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Biomedical subjects

T B Horvath

Publications and source records attributed to T B Horvath.

At least 19 recordsLinked to original sources
PubMed1995

Lateral ventricular enlargement in schizotypal personality disorder.

Although an increase in the ratio of ventricular space to brain (ventricle-brain ratio), VBR) on computed tomography (CT) has been among the most robust findings in chronic schizophrenia, VBR has not been investigated in a large, well-characterized clinical population of patients with schizotypal personality disorder (SPD), a clinical entity with a phenomenologic, gentle biological, and treatment response relationship to chronic schizophrenia. Accordingly, CT scans were obtained in 36 male SPD patients, 23 males with other personality disorders, 133 male schizophrenic patients, and 42 male normal volunteers. The mean body of the lateral VBR was significantly greater in the SPD patients than in the patients with other personality disorders. The VBR of the SPD patients did not differ significantly from either that of the normal volunteers or the schizophrenic patients but was intermediate between the two groups. There were no correlations with either psychotic-like or deficit-related symptoms of SPD in either the SPD or total personality disorder cohorts. SPD patients, like schizophrenic patients, may have increased VBRs compared wit patients with other personality disorders; their VBRs fall between the means of schizophrenic patients and normal control subjects.

Adult↗
PubMed1994

Familial correlates of reduced central serotonergic system function in patients with personality disorders.

BACKGROUND: To test the hypothesis that evidence of reduced central serotonergic (5-HT) system function in probands with personality disorders is associated with an elevated morbid risk of psychopathological conditions putatively associated with 5-HT dysfunction in first-degree relatives of these probands. METHODS: Data were collected during a study of the 5-HT correlates of behavior in male patients with DSM-III personality disorders conducted at a Veterans Affairs medical center. Probands in this study were selected from those patients who had undergone both a fenfluramine hydrochloride challenge and a family history assessment. Axis II diagnosis were made according to DSM-III criteria after a structured interview of the proband, using the Structured Interview for Diagnosing Personality Disorders, given by two raters and a similar interview with a knowledgeable informant by another rater. RESULTS: Reduced prolactin responses to the 5-HT releasing/uptake inhibiting agent fenfluramine was associated with an elevated morbid risk of impulsive personality disorder traits in the first-degree relatives of patients with a primary DSM-III diagnosis of a personality disorder. Quantitative scores on assessments of impulsive aggression in the probands were not correlated with an increased morbid risk for impulsive personality disorder traits. A trend in the same direction was noted for affective personality disorder traits and alcoholism. CONCLUSIONS: These results suggest that a central 5-HT system abnormality in probands is associated with an increased risk of impulsive aggression in their first-degree relatives, and that assessment of central 5-HT system function in probands may be a more sensitive parameter for identification of this familial trait than the presence of impulsive aggressive behaviors in the proband.

Aggression↗
PubMed1993

CSF homovanillic acid in schizotypal personality disorder.

CSF concentrations of homovanillic acid (HVA) were measured in 10 patients with schizotypal personality disorder and 14 patients with other personality disorders. The patients with schizotypal personality disorder had higher CSF HVA concentrations than the patients with other personality disorders. Furthermore, the psychotic-like schizotypal symptoms correlated positively with the CSF HVA concentrations. These results suggest a central dopaminergic dysfunction associated with the psychotic-like symptoms of schizotypal personality disorder.

Adult↗
PubMed1993

Schizophrenia-related and affective personality disorder traits in relatives of probands with schizophrenia and personality disorders.

OBJECTIVE: The possible heterogeneity of the schizophrenia-related personality disorder traits associated with DSM-III criteria for schizotypal personality disorder was investigated using the family history method. A familial relationship to schizophrenia was hypothesized for schizophrenia-related personality disorder traits without coexisting affective personality disorder traits, pure schizophrenia-related personality disorder traits. Alternatively, a familial relationship with borderline personality disorder was hypothesized for schizophrenia-related personality disorder traits with comorbid affective personality disorder traits. METHOD: Criteria for schizophrenia-related and affective personality disorder traits were used to assess the 588 nonpsychotic first-degree relatives of 55 chronic schizophrenic probands and 67 probands with personality disorders. The probands with one or more DSM-III personality disorders were categorized as having schizotypal personality disorder without borderline personality disorder (pure schizotypal personality disorder), borderline personality disorder without schizotypal personality disorder (pure borderline personality disorder), both disorders, or neither. RESULTS: The morbid risk of all cases of schizophrenia-related personality disorder traits was higher in relatives of probands with schizophrenia and pure schizotypal personality disorder than in relatives of probands with neither schizotypal nor borderline personality disorder; however, it differed only slightly from that observed in the relatives of probands with both schizotypal and borderline personality disorders and pure borderline personality disorder. In contrast, the risk of pure schizophrenia-related personality disorder traits was higher in relatives of probands with schizophrenia and pure schizotypal personality disorder, while the risk of coexisting schizophrenia-related and affective personality disorder traits was lower in both of these groups than among the relatives of probands with both schizotypal and borderline personality disorders and pure borderline personality disorder. CONCLUSIONS: These results offer preliminary indications that schizotypal personality disorder features present without comorbid affective personality disorder traits may more specifically characterize the personality characteristics familially related to schizophrenia. Furthermore, they indicate that schizotypal personality disorder features as currently defined are found in relatives of patients other than those with schizophrenia or schizotypal personality disorder.

Adult↗
PubMed1992

The growth hormone response to clonidine in acute and remitted depressed male patients.

The growth hormone (GH) response to clonidine was evaluated in 28 acutely depressed male patients, 17 remitted depressed patients, and 26 normal control subjects. The GH response to clonidine was blunted (delta less than 4 ng/ml) in a significantly increased proportion of both acute and remitted patients compared to control subjects. Covarying for age effects, the GH response to clonidine (as area-under-the-curve) was not significantly different between any of the three groups, but was significantly diminished in both the acute and remitted depressed patients who were ever hospitalized for an episode of depression, compared to control subjects. Six patients studied in both the acute and remitted states were blunted in both states. These findings could not be accounted for by other clinical and demographic variables including weight, time off antidepressants, severity of current depressive symptoms, and subtype of depression. These results raise the possibility that the blunted GH response to clonidine may represent a state-independent correlate of some forms of severe depression. Issues regarding the specificity and interpretation of this finding require further clarification.

Acute Disease↗
PubMed1991

Levels of opioid physical dependence in heroin addicts.

The levels of opioid physical dependence in a group of long-term heroin addicts were ascertained by measuring the severity of the opioid withdrawal syndrome before and after pharmacological challenge with either 0.4 mg naloxone or placebo. Prior to challenge, patients manifested some subjective symptoms but few objective signs of opioid withdrawal. Patients who received placebo (n = 18) showed a significant increase in the mean score on one of three rating scales used to assess opioid withdrawal. Patients who received naloxone (n = 58) showed significant increases in mean scores on all three rating scales, but this was due primarily to increases observed in a minority of patients. Sixty-one percent of patients failed to manifest clinically significant changes in subjective symptoms, and 74% of patients failed to manifest clinically significant changes in objective signs of opioid withdrawal following naloxone administration. The results suggest that a substantial subgroup of heroin addicts are able to use opioids regularly while maintaining relatively low levels of physical dependence.

Adult↗
PubMed1991

Cholinergic strategies in the treatment of Alzheimer's disease.

Since the identification of the cholinergic deficit, strategies aimed at enhancing cholinergic neurotransmission have dominated the field of pharmacology in Alzheimer's disease (AD). These strategies include increasing acetylcholine precursor availability, delaying synaptic degradation and stimulating muscarinic receptors. Although most clinical trials report mild symptomatic improvements in some patients, support for large-scale clinical use of cholinomimetics in AD is not yet available. This article presents the most representative clinical trials, discusses the limitations of the cholinergic strategies and suggests future directions in the treatment of AD.

Acetylcholine↗
PubMed1991

Affective and impulsive personality disorder traits in the relatives of patients with borderline personality disorder.

OBJECTIVE: This study tested the hypothesis that the risk for affective and impulsive personality disorder traits commonly found in patients with borderline personality disorder would be greater in the first-degree relatives of probands with borderline personality disorder than in two comparison groups. METHOD: Blind family history interviews were conducted with family informants to assess the extent to which first-degree relatives of 29 probands with borderline personality disorder, 22 probands with other personality disorders who met three or fewer of the criteria for borderline personality disorder, and 43 probands with schizophrenia fulfilled operationalized criteria for the two kinds of personality disorder traits and for other diagnostic categories. The crude proportions of adult relatives with each diagnosis, as well as the age-adjusted morbid risks, were assessed in the three groups of relatives. RESULTS: The risks for affective and impulsive personality disorder traits were independently greater in the 129 relatives of the borderline probands than in the 105 relatives of the probands with other personality disorders and the 218 relatives of the schizophrenic probands. There was no similarly greater risk for any other psychiatric disorder assessed, including major affective disorder. In addition, the relatives of borderline probands with current or past major depressive disorder showed a greater risk for major affective disorders than the relatives of never-depressed probands with other personality disorders but not the relatives of never-depressed borderline probands. CONCLUSIONS: These results suggest familial transmission of the hallmark borderline-related personality characteristics and raise the possibility that these familial traits may be partially independent.

Adult↗
PubMed1991

Plasma homovanillic acid in schizotypal personality disorder.

Schizotypal patients were found to have a significantly higher mean plasma HVA concentration than normal comparison subjects. Furthermore, plasma HVA concentration positively correlated with "psychotic-like" schizotypal symptoms. These results implicate dopaminergic mechanisms modulating the psychotic-like symptoms of schizotypal personality disorder.

Dopamine↗
PubMed1991

Neuroleptics improve sustained attention in schizophrenia. A study using signal detection theory.

To test the hypothesis that antipsychotic drugs improve attentional processes in schizophrenia, we used a computer-controlled, perceptually degraded continuous performance test (CPT), based on signal detection theory. CPT stimuli were degraded (blurred) to reduce discriminability so that signal detection analysis could be used to distinguish specific attentional processes, as measured by A', from nonspecific factors, as measured by B". Thirteen medicated and 12 neuroleptic-withdrawn schizophrenics visually monitored digits to detect a target under perceptually undegraded and degraded conditions. The principal result was that the neuroleptic-withdrawn patients showed a significant decline in the attention-specific measure of A' over time on task only for the degraded targets, independent of changes in the nonspecific index of B". These results demonstrate that neuroleptic withdrawal may compromise specific attentional processes, namely the ability to sustain attention, as measured by a precise performance task which controlled for nonspecific factors.

Adult↗
PubMed1990

Increased morbid risk for schizophrenia-related disorders in relatives of schizotypal personality disordered patients.

To evaluate whether probands from a clinical sample diagnosed as having DSM-III schizotypal and/or paranoid personality disorder have a familial relationship to the schizophrenia-related disorders, the morbid risk for schizophrenia-related disorders and other psychiatric disorders were evaluated in the first-degree relatives of patients with schizotypal and/or paranoid personality disorder and compared with the corresponding risk for these disorders in the first-degree relatives of patients with other non-schizophrenia-related personality disorders. The morbid risk for all schizophrenia-related disorders, and specifically for schizophrenia-related personality disorders, was significantly greater among the relatives of the probands with schizotypal and/or paranoid personality disorder than among the relatives of probands with other personality disorder. The morbid risk for other psychiatric disorders did not differ significantly between the first-degree relatives of the schizotypal/paranoid personality disorder and the other personality disorder control proband samples. These results suggest a specific familial association between schizophrenia-related disorders, particularly schizophrenia-related personality disorders, and clinically diagnosed schizotypal patients.

Adolescent↗
PubMed1989

Premorbid sociosexual functioning and long-term outcome in schizophrenia.

Chronic schizophrenic patients with the most severe social deterioration have been shown to differ from other chronic schizophrenic patients with respect to measures of left-to-right ventricular asymmetry, negative symptoms, and response to haloperidol treatment. In the current study, the authors investigated the social antecedents of these characteristics of very poor outcome schizophrenia in 69 chronic schizophrenic patients. Poor premorbid sociosexual functioning was associated with more severe left-to-right ventricular asymmetry, greater severity of negative symptoms, fewer positive symptoms, and worse current social functioning. These data suggest that factors associated with severe social deterioration in the end stage of schizophrenia are also associated with premorbid sociosexual impairment.

Adult↗
PubMed1988

4-Aminopyridine in the treatment of Alzheimer's disease.

The cognitive and behavioral effect of 4-aminopyridine (4-AP) was examined in Alzheimer's disease (AD) using a dose finding/replication study design. Fourteen inpatients, aged 54-89 years (mean 66.1 +/- 10.6 SD), meeting NINCDS criteria for probable AD, were studied. Three doses of 4-AP--2.5 mg b.i.d., 5 mg b.i.d., and 10 mg b.i.d.--or placebo were administered for 4 consecutive days in random order. Symptomatic assessment was performed on the fourth day of each condition using the Alzheimer Disease Assessment Scale (ADAS). Thereafter, the dose on which the best performance occurred was readministered, as was placebo. Of the 13 patients who completed the dose-finding phase, 7 patients had at least one dose of 4-AP that was associated with less severe symptoms than was placebo, and those patients were included in the replication phase. Results indicated no significant difference in total ADAS scores (p greater than 0.05). Examination of the ADAS subscales revealed no significant 4-AP effect on any particular symptom. Possible explanations of the lack of a drug effect in this study include the unselective release of neurotransmitters by 4-AP, poor penetration into the central nervous system (CNS), and the presenile onset of the disease in these patients.

4-Aminopyridine↗
PubMed1987

RS 86 in the treatment of Alzheimer's disease: cognitive and biological effects.

Twelve patients who met Research Diagnostic Criteria for Alzheimer's disease (AD) completed a double-blind crossover study comparing oral RS 86, a long-acting and specific muscarinic agonist, with placebo. Cognitive and noncognitive effects were assessed with the Alzheimer's Disease Assessment Scale (ADAS). RS 86 was found to improve ADAS test scores consistently (both cognitive and noncognitive subscales) in seven patients, with a clinically obvious improvement in only two patients. RS 86 produced a significant increase in peak nocturnal cortisol levels, and this increase correlated with improvement on ADAS testing. Similarly, there was a 38% increase in amplitude of the P300 evoked potential with RS 86. The biological findings suggest that RS 86 was effective only to the extent that it enhanced central cholinergic activity.

Aged↗