Suppression Test nonsuppression rate of 27% was found in a group of 30 generalized anxiety disorder patients before treatment. The dexamethasone concentrations in the eight nonsuppressors were significantly lower than in eight suppressors matched by sex and age, but were similar to those in five nonsuppressors from a matched normal control group. The dexamethasone concentrations in the generalized anxiety disorder suppressors and a matched group of eight normal control suppressors were similar. After successful nondrug behavioral treatment, all generalized anxiety disorder patients were suppressors. Posttreatment dexamethasone concentrations in the initial nonsuppressor patients remained significantly lower than in the initial suppressors. The results suggest that low plasma dexamethasone concentrations after 1 mg oral dexamethasone may confer a vulnerability to nonsuppression that may be expressed in the presence of high state anxiety.