Blunted hormone responses to Ipsapirone are associated with trait impulsivity in personality disorder patients.

Impulsive aggression is associated with central serotonergic dysfunction. Animal models particularly implicate the 5-HT(1A) receptor in this behavior. We tested the hypothesis that central 5-HT(1A) receptor function is impaired in impulsive aggressive personality disorder patients. A total of 52 individuals with DSM-III-R personality disorders, all medically healthy adult outpatients without concurrent psychiatric medication treatment, underwent serial plasma cortisol, prolactin, and temperature measurements before and after ipsapirone 20 mg oral administration. Subjects completed self-report measures of impulsivity, hostility, depression and anxiety, and childhood maltreatment. Stepwise regression analysis revealed impulsivity alone among symptom measures to be associated with significantly decreased peak cortisol and prolactin responses. Diagnoses of borderline personality disorder (BPD) and intermittent explosive disorder-revised (IED-R) were associated with significantly increased and decreased cortisol responses, respectively. However, post hoc analyses indicated that impulsivity was significantly negatively correlated with cortisol responses in the BPD group, and may mediate the association of both BPD and IED-R with altered cortisol responses. Temperature response was associated with neither diagnostic nor symptom measures. Neither diagnostic nor dimensional measures of depression or anxiety, nor severity of childhood maltreatment, were significantly associated with cortisol, prolactin, or temperature responses. Impulsivity is related to impaired function at (or downstream to) postsynaptic 5-HT(1A) receptors, and this relationship may be partly responsible for the association of impaired serotonergic function with diagnoses such as BPD and IED-R. In addition, D(2) receptor dysfunction may play a role in impulsivity, whereas 5-HT(1A) cell-body autoreceptor function may be spared in these disorders.

Risperidone in the treatment of schizotypal personality disorder.

OBJECTIVE: Schizotypal personality disorder (SPD) has many phenomenological, genetic, physiologic, and neuroanatomical commonalities with schizophrenia. Patients with the disorder often suffer from marked social and occupational impairment, yet they have been difficult to treat with medications because of their unusual sensitivity to side effects. This study was designed to determine whether low-dose risperidone treatment is acceptable to SPD patients and can reduce characteristic schizotypal symptoms. In addition, if SPD patients respond to an antipsychotic medication, this will provide support for the notion of a commonality in treatment response between SPD and schizophrenia. METHOD: Twenty-five patients with DSM-IV-defined SPD were entered into a 9-week randomized, double-blind, placebo-controlled study of low-dose risperidone (starting dose of 0.25 mg/day, titrated upward to 2 mg/day) in the treatment of SPD. Patients were rated with the Positive and Negative Syndrome Scale (PANSS), the Schizotypal Personality Disorder Questionnaire, the Hamilton Rating Scale for Depression, and the Clinical Global Impressions scale. Data were collected from 1995 to 2001. RESULTS: The subjects had a low incidence of depression and of comorbid borderline personality disorder. Patients receiving active medication had significantly (p <.05) lower scores on the PANSS negative and general symptom scales by week 3 and on the PANSS positive symptom scale by week 7 compared with patients receiving placebo. Side effects were generally well tolerated, and there was no group difference in dropout rate for side effects. CONCLUSION: Low-dose risperidone appears to be effective in reducing symptom severity in SPD and is generally well tolerated.

Blunted prefrontal cortical 18fluorodeoxyglucose positron emission tomography response to meta-chlorophenylpiperazine in impulsive aggression.

BACKGROUND: Impulsive aggression is a prevalent problem and yet little is known about its neurobiology. Preclinical and human studies suggest that the orbital frontal cortex and anterior cingulate cortex play an inhibitory role in the regulation of aggression. METHODS: Using positron emission tomography, regional metabolic activity in response to a serotonergic stimulus, meta-chlorophenylpiperazine (m-CPP), was examined in 13 subjects with impulsive aggression and 13 normal controls. The anterior cingulate and medial orbitofrontal regions were hypothesized to respond differentially to m-CPP in patients and controls. In the frontal cortex, regional metabolic glucose response to m-CPP was entered into a group (impulsive aggressive, control) x slice (dorsal, middle, orbital) x position (medial, lateral) x location (anterior, posterior) x hemisphere (right, left) mixed-factorial analysis of variance design. A separate group (impulsive aggressive, controls) x anteroposterior location (Brodmann areas 25, 24, 31, 29) x hemisphere (right, left) analysis of variance was used to examine regional glucose metabolism in the cingulate gyrus. RESULTS: Unlike normal subjects, patients with impulsive aggression did not show activation specifically in the left anteromedial orbital cortex in response to m-CPP. The anterior cingulate, normally activated by m-CPP, was deactivated in patients; in contrast, the posterior cingulate gyrus was activated in patients and deactivated in controls. CONCLUSIONS: The decreased activation of inhibitory regions in patients with impulsive aggression in response to a serotonergic stimulus may contribute to their difficulty in modulating aggressive impulses.