Hostility is associated with a low prolactin response to meta-chlorophenylpiperazine in abstinent alcoholics

Mistrustful and Misunderstood: A Review of Paranoid Personality Disorder

PURPOSE OF REVIEW

Paranoid Personality Disorder (PPD) has historically been neglected by science out of proportion to its prevalence or its association with negative clinical outcomes. This review provides an update on what is known about PPD regarding its prevalence, demographics, comorbidity, biological mechanism, risk factors, and relationship to psychotic disorders.

RECENT FINDINGS

PPD has long been the subject of a rich and prescient theoretical literature which has provided a surprisingly coherent account of the psychological mechanism of non-delusional paranoia. Available data indicate that PPD has a close relationship with childhood trauma and social stress. Descriptive data on a sample of 115 individuals with Paranoid Personality Disorder is examined in comparison with a group of individuals with Borderline Personality Disorder. The descriptive data largely confirm previously identified relationships between Paranoid Personality Disorder and childhood trauma, violence, and race. We identify important similarities to and differences from Borderline Personality Disorder.

SUMMARY

PPD continues to be an important construct in the clinic and the laboratory. Available data lead to a reconsideration of the disorder as more closely related to trauma than to schizophrenia.

Cortisol responses to ipsapirone challenge correlate with aggression, while basal cortisol levels correlate with impulsivity, in personality disorder and healthy volunteer subjects

BACKGROUND

This study was performed to test the hypothesis that 5-HT-1a receptors, as assessed by the cortisol (post-synaptic) and temperature (pre-synaptic) responses to the 5-HT-1a agonist, Ipsapirone (IPSAP), play a role in the regulation of impulsive aggressive behavior in human subjects.

METHODS

Fifty-two healthy subjects (28 with Personality Disorder: PD; 24 Healthy Volunteers: HV) underwent acute challenge with the selective 5-HT-1a agonist, ipsaprione (IPSAP: .3 mg/kg po). Residual Peak Delta Cortisol (ΔCORT[IPSAP]-R; after removal of Basal CORT and IPSAP plasma levels) was used as the primary 5-HT-1a post-synaptic receptor variable. Residual Nadir Delta Temperature (ΔTEMP[IPSAP]-R; after removal of Basal TEMP) was used as the primary 5-HT-1a somatodendritic (pre-synaptic) receptor variable. Measures of trait aggression included the Aggression scales of the Buss-Durkee Hostility Inventory (BDHI) and the Life History of Aggression (LHA); trait impulsivity was assessed with the Impulsivity scale of the Eysenck Personality Questionnaire (EPQ-II).

RESULTS

Correlations between ΔCORT[IPSAP]-R responses and BDHI Aggression scores varied by group. Specifically, BDHI Aggression correlated inversely with ΔCORT[IPSAP]-R values in PD subjects but directly in HV subjects. While EPQ-II Impulsivity did not correlate with ΔCORT[IPSAP]-R responses, this measure of impulsivity correlated directly with Basal CORT levels in all subjects. ΔTEMP[IPSAP]-R responses did not correlate with measures of trait aggression or trait impulsivity.

CONCLUSION

Physiologic responses of 5-HT-1a post-synaptic receptors may be reduced as a function of trait aggression, but not impulsivity, in PD subjects. In contrast, pre-synaptic 5-HT-1a receptors may not play a role in the regulation of aggression or impulsivity in human subjects.

Polymorphism in the serotonin transporter gene and moderators of prolactin response to meta-chlorophenylpiperazine in African-American cocaine abusers and controls

Serotonin (5-HT) function is altered in several psychiatric disorders, including cocaine dependence (CD), and its role in impulsive-aggressive behaviors has been widely studied. However, the relationship between psychopathological and behavioral dimensions and mechanisms of 5-HT alterations remains unclear. We investigated the relationship of a polymorphism in the 5' promoter region of the serotonin transporter gene (5-HTTLPR) with prolactin (PRL) response to meta-chlorophenylpiperazine (m-CPP) in a sample of 68 African-American individuals, 35 CD subjects and 33 controls. We also examined whether measures of impulsivity, hostility and sensation seeking influenced the relationship between the 5-HTTLPR polymorphism and PRL response to m-CPP in this sample. Individuals with the SS genotype showed significantly heightened PRL response to the challenge compared with the LL and LS genotypes. No influence of gender or substance abuse condition was observed. Hostility was associated with blunted PRL response in the total sample. Cocaine abuse was the most significant moderator of DeltaPRL (peak PRL-baseline PRL), and the interaction of genetic, behavioral and psychopathological measures helped predict most of the observed DeltaPRL (62.5%). Although these results need replication, variation in the 5-HTTLPR gene appears to influence measures of 5-HT function and interact with disease state and personality dimensions to account for 5-HT disturbances in African-American populations.

Developmental psychopathology and neurobiology of aggression

The aim of this paper is to clarify how neural mechanisms at the molecular level, specifically the serotonergic (5-HT) system and the hypothalamic-pituitary-adrenal axis system (HPA) in conjunction with early life stress may contribute to the emergence of aggression, self-directed and otherwise, in borderline personality disorder (BPD). Chronic dysregulation of these biological systems, which function to regulate stress and emotion, may potentiate the development of impulsive aggression in borderline personality conditions. Our central premise in this paper is that brain development, stress regulation, and early pathonomic experience are interactive and cumulative in their mutual influence on the development of impulsive aggression in BPD. We review the parameters of impulsive aggression in BPD, followed by a discussion of the neurobiological and neuroendocrine correlates of impulsive aggression with and without BPD. We then focus on the developmental continuities in BPD with attention to brain maturation of 5-HT and HPA axis function during the life span and the influence of early adverse experiences on these systems. Finally, we comment on the data of the relative stability of aggression in BPD, adolescence as a developmental stage of potential vulnerability, and the course of aggressive behavior during the life span.

Depression and antisocial personality disorder: two contrasting disorders of 5HT function

Impaired 5HT functioning has been implicated in two very different psychiatric syndromes: antisocial personality disorder and depression. In both, reduced csf concentration of 5HIAA and blunted circulating hormone responses to 5HT drug challenge have been described. The paradox can be resolved by the theory that the two main ascending 5HT pathways mediate adaptive responses to future and current adversity. Projections of the anterior group of raphe 5HT cells (dorsal raphe nucleus) oppose the action of dopamine and mediate avoidance of threats. Impaired function sensitises the dopamine system resulting in impulsivity and drug addiction. Posterior 5HT cells (median raphe nucleus) innervate hippocampus and cingulate gyrus and suppress memory and awareness of current and past adversity. Impaired function results in low mood, low self-esteem, hopelessness and pessimism. Modern imaging methods are providing startling corroboration of these ideas.

Is long-term heavy alcohol consumption toxic for brain serotonergic neurons? Relationship between years of excessive alcohol consumption and serotonergic neurotransmission

The relationship between years of excessive alcohol consumption and central serotonergic neurotransmission, as assessed by the prolactin (PRL) response to D-fenfluramine, was investigated in 22 male alcohol-dependent subjects. A negative correlation was obtained, that is, the longer duration of excessive alcohol consumption the lower PRL response to D-fenfluramine. It is therefore suggested that long duration of excessive alcohol consumption in alcohol-dependent subjects causes a reduction in central serotonergic neurotransmission, possibly by a toxic effect of alcohol on serotonin neurons. The relationship between depressive and anxiety symptoms during on-going drinking and the PRL response to D-fenfluramine was also investigated. No such correlations were obtained, suggesting that reduction in central serotonergic neurotransmission does not pre-dispose to the development of depressive and anxiety symptoms, at least in relation to on-going drinking in alcohol-dependent subjects.

Dopamine receptor responsivity in alcoholic patients before and after detoxification

OBJECTIVE

To assess central dopamine receptor responsivity in alcoholic patients during their usual alcohol consumption and after detoxification.

METHOD

Plasma prolactin levels were measured at 0, 30, 60, and 90 min after administration of 5 mg haloperidol i.m. in 21 hospitalized male alcoholic patients during usual alcohol consumption, and 13 days later (mean, range 7-17 days), after detoxification. The test was also performed in seven healthy male volunteers. The patterns of prolactin responses were compared using repeated measures analysis of variance.

RESULTS

The prolactin responses to haloperidol increased significantly after detoxification compared to those during usual alcohol consumption (state x time interaction P < 0.01; planned comparisons for times 0 and 90 min between states P = 0.03). Compared to controls, the responses of the patients before detoxification were lower (group-time interaction P = 0.001), and the difference was not significant after detoxification (P = 0.19). The magnitude of plasma prolactin (PRL) responses were not related to duration of alcohol abuse, score in the Brief Michigan Alcoholism Screening Test (BMAST) scale, or family history of alcoholism.

CONCLUSIONS

Alcohol detoxification is accompanied by a normalization of the low responsivity of central dopaminergic receptors during alcohol abuse. The data support the hypothesis of a participation of the central dopaminergic system in alcohol dependence.

Ipsapirone neuroendocrine challenge: relationship to aggression as measured in the human laboratory

Thirty-one human subjects were administered a neuroendocrine challenge with the 5-HT1a agonist ipsapirone after completing six sessions of a laboratory measure of aggression, the Point Subtraction Aggression Paradigm (PSAP), in order to determine if a laboratory measure of aggression was related to serotonin function. Subjects who showed more aggressive responding on the PSAP (n = 11) had a significantly blunted temperature response to ipsapirone compared to those with less aggressive responding (n = 20). There was no difference between the two groups on the cortisol response to ipsapirone. This study supports a relationship between serotonin function and aggression as measured in the human laboratory, similar to the well-documented association between self-reported aggression and serotonin.

Hostility is associated with a heightened prolactin response to meta-chlorophenylpiperazine in abstinent cocaine addicts

The prolactin (PRL) response to the administration of serotonin (5HT) agonists is an index of central nervous system 5HT activity. This index is blunted in association with hostile aggression in personality and depressive disorder patients without substance abuse. We tested whether the PRL response to the oral administration of the partial 5HT agonist meta-chlorophenylpiperazine (MCPP), 0.35 mg/kg, was associated with a measure of trait hostility, the Buss Durkee Hostility Inventory (BDHI), in cocaine addicts who were completing a 3-week detoxification and rehabilitation program. We also tested whether the cocaine addicts differed from healthy volunteers on their PRL, cortisol (CORT) or temperature responses to MCPP. The PRL response to MCPP was positively associated with the total score on the BDHI. There were, however, no differences in the neuroendocrine or temperature responses to MCPP between the cocaine-dependent group and the healthy volunteers once age effects were controlled for.