Uncoupling of serotonergic and noradrenergic systems in depression: preliminary evidence from continuous cerebrospinal fluid sampling

We used the technique of continuous cerebrospinal fluid (CSF) sampling to test the following hypotheses regarding CNS monoaminergic systems in depression: (1) absolute concentrations of the informational substances tryptophan and 5-hydroxyindoleacetic acid (5-HIAA) are altered in the CNS of depressed patients (2) abnormal rhythms of tryptophan and/or 5-HIAA, or defective conversion of tryptophan to serotonin (5HT), exist in the CNS of depressed patients, and (3) the relationship between the CNS 5HT and norepinephrine (NE) systems is disrupted in depressed patients. We obtained 6-h concentration time series of tryptophan, 5-HIAA, NE, and 3-methoxy-4-hydroxyphenylglycol (MHPG) in the CSF of 10 patients with major depression and in 10 normal volunteers. No significant differences in CSF tryptophan, 5-HIAA, NE, or MHPG concentrations or rhythms were observed between normal volunteers and depressed patients. Neither were there differences in the mean tryptophan-to-serotonin ratio. However, a negative linear relationship was observed between mean concentrations of 5-HIAA and NE in the CSF of the normal volunteers (r = 0.916 [r2 = 0.839], df = 9, P < 0.001) while, in contrast, depressed patients showed no such relationship (r = +0.094 [r2 = 0.00877], df = 9, n.s.). Furthermore, the correlation coefficients expressing the relationship between CSF MHPG and CSF 5-HIAA within the normal and depressed groups were significantly different. These data support the hypothesis that a disturbance in the interaction between the serotonergic and noradrenergic systems can exist in depressive illness in the absence of any simple 5HT or NE deficit or surplus.

Thyroid and adrenal dysfunction in abstinent alcoholic men: locus of disturbance

Certain neuroendocrine abnormalities (e.g., blunted plasma adrenocorticotropic hormone [ACTH] response to corticotropin-releasing hormone [CRH] administration and blunted serum TSH response to thyrotropin-releasing hormone [TRH] administration) are common in alcoholic patients. It was the objective of this study to evaluate whether they are centrally mediated: that is, whether they are secondary to increased activity of CRH and/or TRH neurons. We evaluated the nocturnal secretion (2200 hours to 1000 hours, q 15 min) of plasma ACTH, serum cortisol, and serum TSH, and their responses to the combined administration of CRH and TRH, in 28 acutely abstinent alcoholic (age range: 32 to 57 years; mean: 42.4 years) and 19 normal men (age range: 21 to 52 years; mean: 32.1 years). To assess the validity of administering CRH and TRH simultaneously, we gave 10 additional abstinent alcoholic men (age range: 36 to 53 years; mean: 45.8 years), in random order and at least 4 days apart, either CRH, TRH, placebo, or CRH plus TRH. Nocturnal ACTH, cortisol, and TSH secretion, as well as cortisol and TSH responses after CRH plus TRH administration, were similar in alcoholic and normal men. However, ACTH peak responses to CRH plus TRH were reduced in the alcoholic men (p < 0.05). The ACTH, but not cortisol, response was greater after combined CRH plus TRH administration than after CRH alone (p < .002). The blunted ACTH response does not appear to be the result of increased endogenous CRH activity, because all parameters of nocturnal ACTH pulsatility were normal in the alcoholics. It rather appears to be secondary to an intrinsic defect in the CRH responsiveness of the pituitary corticotroph, possibly due to genetic vulnerability or to the toxic effects of prolonged alcohol abuse.

Psychiatric phenomenology in Cushing's disease

We evaluated 20 patients with Cushing's disease (i.e., Cushing's syndrome due to ACTH-secreting pituitary microadenoma) and 20 patients with Major Depressive Disorder (MDD) using the Structured Clinical Interview for DSM-III-R (SCID) and Research Diagnostic Criteria. The diagnosis of Generalized Anxiety Disorder (GAD) was most common in Cushing's disease (79%), followed by MDD (68%), and Panic Disorder (PD) including subthreshold PD (53%). The combination of MDD and GAD and/or PD was also common in Cushing's disease (63%). Behavioral symptoms, if present, usually first occurred at or after the onset of the first physical symptoms. However, the onset of PD was associated with more chronic stages of Cushing's disease. In both Cushing's disease and MDD, more female than male relatives suffered from MDD, whereas more male than female relatives suffered from substance abuse. The data demonstrate a syndrome of anxious depression in patients with active Cushing's disease; such comorbidility has not been previously noted. The data also point to intriguing epidemiological, clinical, and biological associations between Cushing's disease, MDD and substance abuse.

Adrenal function in abstinent alcoholic men

1. The nocturnal secretion of plasma ACTH and serum cortisol and their responses to ovine corticotropin-releasing hormone (oCRH) were studied in acutely abstinent alcoholic and normal men. 2. Nocturnal cortisol secretion was similar in alcoholic and normal men, but nocturnal ACTH secretion tended to be decreased during the early morning hours (0600h-0900h) in alcoholic men. ACTH, but not cortisol, responses after oCRH administration tended to be attenuated in alcoholic men. CLUSTER ANALYSIS showed that the changes were not due to alterations in ACTH pulse frequency, amplitude, or interpulse interval. 3. The data suggest an intrinsic defect in response to CRH by the pituitary corticotroph cell, possibly due to genetic vulnerability or to the toxic effects of prolonged alcohol abuse.