Cerebrospinal fluid inflammatory cytokines and aggression in personality disordered subjects.

BACKGROUND: Neurochemical studies have pointed to a modulatory role in human aggression for a variety of central neurotransmitters and neuromodulators such as cytokines. While animal studies of cytokines suggest an aggression-facilitating role for central cytokines, especially for interleukin-1ß and other cytokines, no cerebrospinal fluid studies of cytokines have yet been reported in regard to human aggression. METHODS: Basal lumbar cerebrospinal fluid samples were obtained from 38 physically healthy subjects with DSM-5 Personality Disorder and assayed for cerebrospinal fluid interleukin-6 (log IL-6) and cerebrospinal fluid soluble IL-1 Receptor II protein in the context of their relationship with measures of aggression. RESULTS: Cerebrospinal fluid soluble interleukin-1 Receptor II (r=.35, r(2) = .12, P= .03), but not log interleukin-6 (r = -.05, r(2) = .00, P= .76), levels were positively correlated with a composite measure of aggression. Adding relevant covariates, including cerebrospinal fluid levels of serotonin and dopamine metabolites, to the statistical model doubled the strength of this relationship (partial r = .54, r(2) = .29, P= .002). No relationship was seen with history of suicidal behavior or with any measure of impulsivity, negative affectivity, or of general dimensions of personality. CONCLUSION: These data suggest a positive relationship between at least one inflammatory cytokine in the central nervous system and aggression in human subjects. This finding adds to the complex picture of the central neurochemistry of impulsive aggression in human subjects.

Cerebrospinal fluid and plasma C-reactive protein and aggression in personality-disordered subjects: a pilot study.

C-reactive protein (CRP), in the plasma, serves as a marker of systemic inflammation and has been shown to correlate with history of actual aggressive behavior, and as a personality trait of aggressive tendency, in human subjects. This pilot study was conducted to determine if plasma CRP levels are correlated with cerebrospinal fluid levels (CSF CRP) and if CSF CRP also correlates with aggression. If so, this would suggest a role for central inflammatory processes in human aggression. Both plasma and basal lumbar CSF samples were obtained from 17 subjects with DSM-5 personality disorder and assayed for CRP. Plasma and CSF CRP levels were correlated (r = 0.65, p = 0.005) and each correlated with aggression (Plasma: r = 0.53, p = 0.029; CSF: r = 0.84, p < 0.001). When considered simultaneously, CSF CRP, but not plasma CRP, uniquely correlated with aggression. No relationship was seen with other measures of psychopathology. These data suggest a positive relationship between central nervous system CRP and aggression in humans.

Cerebrospinal fluid 5-hydroxyindolacetic acid correlates directly with negative affective intensity, but not affective lability, in human subjects.

Centrally acting monoamines have long been thought to be associated with component traits of behavior and emotion and are potential biological mediators of psychopathology. In this study we tested the hypothesis that centrally acting monoamines would be associated with measures of affective instability (i.e. affective intensity and affective lability) in healthy and personality disordered human subjects. In total, 57 adult subjects including 19 psychiatrically healthy volunteers and 38 personality disordered individuals were assessed for affective instability with the affective intensity measure (AIM) and the Affective Lability Scale (ALS). Samples of cerebrospinal fluid (CSF) were collected for assay of 5-hydroxyindoleacitic acid (5-HIAA), homovanillic acid (HVA) and 3-methoxy-4-hydroxy-phenylglycol (MHPG). CSF 5-HIAA concentration correlated directly with overall AIM score and, specifically, with the AIM Negative Intensity score, in all subjects and in personality disordered subjects. This result was not affected but the addition of aggression scores or life history of mood disorder to the model. Neither CSF HVA nor MHPG were found to uniquely correlate with either AIM or ALS measure. Higher Affective Intensity scores, Negative Intensity scores, specifically, are directly correlated with higher basal levels of CSF 5-HIAA. This relationship was independent of aggression, life history of mood disorder and general personality traits.

Cerebrospinal fluid 5-hydroxyindolacetic acid and homovanillic acid: reciprocal relationships with impulsive aggression in human subjects.

While the relationship between cerebrospinal fluid 5-HIAA (CSF 5-HIAA) and aggression is typically reported as inverse, studies of some groups of aggressive individuals demonstrate a positive (or no) relationship, between these two variables. It is possible that simultaneous examination of both CSF 5-HIAA and CSF homovanillic acid (HVA), which co-vary in human subjects may clarify differences in reported findings in different groups of aggressive individuals. CSF 5-HIAA and CSF HVA concentrations were simultaneously examined in 60 healthy human subjects (40 with personality disorder and 20 healthy controls) and were correlated with measures of aggression and impulsivity. CSF 5-HIAA concentrations correlated positively, and CSF HVA concentrations correlated inversely, with a composite measure of impulsive aggression in all subjects as well as in the personality disordered subjects. The CSF 5-HIAA findings are consistent with those demonstrating reduced post-synaptic 5-HT receptor responsiveness to 5-HT agent challenge and suggest differences in the pathophysiology between different groups of subjects with aggressive behavior, particularly with regard to severity of aggressive behavior.

Cerebrospinal fluid GABA concentration: relationship with impulsivity and history of suicidal behavior, but not aggression, in human subjects.

The objective of this study was to assess the relationship between cerebrospinal fluid concentrations of the neurotransmitter gamma-aminobutyric acid (GABA) and measures of impulsivity and related behaviors (aggression and suicidality) in healthy volunteer and personality disordered subjects. CSF GABA levels, and measures of impulsivity, aggression, and history of suicidal behavior were obtained by morning lumbar puncture in 57 healthy volunteer subjects and in subjects with personality disorder. CSF GABA levels were not found to correlate with measures of aggression but were found to correlate directly with measures of impulsivity; e.g., a composite measure of impulsivity in all subjects (r=0.35, df=46, P=0.015) and in personality disordered subjects examined separately (r=0.39, df=30, P=0.029). In the personality disorder group, CSF GABA levels were higher among subjects with a history of suicidal behavior compared with those without this history. These data suggest that central GABAergic function correlates directly with impulsiveness and history of suicidal behavior, but not aggressiveness, in personality disordered subjects. This may be consistent with observations that high doses of benzodiazepines can lead to "behavioral disinhibition" in human subjects. Further work assessing this and other aspects of the central GABA system in personality disordered subjects are warranted.

CSF corticotropin-releasing factor in personality disorder: relationship with self-reported parental care.

This cross-sectional investigation tests the relationship between the level of self-reported childhood parental care and cerebrospinal fluid (CSF) corticotropin-releasing factor (CRF) concentration in adults with and without personality disorder (PD). Based on preclinical models of the lasting effect of post-natal parental care on central CRF function, the primary hypothesis was that childhood parental care, as reflected by the parental bonding inventory (PBI) care and involvement subscale, is inversely correlated with adult CSF CRF levels. The sample includes cerebrospinal fluid CRF samples from 19 subjects who were included in a previously published report on the relationship between CRF level and Childhood Trauma Questionnaire score. Parental bonding was measured retrospectively with the PBI in 54 medication-free male and female subjects, 37 of whom were diagnosed with a DSM-IV PD, 17 of whom were normal controls free of Axis I and II psychopathology. CSF CRF level as measured by lumbar puncture was entered into a model as the dependent variable, with the independent variables of PBI Parental Care and Involvement, diagnostic category, age, and gender. The model predicting CSF CRF level was significant, with PBI parental care and involvement negatively correlated with CSF CRF level. PD subjects with higher than median PBI parental care and involvement score had significantly lower CSF CRF levels than both normal controls and PD subjects with lower than median PBI parental care and involvement. Higher levels of self-report parental care predict lower CSF CRF levels in PD subjects, consistent with a beneficial effect of parental care on decreased stress reactivity, and consistent with previous reports in humans. The cross-sectional design of the study, however, limits causal inferences.

Childhood trauma and personality disorder: positive correlation with adult CSF corticotropin-releasing factor concentrations.

OBJECTIVE: To test the hypothesis that early life trauma results in adult stress hormone alterations in individuals with personality disorders, the authors examined the relationship between history of childhood adversity and lumbar CSF corticotropin-releasing factor (CRF). METHOD: Participants were 20 otherwise healthy men who met DSM-IV criteria for personality disorders. CSF CRF was obtained by lumbar puncture, and childhood adversity was measured by the Childhood Trauma Questionnaire. Correlations were obtained between CSF CRF and the total score on the Childhood Trauma Questionnaire as well as scores on its four subscales. RESULTS: CSF CRF concentrations were positively correlated with the total score on the Childhood Trauma Questionnaire. Analysis of the subscales revealed that CSF CRF was correlated with emotional neglect. Correlations between CSF CRF level and physical and emotional abuse and with physical neglect were not statistically significant. CONCLUSIONS: Consistent with the hypothesis that the severity of early life stress is correlated with stress hormone abnormalities in adulthood, Childhood Trauma Questionnaire total scores and emotional neglect scores were significantly correlated with CSF CRF levels in individuals with personality disorders.

Dopamine beta-hydroxylase in CSF. Relationship to personality measures.

Dopamine beta-hydroxylase (DBH), the enzyme that converts dopamine to norepinephrine, was measured in the CSF of 32 subjects. Those individuals with a low level of DBH in the CSF had significantly elevated profiles on the Minnesota Multiphasic Personality Inventory, suggesting a relationship between the central noradrenergic system and some aspects of personality in man.

Cerebrospinal fluid vasopressin levels: correlates with aggression and serotonin function in personality-disordered subjects.

BACKGROUND: Animal studies suggest that central vasopressin plays a facilitatory role in aggressive behavior. To examine this possibility in humans, the relationship between cerebrospinal fluid (CSF) arginine vasopressin (AVP) and indices of aggression and central serotonin system function was examined in personality-disordered subjects. METHODS: We used CSF (AVP), CSF 5-hydroxyindoleacetic acid, and the prolactin response to d-fenfluramine challenge (PRL[d-FEN]) as central indices of vasopressin and serotonergic system function, respectively, in 26 subjects who met the DSM-IV criteria for personality disorder. Measures of aggression and impulsivity included the Life History of Aggression assessment and the Barratt Impulsiveness Scales. RESULTS: The CSF AVP level was correlated directly with life history of general aggression and aggression against persons and inversely with PRL[d-FEN] responses (but not with CSF 5-hydroxyindoleacetic acid), which in turn was correlated inversely with these 2 measures of life history of aggression. The positive relationship between CSF AVP and life history of aggression remained even when the variance associated with PRL[d-FEN] responses in these subjects was accounted for. CONCLUSION: Central AVP may play a role in enhancing, while serotonin plays a role in inhibiting, aggressive behavior in personality-disordered individuals. In addition to the possibility of central AVP and serotonin interacting to influence human aggression, central AVP may also influence human aggressive behavior through a mechanism independent of central serotonin in personality-disordered subjects.

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.

Central serotonin activity and aggression: inverse relationship with prolactin response to d-fenfluramine, but not CSF 5-HIAA concentration, in human subjects.

OBJECTIVE: This study compared the nature and magnitude of the relationship between aggression and CSF 5-hydroxyindoleacetic acid (5-HIAA) concentration with that between aggression and the prolactin response to d-fenfluramine challenge in human subjects. METHOD: The Life History of Aggression assessment scores of 24 subjects with personality disorders were compared with their lumbar CSF 5-HIAA concentrations and with their prolactin responses to d-fenfluramine challenge. RESULTS: Aggression was significantly and inversely correlated with prolactin responses to d-fenfluramine challenge but not with lumbar CSF 5-HIAA concentrations in these subjects. CONCLUSIONS: Prolactin response to d-fenfluramine may be more sensitive than lumbar CSF 5-HIAA concentration in detecting a relationship between aggression and central serotonin activity in noncriminally violent human subjects.

Rorschach ratings in depressed and suicidal patients with low levels of 5-hydroxyindoleacetic acid in cerebrospinal fluid.

In order to explore the psychodynamics of a previously observed association between a low concentration of the serotonin metabolite 5-hydroxyindoleacetic acid (5-HIAA) in cerebrospinal fluid (CSF) and an increased tendency to suicidal behavior, blind ratings of Rorschach variables were compared between depressed and/or suicidal patients with low (less than 80 nanomoles/l) and normal (greater than 80 nanomoles/l) CSF 5-HIAA. In 14 patient pairs matched for sex, age, body height, and interview-based ratings of severity of depression, the low 5-HIAA subjects had significantly more anxiety and more hostility in the Rorschach ratings. Their anxiety tolerance was lower, and they were significantly less efficient in their handling of conflict. The results support the hypothesis that biochemical variables may be of importance for certain psychodynamic mechanisms suggested to be relevant for psychopathology, including suicidal behavior.

Serotonin function in human subjects: intercorrelations among central 5-HT indices and aggressiveness.

Three central indices of serotonin (5-HT) system activity in human subjects were examined to: (a) estimate intercorrelations among 5-HT indices and (b) compare correlations of these indices with a measure of assaultiveness (Buss-Durkee 'Assault') in personality-disordered individuals. Cerebrospinal fluid (CSF) 5-hydroxyindoleacetic acid (5-HIAA) concentration and prolactin responses to m-chlorophenylpiperazine (m-CPP) m-CPP (PRL[m-CPP]) and fenfluramine (PRL[FEN]), served as indices of pre-, post- and 'net'-synaptic central 5-HT activity, respectively. PRL[D,L-FEN] responses were inversely related to CSF 5-HIAA concentration and positively correlated with PRL[m-CPP] responses. Both PRL[D,L-FEN] and PRL[m-CPP] response data correlated equally, and inversely, with BD Buss-Durkee Assault when the same subjects were examined. Basal CSF 5-HIAA concentration did not correlate with Buss-Durkee 'Assault'. PRL responses to challenge probes which involve activation of 5-HT post-synaptic receptors may correlate better than a basal measure of pre-synaptic 5-HT function with a tendency to assaultive behavior in non-criminally aggressive personality-disordered individuals.

Cerebrospinal fluid 5-hydroxyindoleacetic acid as an index of central serotonergic processes.

Faulty transmission in the central serotonin and catecholamine systems may be involved in some psychiatric and neurological conditions. Central monoamine metabolism can be studied by measuring amine metabolites in the lumbar cerebrospinal fluid (CSF), but results to date have been inconsistent. Since most studies have analyzed lumbar CSF, one reason for the inconsistencies may be that lumbar fluid does not reflect brain amine metabolism. We measured 5-hydroxyindoleacetic acid (5HIAA) and homovanillic acid (HVA) in serial CSF samples obtained in connection with pneumoencephalographic (PEG) examinations: through seven samples of equal volume, a gradual increase was found for both metabolites in 14 neurological patients, and the first and last fractions were statistically significantly correlated. In addition, a small series of cisternal CSF samples from psychiatric (depressed and alcoholic) and neurological patients were analyzed for 5HIAA. Frequency distribution in cisternal CSF was similar to that of lumbar values, although the levels were about twice as high, close to those found in the last PEG fractions. There were no significant differences between patient groups either in cisternal or lumbar CSF 5HIAA. These findings suggest that while there is an ascending gradient, lumbar CSF samples do reflect amine metabolite concentrations of the more central fluid. No disease-specific differences in cisternal CSF were found which were absent in the lumbar fluid.

Cerebrospinal fluid neuropeptide Y-like immunoreactivity correlates with impulsive aggression in human subjects.

BACKGROUND: Neurochemical studies have pointed to a modulatory role in human aggression for a number of central neurotransmitters; some (e.g., serotonin) appear to play an inhibitory role, while others (e.g., vasopressin) appear to play a facilitator role in the modulation of aggression. While recent animal studies of neuropeptide Y (NPY) have suggested a facilitator role for central NPY in the modulation of aggression, no human studies of central NPY have yet been reported regarding aggression. METHODS: Basal lumbar cerebrospinal fluid (CSF) was obtained from 60 physically healthy subjects with personality disorder (PD) (n=40) and from healthy volunteers (n=20). These samples were then assessed for CSF NPY-like immunoreactivity (NPY-LI) and other neurotransmitter-related species in CSF and correlated with measures of aggression and impulsivity. RESULTS: Cerebrospinal fluid NPY-LI was higher in PD subjects compared with healthy volunteers and in subjects with intermittent explosive disorder compared with those without intermittent explosive disorder. In PD subjects, CSF NPY-LI was directly correlated with composite measures of aggression and impulsivity and a composite measure of impulsive aggression. Group differences in CSF NPY-LI concentration were accounted for by measures of impulsive aggression. CONCLUSIONS: These data suggest a direct relationship between CSF NPY-immunoreactivity concentration and measures of impulsive aggression in human subjects. This adds to the complex picture of the central neuromodulatory role of impulsive aggression in human subjects.

Cerebrospinal fluid substance P-like immunoreactivity correlates with aggression in personality disordered subjects.

BACKGROUND: Neurochemical studies have pointed to a modulatory role in human aggression for a variety of central neurotransmitters; some seem to play an inhibitory role, whereas others seem to play a facilitory role in the modulation of aggression. Laboratory animal studies of substance P suggest a facilitory role for this undecapeptide in the modulation of aggression, but no studies of substance P have yet been reported with regard to human aggression. METHODS: Basal lumbar cerebrospinal fluid samples were obtained from 38 physically healthy subjects with personality disorder (PD) and substance P-like immunoreactivity was measured and correlated with measures of aggression and impulsivity. RESULTS: The cerebrospinal fluid substance P-like immunoreactivity levels were directly correlated with a composite measure of aggression and, more specifically, with Buss-Durkee Aggression. No correlation was seen with any measure of impulsivity or of general dimensions of personality. CONCLUSIONS: These data suggest a direct relationship between central nervous system substance P containing neural circuits and aggression in human subjects. This finding adds to the complex picture of the central neuromodulatory role of impulsive aggression in human subjects.

The neuroendocrinology of childhood trauma in personality disorder.

BACKGROUND: Childhood trauma has been associated with elevated central corticotropin releasing hormone (CRH) drive in adults meeting general DSM-IV criteria for personality disorder. It is not clear how this may be related to pituitary or adrenal responsiveness in personality disorder. It was hypothesized that high levels of childhood trauma would be associated with blunted cortisol and adrenocorticotropin releasing hormone (ACTH) response to the combined dexamethasone(DEX)/CRH test in adults meeting general DSM-IV criteria for personality disorder. METHOD: 24 healthy, medication free adults with personality disorder (N=16) and a group of healthy controls (N=8) underwent semi-structured diagnostic interviews and completed the Childhood Trauma Questionnaire (CTQ). Across two separate study sessions separated by at least a week, cerebrospinal fluid (CSF) was sampled by lumbar puncture for measurement of CRH concentration (N=17), and peripheral blood cortisol and ACTH levels were measured after challenge with DEX/CRH (N=24). RESULTS: As hypothesized, high CTQ score was associated with a blunted cortisol and ACTH response to DEX/CRH challenge. Indices of cortisol and ACTH response (peak level and area under the curve (AUC)) to DEX/CRH were in turn significantly negatively correlated with CSF CRH concentration. CONCLUSION: Childhood trauma in adults with personality disorder is associated with blunted cortisol and ACTH secretion following DEX/CRH challenge. These effects are independent of depression or posttraumatic stress disorder. Previous work would suggest that blunted pituitary-adrenal response is related to elevated central CRH drive. Corroborating this, CSF CRH levels were significantly and negatively correlated with peak level and AUC of both cortisol and ACTH.

Non-suicidal self-injurious behavior, endogenous opioids and monoamine neurotransmitters.

BACKGROUND: Self-inflicted injury, including cutting or burning, is the most frequent reason for psychiatric visits to medical emergency departments. This behavior, particularly when there is no apparent suicidal intent, is poorly understood from both biological and clinical perspectives. OBJECTIVE: To examine the role of endogenous opioids and monoamine neurotransmitters in non-suicidal self-injury (NSSI). METHODS: We compared cerebrospinal fluid (CSF) levels of endogenous opioids, 5 hydroxyindolacetic acid (5-HIAA) and homovanillic acid (HVA) in individuals with a history of repetitive non-suicidal self-injury with a diagnostically-matched group of individuals who had never engaged in non-suicidal self-injury. History of suicidal behavior, demographic background and psychopathology was assessed. All patients were diagnosed with a Cluster B personality disorder (i.e. borderline, antisocial, narcissistic or histrionic) (N=29) and had a history of at least one suicide attempt. Fourteen participants had a history of repeated non-suicidal self-injurious behavior (NSSI) in adulthood and 15 did not (no NSSI). RESULTS: The NSSI group had significantly lower levels of CSF beta-endorphin and met-enkephalin when compared with the non-NSSI group. CSF dynorphin, HVA and 5-HIAA levels did not differ. Severity of depression, hopelessness and overall psychopathology was greater in the NSSI group. CONCLUSION: beta-endorphin and met-enkephalin, opioids acting upon receptors involved in mediating stress-induced and physical pain analgesia respectively, are implicated in NSSI. Serotonergic and dopaminergic dysfunctions do not appear to be related to NSSI. Based on our findings, we propose a model of non-suicidal self-injury. Our results suggest that drugs acting on the opioid system warrant exploration as pharmacological treatments for NSSI.