Biomedical subjects

Larry Siever

Publications and source records attributed to Larry Siever.

3 recordsLinked to original sources

PubMed2005

Suicidal disorders: a nosological entity per se?

An extensive body of data has repeatedly shown in the past decades that suicidal behaviors are associated with several external validators such as low serotonergic activity in body fluids and in brains of suicide victims, genetic transmission of suicide risk independently of transmission of associated major psychiatric disorders, and more recently association with several serotonin-related genes. Despite these concordant findings, suicidal behaviors are still not considered as a nosological entity per se in standardized classification. The aim of this study is to review the existing literature establishing the validity of this entity through clinical, genetic, biochemical, and therapeutic arguments all leading to the need to recognizing suicidal behavior as an independent and possibly dimensional clinical entity.

Brain↗

PubMed2004

Trauma, genes, and the neurobiology of personality disorders.

A model for personality dysfunction posits an interaction between inherited susceptibility and environmental factors such as childhood trauma. Core biological vulnerabilities in personality include dimensions of affective instability, impulsive aggression, and cognition/perceptual domains. For the dimension of impulsive aggression, often seen in borderline personality disorder (BPD), the underlying neurobiology involves deficits in central serotonin function and alterations in specific brain regions in the cingulate and the medial and orbital prefrontal cortex. The role of trauma in the development of personality disorder and especially for BPD remains unclear. Although recent studies suggest that BPD is not a trauma-spectrum disorder and that it is biologically distinct from posttraumatic stress disorder, high rates of childhood abuse and neglect do exist for individuals with personality dysfunction. Personality symptom clusters seem to be unrelated to specific abuses, but they may relate to more enduring aspects of interpersonal and family environments in childhood. Whereas twin and family studies indicate a partially heritable basis for impulsive aggression, studies of serotonin-related genes to date suggest only modest contributions to behavior. Gene-environment interactions involving childhood maltreatment are demonstrated in recent studies on antisocial behaviors and aggressive rhesus monkeys and highlight the need for further research in this important area.

Adult↗

PubMed2003

Dexamethasone suppression test findings in subjects with personality disorders: associations with posttraumatic stress disorder and major depression.

OBJECTIVE: Previous studies using the 1.0-mg dexamethasone suppression test (DST) in subjects with personality disorders have produced mixed results. However, these studies focused on major depression and did not consider the possible effects of the comorbidity of posttraumatic stress disorder (PTSD). PTSD has been shown to be associated with increased cortisol suppression. To investigate the effect of PTSD, the authors conducted a 0.5-mg DST, which is more sensitive than the 1.0-mg DST for detection of increased cortisol suppression, in a group of subjects with personality disorders. METHOD: Subjects with personality disorders (N=52) ingested 0.5 mg of dexamethasone. Pre- and postfasting blood samples were drawn for measurement of cortisol levels. A three-way analysis of covariance was used to test for the main effects of major depression, PTSD, and gender on percent cortisol suppression, with plasma dexamethasone concentration as a covariate. Secondary analyses assessed for main and interaction effects of age at which trauma(s) occurred and a diagnosis of borderline personality disorder. RESULTS: Neither major depression nor gender had a significant effect on percent cortisol suppression. Subjects with PTSD had significantly higher percent cortisol suppression than subjects with major depression. Age at which trauma(s) occurred and a borderline personality disorder diagnosis had no significant main or interaction effects on cortisol suppression. CONCLUSIONS: A high level of cortisol suppression was associated with PTSD in subjects with personality disorder. This finding is similar to published findings for PTSD subjects without personality disorders. Major depression, gender, age when trauma(s) occurred, and a diagnosis of borderline personality disorder did not have significant main or interaction effects on cortisol suppression.

Adult↗