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Biomedical subjects

P Cosyns

Publications and source records attributed to P Cosyns.

At least 91 records · Page 5Linked to original sources
PubMed1990

Clinical subtypes of unipolar depression: Part II. Quantitative and qualitative clinical differences between the vital and nonvital depression groups.

This study examines whether the differences in the cluster-analytically generated classes--nonvital versus vital depression--are dimensional (quantitative) rather than categorical (qualitative). To this end, we used various pattern-recognition methods based on principal component analysis (PCA), e.g., display methods (PC plotting), eigenanalysis, and SIMCA (statistical isolinear multiple components analyses). We found several arguments supporting the dimensional hypothesis that the nonvital and vital classes constitute relevant stages (continuous categories) in the continuum of illness-severity. Nevertheless, we found some arguments supporting the categorical hypothesis that the cluster-analytically generated classes are qualitatively different with reference to the similarity of the vital symptoms. Our findings suggest that a nosological or categorical classification is possible from the moment that one component (i.e., the vital component) is quantitatively prominent to the extent that it has become qualitative. As the overall severity of illness increases, vital symptoms emerge which, grouped together, shape a new symptom profile (i.e., vital depression). Thus, our results favor the hypothesis that there are simultaneous quantitative (dimensional: overall severity of illness) and qualitative (categorical: vital symptoms) differences between the nonvital and vital depression groups.

Adult↗
PubMed1990

Clinical subtypes of unipolar depression: Part III. Quantitative differences in various biological markers between the cluster-analytically generated nonvital and vital depression classes.

The hypothalamic-pituitary-adrenal (HPA) axis, the hypothalamic-pituitary-thyroid (HPT) axis, and the availability of L-tryptophan (L-TRP) to the brain were studied in their relationships to (1) 14 depressive symptoms measured by the Structured Clinical Interview for DSM-III-R--Patient Version (SCID) and (2) the cluster-analytically generated vital/nonvital classes. The following biological parameters were measured in 100 depressed females: free thyroxine (FT4), baseline thyroid stimulating hormone (TSH), predexamethasone and postdexamethasone cortisol and adrenocorticotropic hormone (ACTH) values, the circulating levels of total L-TRP, and the L-TRP/sum of competing amino acids ratio. We found that the psychopathological correlates of disorders in the HPA/HPT axis and of a decreased availability of L-TRP were vital symptoms, i.e., distinct quality of mood, nonreactivity, early morning awakening, anorexia-weight loss, and psychomotor disorders. There was no significant relationship between those biological markers and the nonvital symptoms of the SCID inventory for depressive symptoms. However, we did not validate our SCID clustering in vital and nonvital classes by qualitative differences in the biological variables. It was concluded that our nonvital/vital clusters should be regarded as continuous categories with regard to the biological markers studied; these clusters constitute relevant stages in the continuum of progressing biological dysfunction.

Adrenocorticotropic Hormone↗
PubMed1990

A double-blind comparative study of remoxipride and haloperidol in schizophrenic and schizophreniform disorders.

The antipsychotic effect of remoxipride was compared to that of haloperidol in a randomized double-blind study with parallel group design comprising 98 patients with schizophrenia or schizophreniform disorder according to DSM-III. After a 3-7 day placebo washout period, patients received either 150-600 mg of remoxipride or 5-20 mg of haloperidol daily for 6 weeks. No significant differences in efficacy were found between the two treatments. Treatment-emergent checklist symptoms such as hypokinesia, rigidity, and tremor occurred more frequently and were more severe during haloperidol than during remoxipride treatment despite a significantly higher concurrent use of anticholinergic drugs in the haloperidol group. Haloperidol-treated patients reported greater increases in sleep and salivation than remoxipride-treated patients. Shoulder shaking and tremor were reported as occurring more frequently in the haloperidol group according to the Simpson and Angus rating scale for extrapyramidal symptoms. In summary, the two drugs seemed to be equally efficacious, though the tolerability profile favoured remoxipride.

Adult↗
PubMed1989

Hypothalamic-pituitary-adrenal and -thyroid axis dysfunctions and decrements in the availability of L-tryptophan as biological markers of suicidal ideation in major depressed females.

Several neurochemical correlates of suicide were recently detected. Some authors found increased disorders in the hypothalamic-pituitary-adrenal (HPA) and -thyroid (HPT) axes and disturbances in serotonergic neurotransmission in suicidal patients. In order to investigate the biological correlates of suicidal ideation, we measured the following: basal thyrotropin-secreting hormone (TSH), free thyroxine (FT4), pre- and postdexamethasone cortisol, adrenocorticotropic hormone (ACTH) levels, the circulating concentrations of total L-tryptophan (L-TRP) and the ratio between L-TRP and competing amino acids (CAA). The subjects were 17 suicidal and 17 nonsuicidal major depressed females matched for age and severity of illness. We found no significant differences in any of the above-mentioned biological data between patients with suicidal ideation and those without.

Adrenocorticotropic Hormone↗
PubMed1989

Explorative single-blind study on the sedative and hypnotic effects of buspirone in anxiety patients.

In this single-blind study the sedative and hypnotic properties of buspirone, a nonbenzodiazepine anxiolytic, were investigated in 8 anxious outpatients. Polysomnographic recordings were gathered during baseline, at the start of active medication, after 3 weeks of treatment and one night after discontinuing treatment. Daytime alertness was measured using the Multiple Sleep Latency Test and performance tests. The effects of buspirone on sleep structure were minimal and of no clinical consequence. Subjectively, the patients reported improved sleep quality. There were no effects on daytime alertness at the beginning, after 3 weeks or at sudden discontinuation of the medication. It is concluded that buspirone does not have a sedative or hypnotic effect in anxiety patients.

Adult↗
PubMed1989

Results of the 8 a.m. dexamethasone suppression test constitute a suitable tool for confirming the diagnosis of melancholia. A test unaffected by the variations in the bioavailability of dexamethasone.

This prospective study was conducted in order (1) to examine which postdexamethasone cortisol value i.e., 8 a.m., 4 p.m. or peak cortisol - is most suitable as a laboratory test to help confirm the diagnosis of melancholia and (2) to investigate the influence of the dexamethasone levels in the results of the dexamethasone suppression test (DST). To this end we administered the DST to 48 controls and 115 depressed inpatients categorized according to DSM-III. The 8 a.m. and 4 p.m. dexamethasone levels were determined in 100 subjects. We found that an 8 a.m. postdexamethasone cortisol value greater than or equal to 3.5 micrograms/dl was of the most significant diagnostic value in order to separate melancholia from normal controls and/or minor depressives. The 8 a.m. and 4 p.m. dexamethasone values did not differ between healthy controls, minor and severely depressed patients. Although cortisol nonsuppressors exhibited significantly lower dexamethasone values, the predictive value of the DST for melancholia was not affected by the large variation in the bioavailability of dexamethasone.

Adult↗
PubMed1988

Psychosurgery and personality disorders.

Defining personality and its pathological variants is a hazardous enterprise. The personality concept refers to the global coherence of functioning of a person as a whole and can be divided into two components, temperament and character. Personality disorders will be discussed according to the DSM III-R (1987) (The Diagnostic and Statistical Manual of Mental Disorders) the most recent psychiatric taxonomy of the American Psychiatric Association. The interaction between psychosurgery and personality is multiple. It will be stated that the mere presence of a personality disorder in a patient should never be an indication for psychosurgery. It may sometimes even act as a contraindication. Psychosurgery can produce changes in some basic psychic dysfunctions and although there is no universally accepted understanding of how it works, some hypothetical neurobiological foundations will be discussed.

Humans↗
PubMed1980

Electrical stimulation of the central gray for pain relief in human: autopsy data.

Anatomopathological studies are reported of 5 brains in which electrical stimulation of the periventricular--periaqueductal gray was applied for the treatment of chronic pain. It was found that the recommended target was reached in 4 cases (only 1 case out of 5 was successful as far as a pain relief is concerned). PtIr electrodes caused little tissue reaction. The chronic stimulation had not provoked lesions observable by light-microscopy.

Brain↗
PubMedDate not supplied

Pituitary and adrenal hormone responsiveness to Synacthen in melancholic subjects versus subjects with minor depression.

Increased adrenal cortex responsiveness to adrenocorticotropic hormone (ACTH) has been suggested to contribute to increased cortisol secretion in dexamethasone nonsuppression and melancholia. To further examine this hypothesis, the following variables were examined in 68 patients with unipolar depression (minor, n = 24; simple major, n = 25; melancholic, n = 19): basal or post-Synacthen [ACTH(1-24), 250 micrograms IV] intact ACTH(1-39), beta-endorphin/beta-lipotropin, cortisol, and androstenedione concentrations, as well as the postdexamethasone (DST) plasma ACTH(1-39) and cortisol values. Melancholic subjects showed significantly higher baseline ACTH(1-39), beta-endorphin/beta-lipotropin, and androstenedione values compared with subjects with minor depression. No significant differences in post-Synacthen cortisol or androstenedione secretion between any of the groups or between [ACTH(1-39) or cortisol] DST nonsuppressors and suppressors were found. No significant relationships between DST and ACTH test results were observed. Abnormally increased post-DST cortisol values in melancholic subjects were highly predicted (> 68% of the variance) by post-DST intact ACTH levels. ACTH(1-39) values were significantly lower after Synacthen administration in melancholic subjects than in subjects with minor depression. These results are not consistent with the hypothesis that melancholia is characterized by an increased adrenocortical responsivity to exogenous ACTH compared with minor depression or that DST nonsuppression is due to adrenal hyperresponsiveness.

Adrenal Cortex Hormones↗
PubMedDate not supplied

Relationships between basal hypothalamic-pituitary-thyroid-axis activity and plasma haptoglobin levels in depression.

The present study was carried out in investigate the relationship between basal hypothalamic-pituitary-thyroid (HPT)-axis function and the acute phase (AP) response in depression. Toward this end, the authors measured serum concentrations of basal thyroid-stimulating-hormone (TSH), free thyroxine (FT4) and free triiodothyronine (FT3), and plasma levels of an AP protein, i.e. haptoglobin (Hp) in 38 depressed in-patients and in 11 normal controls. In depression, basal TSH was significantly and negatively related to Hp values, whereas in normal controls a trend toward a positive correlation between both factors was found. Depressed patients with increased Hp levels (> or = 250 mg/dl) showed significantly lower basal TSH levels than patients with normal Hp levels. No significant correlations were found between Hp plasma levels and either FT4 or FT3 serum concentrations. The results support the hypothesis that lower TSH secretion in major depression may be related to the AP response in that illness, and may constitute an expression of a coordinated neuroendocrine-immune response to nonthyroidal illness.

Acute-Phase Reaction↗
PubMedDate not supplied

Impaired mitogen-induced lymphocyte responses and the hypothalamic-pituitary-adrenal axis in depressive disorders.

The lymphocyte stimulation responses to the mitogens phytohemagglutinin (PHA), concanavalin A (Con A) and pokeweed (PWM) were investigated in 30 hospitalized depressed women undergoing a dexamethasone suppression test (DST). Patients were classified according to DSM-III as having major depression with melancholia, without melancholia, and minor depression. The Hamilton Depression Rating Scale (HDRS) and the State-Trait Anxiety Inventory (STAI) were measured. Patients with major depression showed significantly decreased lymphocyte stimulation induced by PHA, Con A, and PWM as compared to those with minor depression. These differences could not be attributed to age, body weight, weight loss, total number of leukocytes, menopausal status, sleep disturbances, concomitant use of low-dosage benzodiazepines or length of drug-free period before testing. The group mean differences in lymphocyte stimulation counts were not affected by the severity of illness or the severity of state and trait anxiety. There were no significant differences in the lymphocyte responses to PHA, Con A, and PWM between DST non-suppressors and DST suppressors. No significant correlations were established between baseline and post dexamethasone cortisol values and the lymphocyte stimulation counts.

Adult↗
PubMedDate not supplied

A revised interpretation of the TRH test results in female depressed patients. Part I: TSH responses. Effects of severity of illness, thyroid hormones, monoamines, age, sex hormonal, corticosteroid and nutritional state.

Thyrotropin secreting hormone (TSH) levels were recorded in baseline conditions and 20 and 60 min after thyrotropin releasing hormone (TRH) administration (200 micrograms i.v.) in 60 depressed females categorized according to DSM-III. Basal TSH (TSHB) and peak TSH responses (TSHP) were measured using ultrasensitive RIA assays. The use of delta max TSH (TSHP minus TSHB) had no advantage over the use of TSHP since both factors were almost linearly (r = 0.98) correlated. TSHP was largely (72% of the variance) predicted by TSHB. It was suggested that TSHP consisted of two components. The first part was a relative deduction from TSHB. The second part was the newly proposed concept of the residual TSH (TRHR). This part was computed by partialling out the relative effects of TSHB on TSHP by means of regression analysis. In clinical practice two relevant factors should be used to evaluate the hypothalamic-pituitary-thyroid (HPT) axis: (1) TSHB reflecting the setpoint of the HPT axis and (2) TSHR reflecting the latent capacity of the HPT axis to respond to overwhelming amounts of exogenous TRH. TSHB was significantly reduced in severely depressed patients (296.X3, 296.X4) as compared with minor depressives (300.40, 309.00). These differences could be attributed to significantly increased free thyroxine levels and to noradrenergic hyperactivity in the severely depressed females. TSHR correlated significantly and negatively with follicle stimulating hormone levels, age, body mass index and the post-dexamethasone cortisol values. TSHR was significantly reduced in the post-menopausal state.

Adult↗
PubMedDate not supplied

A revised interpretation of the TRH test results in female depressed patients. Part II: Prolactin responses. Relationships with sex hormones, corticosteroid state, age, monoamines and amino acid levels.

Prolactin (PRL) levels were recorded in baseline conditions and 20 and 60 min after thyrotropin releasing hormone (TRH) administration (200 micrograms i.v.) in 60 depressed females categorized according to DSM-III. Peak PRL responses were significantly (r = 0.727, P less than 0.001) correlated with their baseline levels. Consequently, the PRL responses to TRH were largely predicted by baseline PRL levels. It was suggested that the PRL responses to TRH consisted of two parts. The first component was a relative exaggeration of basal PRL, reflecting the basal activity of the hormone. The second component was the residual response. This part was estimated by partialling out the relative effects of basal PRL on peak PRL responses by means of regression analysis. Basal PRL and residual PRL responses were uninformative for major depression. Post-menopausal females showed significantly reduced basal PRL levels. There was a significant negative correlation between basal PRL and follicle stimulating hormone levels, age and post-dexamethasone cortisol values. The residual PRL responses were negatively correlated with free triiodothyronine levels and positively with serotonergic variables, i.e., 5-hydroxyindoleacetic acid in 24-h urine and the ratio L-tryptophan/competing amino acids.

Adult↗