Platelet MAO activity and the cortisol response to dexamethasone in major depression

Panic disorder: Psychobiological aspects of personality dimensions

Attempts to understand the underlying mechanisms of association between psychological factors and panic disorder have been mostly based on psychodynamic description. Evidence of the importance of serotonergic (5-HT) system in panic disorder (PD), however, has substanti ally increased in recent years. OBJECTIVE The objective of our study was to determine whether there was a specific personality profile of panic disorder patients and how it was related to possible neurobiological mechanisms underlying personality dimensions. PATIENTS AND METHODS Sample consisted of 14 inpatients with ICD-X diagnosis of panic disorder and 34 healthy control subjects. Personality dimensions were assessed by Minnesota Multiphasic Personality Inventory (MMPI-201) and Tridimensional Personality Questionnaire (TPQ). To assess central 5-HT function, platelet monoamine-oxidase (MAO) activity was measured. RESULTS In panic disorder group, higher scores of histrionic, depressive and hypochondriac subscales and significant increase of harm avoidance (HA) scale as well as low MAO activity were found. Negative correlation was established between MAO activity and psychopathic deviance MMPI scale. CONCLUSION The obtained results might indicate a specific personality profile of patients with panic disorder, which is characterized by high neuroticism, fearfulness, inhibition, shyness and apprehensive worry. Low MAO activity and high HA scores possibly indicate underlying hyperserotonergic state. The observed correlation between personality traits and MAO activity provide additional support for the hypothesized functional relationship between underlying central monoaminergic activity and temperament traits associated with anxiety, depression and impulsivity.

Biological parameters in major depression: effects of paroxetine, viloxazine, moclobemide, and electroconvulsive therapy. Relation to early clinical outcome

BACKGROUND

Clinical and pharmacologic studies report a relative or absolute serotonergic deficiency in major depression; however, the variability of clinical characteristics of illness has led to controversial results. In the present work, we looked for a possible relationship between i) biochemical values that indirectly reflect aminergic neurons activity and clinical characteristics and ii) their evolution and the early clinical outcome under antidepressive therapies (ATs).

METHODS

Platelet serotonin content, platelet monoamine oxydase activity, and urinary biopterins were measured in 27 depressed patients before and during four different ATs (paroxetine, viloxazine, moclobemide, or electroconvulsive therapy). Depressive symptomatology and its evolution under ATs were quantified using three clinical rating scales.

RESULTS

A severe symptomatology, high serotonin (5-HT) platelet content, and high or low urinary B could represent risk factors leading to a smaller or delayed response to an AT. Furthermore, the early improvement under ATs was negatively correlated to pretreatment 5-HT platelet content.

CONCLUSIONS

Determination of 5-HT level could be useful in the choice of an AT.

Platelet MAO activity in patients with dysthymic disorder

The aim of the present study was to examine possible associations between platelet monoamine oxidase (MAO) activity and primary dysthymic disorder. For that purpose we estimated the enzyme activity in 58 patients (15 males and 43 females) selected according to DSM-III-R criteria and in 61 healthy controls (30 males and 31 females). Platelet MAO activities were found significantly lower in the female patients compared to female controls. Moreover, the enzyme activities were found to be even lower in the female patients who had attempted suicide. These differences did not exist in the male population. We could not find any associations of MAO activity to the age of the patients, the age of onset, the duration of dysthymia, or HAM-D and SCL-90R scores. Our findings are consistent with the hypothesis that platelet MAO activity is a trait-dependent indicator of vulnerability to dysthymic disorder and suicidality in our female population.

Classification of patients with affective disorders using platelet monoamine oxidase activity, serum melatonin and post-dexamethasone cortisol

Platelet monoamine oxidase activity (MAO), melatonin and cortisol post-dexamethasone suppression test (DST) were examined in 28 patients with major affective disorder and in 20 controls. MAO activity was lower and cortisol post-dexamethasone was higher in depressed patients. Platelet MAO activity and cortisol in depressed and controls yielded high sensitivity (90%) and specificity (89%). The patients were re-examined after 10 years and categorized into affective psychosis or neurotic depression (ICD-9). Multidimensional analysis identified one subgroup coinciding in 92% with affective psychosis and another subgroup coinciding in 87% with neurotic depression. Combination of MAO, melatonin and post-DST cortisol may be useful in the diagnosis of subgroups of depressed patients and in choice of therapy.

Primary early onset dysthymia, biochemical correlates of the therapeutic response to fluoxetine: I. Platelet monoamine oxidase and the dexamethasone suppression test

A subgroup of primary dysthymic patients have been reported to respond to traditional antidepressants and, more recently, to the newer serotonergic agents. Two putative biological markers of affective illness, platelet monoamine oxidase (MAO) activity and plasma cortisol levels following dexamethasone administration, were explored for their diagnostic and predictive potential in dysthymia. Compared to controls, patients had significantly lower platelet MAO activity. Among patients, those that responded to treatment with the serotonergic agent, fluoxetine, had lower pretreatment MAO activity than nonresponders. Higher pretreatment plasma cortisol levels following dexamethasone were also associated with a positive treatment response to this medication. These findings support the view that there is a biological substrate for some subgroups of dysthymics. This biological component may involve the hypothalamic pituitary adrenal axis and serotonergic system(s).

Monoamine oxidase and cortisol response in depression and schizophrenia

The relationship between hypothalamic-pituitary-adrenal (HPA) axis function and platelet monoamine oxidase (MAO) activity was examined in drug-free depressed (n = 32) and schizophrenic (n = 36) inpatients. HPA function was measured by determining plasma cortisol levels at 8:30 a.m. and 11 p.m. before, and 8:30 a.m., 4 p.m., and 11 p.m. after administration of 1 mg of dexamethasone (DEX). There was a significant correlation between platelet MAO activity and all post-DEX cortisol levels (8:30 a.m., 4 a.m., and 11 p.m.) in depressed patients, and MAO activity and pre-DEX cortisol levels (11 p.m.) in schizophrenic patients. MAO activity was significantly higher in depressed DST nonsuppressors than in suppressors, and there were more DST nonsuppressors in high-MAO groups as compared with low-MAO groups. Our results thus suggest a strong relationship between platelet MAO activity and HPA function in depressed patients. These biochemical markers are potentially useful in the identification of biochemically and clinically homogeneous subgroups of depressed patients.

Depression and acute myocardial infarction: a review and reinterpretation

Depression is widely accepted as occurring in response to acute myocardial infarction (AMI), and to be an important determinant of recovery. A review of the literature reveals that three categories of patients with depressive symptomatology may be identifiable. First, many patients show depressive symptoms before admission with AMI; these may intensify during hospitalisation. For these patients, the depressive symptoms may contribute etiologically to the onset of AMI or derive from a common source along with AMI. The second group constitute patients with a history of AMI, and who on readmission with chest pain or suspected AMI are more likely to report depressive symptoms. The third group of patients are non-depressed first time admissions for AMI. These patients appear to show transient depressive reactions, much of which it is argued, occurs as a reaction to hospitalisation and not to AMI per se. This review considers the theoretical context whereby depressive symptoms may arise from the same circumstances that generate the coronary heart disease which underlies AMI, and links this to the generation of helplessness and cardiopathic processes.