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Biomedical subjects

H M van Praag

Publications and source records attributed to H M van Praag.

At least 91 records · Page 5Linked to original sources
PubMed1989

Is there a relation between the seriousness of suicidal intent and the lethality of the suicide attempt?

The relation between the strength of an individual's intent to commit suicide and the nature and seriousness (lethality) of any suicide attempt has been a controversial one. Some studies suggest a positive correlation, while others report no connection. The present investigation included 60 patients, who were studied shortly after they had been admitted to a medical service after a suicide attempt. Measures of depression, impulsivity, suicidal intent, seriousness of the attempt, and efforts to prevent intervention were obtained. Results reveal that both depression and impulsivity correlate positively with the strength of the intent to commit suicide, but there appears to be almost no correlation in this population between measures of intent and seriousness of the attempt.

Adolescent↗
PubMed1989

Correlates of suicide and violence risk: III. A two-stage model of countervailing forces.

Questionnaires and self-report scales were administered to 100 psychiatric inpatients. The scales measured such variables as depression, hopelessness, impulsivity, mental and life problems, family violence, personality characteristics, and dyscontrol tendencies. These were correlated with indices of suicide risk and violence risk. Most variables were found to correlate significantly with both suicide and violence risk. Partial correlation analyses revealed that 10 variables correlated significantly with suicide risk but not violence risk, while four variables correlated significantly with violence risk but not suicide risk. A two-stage model of countervailing forces, incorporating concepts from both psychoanalysis and ethology, is presented as a way of interpreting the results.

Adult↗
PubMed1989

Moving ahead yet falling behind. A critical appraisal of some trends in contemporary depression research.

The progress of psychiatry over the past few years is impressive. That process, however, is nonlinear and in this paper three developments in depression research are discussed and thought to be counterproductive. First, the depression classification as institutionalized by the DSM-III is an unfocused and confusing one. The regular revisions, moreover, largely based on the opinions of experts rather than on the research by experts, add to the confusion. Second, the preoccupation of biological psychiatry with nosology is seen as a growth-inhibiting factor. The functional/dimensional approach searching for correlations between biological and psychological dysfunctions, an approach we have been advocating for many years, seems to have great potential and deserves to be included in mainstream biological psychiatry. Finally, the 'biologization' of depression research went too far. The conception of depression as a brain disease is a 'terrible simplification', even for the syndrome considered to be the most 'biological' of all: major depression, melancholic type. Psychological determinants of the brain dysfunctions underlying depressive disorders deserve as much scientific scrutiny as their biological counterparts. The mind should not be the soft belly of (biological) psychiatry.

Arousal↗
PubMed1989

Diagnosing depression--looking backward into the future.

Before the advent of antidepressants, no generally accepted and operationalized classification of depression existed. In the late fifties and sixties we developed a multi-axial and operationalized depression taxonomy in order to be able to study systematically the clinical and biochemical action of antidepressants and biological characteristics of depressives responsive to antidepressants. The keypoints of that system and the data on which it was based are discussed, after which it is compared with the depression classification proposed by the DSM III and DSM III-R. Though it is recognized that a system based on consensus opinion can never be overall acceptable to everyone, the conclusion is reached that the DSM depression classification is outright unsatisfactory and contributes to diagnostic confusion rather than to reduce it. It is recommended that an immediate moratorium should be laid on expert-opinion-based alterations in the classification of depressions and that future changes will be based only on research specifically designed to resolve issues pertinent to that classification. In organizing, conducting and funding such a collaborative, goal-directed effort, the National Institute of Mental Health could play a seminal role.

Adjustment Disorders↗
PubMed1988

Neuroendocrine evidence for serotonin receptor hypersensitivity in panic disorder.

Normal controls (NC) (n = 15), patients with panic disorder (PD) (n = 13) and patients with major depression (MD) (n = 17) were challenged with a single, oral dose (0.25 mg/kg) of the selective 5HT agonist m-chlorophenyl-piperazine (MCPP) or placebo. Blood samples were assayed for cortisol and MCPP levels every 30 min. The PD group had an augmented cortisol release when compared to the other two groups. Finally, a significant correlation was found across all subjects between clinical anxiety level and cortisol release on MCPP. These data support the hypothesis of 5HT receptor hypersensitivity in PD.

Adult↗
PubMed1988

High-dose naloxone in tardive dyskinesia.

Tardive dyskinesia (TD) is thought to result from nigrostriatal dopaminergic supersensitivity secondary to prolonged neuroleptic exposure. Preclinical studies have demonstrated that the opiate antagonist naloxone can acutely reverse a haloperidol-induced hyperdopaminergic state. In a trial of high-dose naloxone, 20 patients with TD received i.v. naloxone (20 mg, 40 mg, and placebo) under double-blind conditions. At baseline and at regular postdrug intervals, patients were evaluated using a battery of motor, clinical, and neuropsychological measures to study effects on neurological, behavioral, and cognitive functions. There was a significant improvement in involuntary movements at 30 min postnaloxone, together with improvement in clinical ratings at that time point, as well as some cognitive changes. The implications of these findings for the putative functional relationship between dopaminergic and enkephalinergic systems in the nigrostriatal area are discussed.

Adult↗
PubMed1988

Increased suicidality in depression: group or subgroup characteristic?

A lifetime history of depressive episodes and suicide attempts was ascertained from 172 depressed patients admitted to a psychiatric inpatient service. Fifty-five of these patients had made at least one suicide attempt. The correlation of depressive episodes and the total number of suicide attempts for this group was close to zero. However, when the data were converted into rate measures (number of episodes or attempts per year), the correlations were very high and significant. It appears that approximately one-third of severely depressed, hospitalized patients have a history of suicide attempts and, once a suicide attempt has occurred, the patient is at high risk for more suicide attempts if future depressions occur. Within the group of depressives with a history of suicide attempt, the risk of suicidal behavior is evenly distributed. No evidence in favor of a "hypervulnerable" subgroup was found.

Adolescent↗
PubMed1988

Behavioral indications for serotonin receptor hypersensitivity in panic disorder.

Immediate placebo-corrected behavioral responses to m-chlorophenylpiperazine (MCPP), a selective serotonin agonist, are reported in 11 normal controls, 10 patients with panic disorder, and 10 patients with major depression. Whereas the normal and depressed groups showed no noteworthy behavioral response, panic disorder patients became more anxious, depressed, and hostile, and 60% had panic attacks. These data suggest a hypersensitive postsynaptic serotonin receptor system in some panic disorder patients.

Adult↗
PubMed1988

The role of serotonin in schizophrenia.

Studies examining serotonin (5-hydroxytryptamine; 5HT) in schizophrenia show variable and inconsistent findings, which might reflect the heterogeneity of the disease. When these studies are reviewed in the light of Crow's "two-syndrome" paradigm of schizophrenia, a new trend emerges. It appears that 5HT findings may be related to certain features of Type II schizophrenia such as negative symptoms, degenerative brain changes, and chronicity in the following manner: (1) 5HT2 antagonists, which have recently become available, have been shown to have an antipsychotic effect, particularly on the negative symptom cluster. (2) Decreased levels of 5-hydroxyindoleacetic acid in cerebrospinal fluid have been found to be correlated with cortical atrophy or ventricular enlargement in schizophrenic patients. (3) A subgroup of chronic schizophrenic patients has been shown to have elevated levels of platelet or whole blood 5HT. We propose, then, that 5HT dysfunction might be related to Type II, or negative syndrome, schizophrenia, and that the nature of this dysfunction might involve 5HT postsynaptic receptor hypersensitivity. We further suggest that the pharmacotherapy of schizophrenia should include a 5HT-blocking component, as well as a dopamine-blocking component, and we propose that future research should address the role of selective 5HT receptor hypersensitivity in schizophrenia.

Brain↗
PubMed1988

Effect of tyrosine on attention deficit disorder with hyperactivity.

A single-blind study was conducted to evaluate the effect of oral tyrosine on attention deficit disorder (ADD) with hyperactivity in seven outpatient children. Since most biological evidence of ADD supports a norepinephrine or dopamine deficiency, the authors hypothesized that tyrosine, which has been shown to increase catecholamine synthesis, would be beneficial in the treatment of ADD. None of the subjects, however, showed any significant improvement with tyrosine. Implications for the catecholamine deficiency hypothesis and treatment strategies for ADD are discussed.

Administration, Oral↗
PubMed1987

Hormonal probes of central serotonergic activity: do they really exist?

The response of a hormone allegedly under 5-hydroxytryptaminergic (5-HT-ergic) control to a compound stimulating or inhibiting serotonergic activity has been used as a measure of the functional state of central serotonergic systems. The relevant literature is reviewed, and based on that, it is concluded that, as yet, no reliable hormonal 5-HT probe exists. The main problems are nonselectivity of the challengers and noncomparability of individual studies because of variations in dose and route of administration. An acceptable hormonal 5-HT probe should at least have passed the following three tests. The influence of the challenger on catecholaminergic (CA) systems must be rendered unlikely in humans to avoid the pitfalls of, say, the 5-HT precursors whose CA-ergic influences have been overlooked. Dose-response relationships must be established to avoid the confusion caused by different investigators using the challenger in different doses. It must be demonstrated that the effect of the challenger is counteracted by its functional opponent.

Central Nervous System↗