Association of biogenic amine metabolites with symptomatology in delusional (psychotic) and nondelusional depressed patients

Neuromolecular Etiology of Bipolar Disorder: Possible Therapeutic Targets of Mood Stabilizers

Bipolar disorder is a mental illness that causes extreme mood swings and has a chronic course. However, the mechanism by which mood episodes with completely opposite characteristics appear repeatedly, or a mixture of symptoms appears, in patients with bipolar disorder remains unknown. Therefore, mood stabilizers are indicated only for single mood episodes, such as manic episodes and depressive episodes, and no true mood-stabilizing drugs effective for treating both manic and depressive episodes currently exist. Therefore, in this review, therapeutic targets that facilitate the development of mood stabilizers were examined by reviewing the current understanding of the neuromolecular etiology of bipolar disorder.

Urinary sampling for 5HIAA and metanephrines determination: revisiting the recommendations

CONTEXT

Biogenic amines such as 5-hydroxy-indole acetic acid (5HIAA) the main metabolite of serotonin or metanephrines (catecholamines metabolites) are used as biomarkers of neuroendocrine tumours.

OBJECTIVE

To re-evaluate the recommendations for urinary sampling (preservatives, diet, drugs, etc.) as many of the reported analytical interferences supporting these recommendations are related to obsolete assays.

METHODS

Bibliographic analysis of old and modern assays concerning preservation, extraction, assay and interferences.

RESULTS

5HIAA may degrade as soon as urine is excreted. Thus, acids as preservatives (hydrochloric or acetic acid) have to be immediately added. Care should be taken not to decrease the pH under 2. Urine preservative for metanephrine assays is not mandatory. Diets including serotonin-, tryptophan- and dopamine-rich foods have to be avoided depending on the biomarkers investigated (bananas, plantain, nuts, etc.). Tryptophan-rich over-the-counter formulas have to be prohibited when 5HIAA has to be assayed. Acetaminophen may interfere with electrochemical detection depending on high-pressure liquid chromatography (HPLC) parameters. No interference is known with mass spectrometric assays but with the one described for metanephrines determination. Some drugs interfere however with serotonin and catecholamines secretion and/or metabolism (monoamine oxidase inhibitors, serotonin or dopamine recapture inhibitors, etc.).

CONCLUSION

Revisited recommendations are provided for the diet, the drugs and the preservatives before HPLC coupled with electrochemical and mass spectrometry assays.

Endocrine withdrawal syndromes

Hypersecretion of endogenous hormones or chronic administration of high doses of the same hormones induces varying degrees of tolerance and dependence. Elimination of hormone hypersecretion or discontinuation of hormone therapy may result in a mixed picture of two syndromes: a typical hormone deficiency syndrome and a generic withdrawal syndrome. Thus, hormones with completely different physiological effects may produce similar withdrawal syndromes, with symptoms and signs reminiscent of those observed with drugs of abuse, suggesting shared mechanisms. This review postulates a unified endocrine withdrawal syndrome, with changes in the hypothalamic-pituitary-adrenal axis and the central opioid peptide, in which noradrenergic and dopaminergic systems of the brain act as common links in its pathogenesis. Long-term adaptations to hormones may involve relatively persistent changes in molecular switches, including common intracellular signaling systems, from membrane receptors to transcription factors. The goals of therapy are to ease withdrawal symptoms and to expedite weaning of the patient from the hormonal excess state. Clinicians should resort to the fundamentals of tapering hormones down over time, even in the case of abrupt removal of a hormone-producing tumor. In addition, the prevention of stress and concurrent administration of antidepressants may ameliorate symptoms and signs of an endocrine withdrawal syndrome.

Impairments in working memory associated with naturalistic dieting in women: no relationship between task performance and urinary 5-HIAA levels

The present study investigated the question of whether the previously observed impairments of working memory characteristic of dieting to lose weight can be explained in terms of preoccupying cognitions relating to body shape or to alterations in serotonergic function resulting from a low dietary intake of tryptophan. The population comprised female non-dieting, lower restrained eaters (N=23), non-dieting higher restrained eaters (N=11) and current dieters (N=19). Each participant completed three tasks, each of which selectively loaded on to a different sub-component of working memory. The tasks comprised the Tower of London task, a letter string recall task and a mental rotation task. In addition, all participants completed self-report measures of body shape concern and affective state. Serotonin turnover was assessed by means of 24 h urine sample collection for each participant on their day of testing. This was analysed (via HPLC) for levels of the main serotonin metabolite 5-HIAA.The results of the present study broadly replicated previous findings of a Central Executive and Phonological Loop (but not Visuo-Spatial Sketchpad) deficit in those subjects who reported themselves to be currently dieting. Tower of London task performance also significantly correlated with self-reported feelings of fatness and body shape disparagement. There were no group differences in 5-HIAA levels nor did 5-HIAA levels correlate with task performance. However, there was a significant negative correlation between 5-HIAA levels and self-reported depression. These results support the hypothesis that the variables mediating this deficit are preoccupying cognitions concerning body shape. They do not support the hypothesis that the serotonergic function of dieters is compromised, although this conclusion is tentative.