Plasma neurochemistry in juvenile offenders

Serotonin and aggressive behaviour in children and adolescents: a systematic review

OBJECTIVE

The role of serotonin (5-HT) in human aggression has been the subject of a large number of studies, mostly with adults. Meta-analyses indicate a small but significant inverse relationship between central nervous 5-HT availability and aggression, but genetically informed studies suggest two pathways: one to reactive aggression and the other to proactive aggression.

METHOD

We conducted a systemic review on central nervous 5-HT function in children and adolescents, with attention to the function of aggression.

RESULTS

In total, 675 articles were screened for relevance, with 45 reviewed. These included blood assays (e.g. plasma, 5-HIAA; platelet 5-HTR_2A ), epigenetic studies, retrospective PET studies and 5-HT challenge paradigms (e.g. tryptophan depletion). Overall, findings were mixed, with support both for negative and for positive associations of central nervous 5-HT function with aggression in children and adolescents.

CONCLUSION

We propose factors that may be blurring the picture, including problems in the conceptualization and measurement of aggression in young people, the lack of prospective designs and the bias towards clinical samples of boys. Research needs to account for variance in the both motivation for and implementation of aggression, and look to the behavioural economics literature to consider the roles of reward, vengeance and self-control more clearly.

Serotonin and Female Psychopathology

There are sex differences in the prevalence and presentation of many psychiatric disorders. Various trends in symptomatology have emerged that are thought to be linked to periods of hormonal fluctuations such as with menses, pregnancy or menopause. With data from animal and human studies, it has become clear that there is an important interplay between the serotonergic system and gonadal hormones. The majority of the research to date has focused on the influence that estrogen has within the CNS and, in particular, how it leads to an overall increase in serotonin synthesis and availability. In reviewing this female-specific topic we hope to raise awareness to sex/gender differences in psychopathology, help identify at-risk populations and consider development of new treatment options. Future research will also need to consider the influence that progesterone and oxytocin may have on sex-specific psychopathology as well as incorporate neuroimaging and consider the influence of hormones on the serotonergic system at a genetic level.

The neurobiology of oppositional defiant disorder and conduct disorder: altered functioning in three mental domains

This review discusses neurobiological studies of oppositional defiant disorder and conduct disorder within the conceptual framework of three interrelated mental domains: punishment processing, reward processing, and cognitive control. First, impaired fear conditioning, reduced cortisol reactivity to stress, amygdala hyporeactivity to negative stimuli, and altered serotonin and noradrenaline neurotransmission suggest low punishment sensitivity, which may compromise the ability of children and adolescents to make associations between inappropriate behaviors and forthcoming punishments. Second, sympathetic nervous system hyporeactivity to incentives, low basal heart rate associated with sensation seeking, orbitofrontal cortex hyporeactiviy to reward, and altered dopamine functioning suggest a hyposensitivity to reward. The associated unpleasant emotional state may make children and adolescents prone to sensation-seeking behavior such as rule breaking, delinquency, and substance abuse. Third, impairments in executive functions, especially when motivational factors are involved, as well as structural deficits and impaired functioning of the paralimbic system encompassing the orbitofrontal and cingulate cortex, suggest impaired cognitive control over emotional behavior. In the discussion we argue that more insight into the neurobiology of oppositional defiance disorder and conduct disorder may be obtained by studying these disorders separately and by paying attention to the heterogeneity of symptoms within each disorder.

The heterogeneity of disruptive behavior disorders - implications for neurobiological research and treatment

Disruptive behavior disorders (DBDs) are reflected by a great variety of symptoms ranging from impulsive-hot-tempered quarrels to purposeful and goal-directed acts of cruelty. A growing body of data indicates that there are neurobiological factors that increase the risk for developing DBDs. In this review, we give a broad overview of recent studies investigating physiological, neural, genetic factors, and specific neurotransmitter systems. We also discuss the impact of psychosocial risk and consider the effects of gene-environment interactions. Due to the heterogeneity of DBDs, it is concluded that specific subtypes of disruptive behavior should be considered both in terms their biological basis and in regard to specific treatment needs.

Platelet poor plasma serotonin level in delinquent adolescents diagnosed with conduct disorder

OBJECTIVE

Accumulating data indicate the involvement of the serotonergic system in adolescent aggression. The aim of this study was to examine the platelet-poor plasma (PPP) serotonin (5-HT) levels among delinquent adolescent boys with conduct disorder (CD) in comparison with normal controls.

METHOD

PPP 5-HT levels were measured in 16 male delinquent CD adolescents from a correctional facility and in 14 normal male adolescent controls. Severity of aggressive behavior was assessed by the Child Behavior Checklist (CBCL) and the Overt Aggression Scale (OAS).

RESULTS

Delinquent CD adolescents had higher PPP 5-HT levels (about 3-fold) than the normal controls (27.68+/-32.29 vs. 7.76+/-4.23 ng/ml, respectively, p=0.027). In the delinquent CD adolescents a significant correlation was found between the PPP 5-HT levels and the CBCL and OAS aggressive scores (r=0.68, p=0.0034 and r=0.59, p=0.016, respectively).

CONCLUSIONS

Juvenile delinquency is associated with high PPP 5-HT levels. Modulation of 5-HT neurotransmission may have a role in the symptomatology and treatment of severe adolescent CD.

Serotonin effects on sleep and emotional disorders in adolescent migraine

OBJECTIVE

To determine frequency of emotional disorders and sleep disturbances in adolescent migraineurs with episodic and chronic headaches. To determine the relationship of whole blood serotonin, caffeine consumption, and frequency of sleep and mood disorders.

BACKGROUND

The neurotransmitter serotonin has been implicated to play a role in the initiation and maintenance of sleep and in modulating mood. A putative role in migraine pathophysiology is also known.

METHODS

Adolescents from 13 to 17 years of age were identified from our headache clinic with episodic or chronic migraine (according to International Classification of Headache Disorders-Second Edition criteria) and healthy controls enrolled. Psychological rating scales were completed, including Adolescent Symptom Inventory (4th Edition) and Child Depression Inventory. Sleep questionnaires (Pediatric Sleep Questionnaire and Child Sleep Habit Questionnaire) were completed by the teenager's parents/guardian. Whole blood serotonin levels were drawn and analyzed and caffeine consumption obtained by history.

RESULTS

A total of 18 controls (8 girls) and 15 patients each with episodic migraines (9 girls) and chronic migraine (10 girls) were studied. Patients with headache had significantly more sleep problems than controls. Patients with chronic migraines had increased daytime sleepiness and dysthymia compared with teenagers with episodic migraines. Serotonin levels were not significantly different, and no association was noted between serotonin levels and sleep abnormalities or emotional rating scales. Increased caffeine intake was related to sleep and depressive complaints.

CONCLUSIONS

Sleep and emotional disorders were common in adolescents with migraine. Sleep disorders and dysthymia were more prevalent with increased headache frequency. No correlation was noted with whole blood serotonin levels.

How can the study of biological processes help design new interventions for children with severe antisocial behavior?

Children with severe antisocial behavior have an increased risk of showing violently aggressive and other forms of problem behavior in adolescence and adulthood. It is well established that both biological and social factors are involved in the development of antisocial behavior. The primary aim of this paper is to discuss the evidence that specific neurobiological systems are involved in the etiology of childhood-onset antisocial behavior. These factors are responsible for the severity of the behavioral problems observed in antisocial children, but they also play a role in their persistence, because they influence children's interactions with their environment. We will discuss the possible causes of disruptions in neurobiological systems in childhood antisocial behavior and point out the implications of these findings for theory and clinical practice. We will argue that familial factors (e.g., genetic influences, early childhood adversity) are linked to negative behavioral outcomes (e.g., antisocial behavior problems) through the mediating and transactional interplay with neurobiological deficits. An investigation of neurobiological functioning in antisocial children might not only indicate which children are most likely to persist in engaging in severe antisocial behavior, but also guide the development of new interventions.

Influence of rapid tryptophan depletion on laboratory-provoked aggression in children with ADHD

BACKGROUND

The present study investigated the effects of rapid tryptophan depletion (RTD), and the ensuing reduction of central nervous system levels of serotonin (5-HT), upon reactive aggression in patients with attention deficit/hyperactivity disorder (ADHD). Furthermore, it was asked whether the relation between 5-HT function and behavioural aggression in patients is influenced by their age, the intensity of their attention problems or their comorbid symptoms.

METHODS

The study employed a double-blind, within-subject crossover design. On day 1, 22 male adolescent patients with ADHD were subjected to RTD and the subsequent reduction of central 5-HT levels. On day 2, they received a tryptophan-balanced amino acid mixture (BAL), which acted as a placebo. On both days, 4.5 h after the intake of the RTD/BAL amino acids, reactive aggressive behaviour was provoked using a competitive reaction time game, which consisted of both high and low provocation conditions.

RESULTS

The number of aggressive responses was significantly higher after low provocation during acute tryptophan depletion, in comparison to the placebo. Furthermore, this study provides evidence that neither age nor the intensity of attention symptoms in ADHD patients had an impact on the relation between 5-HT and reactive aggression.

CONCLUSION

This study indicates that in children with ADHD, there is an inverse relationship between 5-HT and aggression.

Neuroendocrine and neurotransmitter correlates in children with antisocial behavior

When antisocial behavior becomes a persistent pattern that affects diverse domains of children's functioning, psychiatrists refer to oppositional defiant disorder (ODD) or conduct disorder (CD). The term disruptive behavior disorder (DBD) covers both ODD and CD. Research shows that in the absence of effective interventions, the prognosis for DBD children is relatively unfavorable: their disorder can extend into adolescence, manifest itself in delinquency, and convert into other psychiatric symptoms, such as addiction or personality disorders. Although environmental factors have traditionally attracted most attention in explaining the origin and persistence of DBDs, it is important not to overlook the vulnerability of the child in the development of antisocial behavior. Relatively few studies have been conducted on the neurobiological factors involved in the development of DBDs in children. In this paper, we explain how problems in hypothalamic-pituitary-adrenal (HPA) axis and serotonergic system functioning could be important factors in the behavioral problems of DBD children. Low fear of punishment and physiological underactivity may predispose antisocial individuals to seek out stimulation or take risks and may explain poor (social) conditioning and socialization. Findings consistent with this hypothesis are presented. Finally, we explain how stress in general, and adverse early life experiences in particular, could have an impact on the development of the HPA and serotonergic systems. An investigation of the neurobiological factors involved in antisocial behavior disorder might ultimately guide the development of new forms of intervention.

Platelet serotonin content correlates inversely with life history of aggression in personality-disordered subjects

The objective of this study was to test the hypothesis that platelet serotonin (5-hydroxytryptamine, 5-HT) content is correlated with measures of aggression in healthy human subjects. Platelet 5-HT content (ng/mg protein) was measured in personality-disordered (PD) and normal control (NC) subjects. Aggression was assessed with the Life History of Aggression (LHA), the Buss-Durkee Hostility Inventory (BDHI), and the Motor Aggression and Research Criteria for Intermittent Explosive Disorder (IED-IR); impulsivity was assessed with the Eysenck Personality Questionnaire II (EPQII) and the Barratt Impulsiveness Scale (BIS-11). LHA Aggression, but not impulsivity, scores showed significant inverse correlations with platelet 5-HT content in all subjects or in PD subjects alone. The findings in PD subjects remained significant after co-varying for race. PD subjects with IED-IR had lower platelet 5-HT content compared with PD subjects who did not have IED-IR, although this finding only approached significance after controlling for race. This study demonstrates an association between reduced platelet 5-HT content and aggression in PD subjects. Similar to other studies of platelet 5-HT markers, these data suggest that platelet 5-HT content may also reflect central 5-HT alterations and may be used as a biological marker in appropriate patient samples.

Thrombozytäre Serotoninkonzentration bei depressiven Kindern und Jugendlichen

Zusammenfassung: Fragestellung: In dieser Studie wurde der Frage nachgegangen, inwieweit ein Zusammenhang zwischen thrombozytärem Serotoningehalt und depressivem bzw. suizidalem Verhalten bei Kindern und Jugendlichen besteht. Methodik: Innerhalb von 16 Monaten wurde bei allen stationär aufgenommenen Patienten im Alter von 4 bis 19 Jahren (n = 145) das thrombozytäre Serotonin mittels Fluoreszenzspektroskopie bestimmt. Zeitnah wurde bei einem Teil der Patienten der Schweregrad der depressiven Symptome durch das DIKJ erhoben. Die verschiedenen Diagnosegruppen wurden anhand der Kriterien der ICD-10 gebildet. Ergebnisse: Mit zunehmendem Alter zeigte sich ein Abfall des Serotiningehaltes im Thrombozyten. Die männlichen Patienten wiesen höhere Serotoninwerte im Vergleich zu den weiblichen auf, wobei die Mädchen allerdings höhere Depressivitätsscores im DIKJ zeigten. Es bestand eine negative Korrelation zwischen dem thrombozytären Serotonin und dem im DIKJ gemessenen Depressivitätsgrad über alle Diagnosegruppen. Unabhängig von der klinischen Diagnose ergaben sich signifikant niedrigere Serotoninkonzentrationen bei den Kindern und Jugendlichen, die unmittelbar vor der stationären Aufnahme einen Suizidversuch unternommen hatten. Auch bei der Gruppe der depressiven Störungen kristallisierte sich eine Untergruppe mit signifikant niedrigerem Serotoningehalt heraus, die kurz zuvor einen Suizidversuch verübt hatten. Schlussfolgerungen: Die vorliegenden Untersuchungen stützen die Auffassung, dass Depressivität in der Kindheit und Jugend mit einem Mangel an Serotonin im Thrombozyten bzw. analog zum Thrombozytenmodell in zentralen Strukturen verbunden ist und ein relatives Defizit an Serotonin ein Suizidalitätsmarker sein könnte.

Biochemical, behavioral, physiologic, and neurodevelopmental changes in mice deficient in monoamine oxidase A or B

The availability of mutant mice that lack either MAO A or MAO B has created unique profiles in the central and peripheral availability of serotonin, norepinephrine, dopamine, and phenylethylamine. This paper summarizes some of the current known phenotypic findings in MAO A knock-out mice and contrast these with those of MAO B knock-out mice. Differences are discussed in relation to the biochemical, behavioral, and physiologic changes investigated to date, as well as the role played by redundancy mechanisms, adaptational responses, and alterations in neurodevelopment.

Relationship between impulsivity and platelet serotonin content in adolescents

The relationship between impulsivity and serotonin function was explored in impulsive and non-depressed adolescents. Platelet serotonin content was chosen as a peripheral indicator of central serotonin function. Impulsivity was assessed with a questionnaire. All measures were performed once a week over a 6-week period for all subjects. Subjects comprised eight adolescent inpatients who were hospitalized as a result of their impulsive acts and eight healthy age- and sex-matched control subjects. Mean platelet serotonin concentration was significantly higher in the impulsive group than in the control group. Platelet serotonin concentration was positively correlated with the intensity of impulsivity in the patient group.

Ketanserin and tetrabenazine abolish aggression in mice lacking monoamine oxidase A

Mice deficient in monoamine oxidase A (MAO A) have elevated brain levels of 5-HT and manifest enhanced aggression. We used these mice as a model to study the role of 5-HT in aggression. Our results show that ketanserin and tetrabenazine (TBZ) strikingly abolished the aggressive behavior of MAO A-deficient mice. The anti-aggressive effect of ketanserin may be primarily mediated by 5-HT(2A) receptors. Another specific 5-HT(2A) antagonist, [R-(+)-a-(2, 3-dimethoxyphenyl)-1-[2-(4-fluorophenylethyl)]-4-piperidine-methan ol (MDL 100907), also blocks the aggression of mutant mice but was less dramatic. Ketanserin and TBZ are both antagonists of the vesicular monoamine transporter (VMAT2). The anti-aggressive effect of TBZ and part of the effect of ketanserin may be mediated by the VMAT2. Using radioligand binding and autoradiography, we also showed that the numbers of VMAT2, 5-HT(1A), 5-HT(2A) and 5-HT(2C) sites are decreased in brains of mutant mice, which may reflect down-regulation by excess 5-HT. This study suggests that ketanserin and TBZ may be developed as novel anti-aggressive agents.

Plasma monoamine metabolites and aggression: two studies of normal and oppositional defiant disorder children

In two studies the relationship between plasma monoamine metabolites and different parameters of aggression were examined in children suffering from severe aggression and antisocial behavior. No prior studies have related measures of serotonergic function to experimentally elicited aggression and only a few included healthy comparison groups. Plasma 5-HIAA, HVA and MHPG were measured in 15 boys with a oppositional defiant disorder (ODD) and 25 normal controls (NC) (study 1), and 22 ODD and 25 NC children (study 2). On a separate occasion each subject had the opportunity to behave aggressively towards an opponent. 5-HIAA and HVA were significantly lower in the ODD than NC group and both parameters were significantly inversely correlated with aggression and delinquency. These findings were replicated in the second study: The results of the study support a role for serotonergic functioning in persistent antisocial and aggressive behavior in young children.

Serotonergic functioning in depressed abused children: clinical and familial correlates

BACKGROUND

The goal of this study was to examine serotonergic functioning and concomitant clinical and familial correlates in depressed abused children.

METHODS

L-5-Hydroxytryptophan (L-5-HTP) (0.8 mg/kg) was administered intravenously to 10 depressed abused (MDD-AB), 10 depressed nonabused (MDD-NA), and 10 normal control nonabused (NC-NA) children. The children in the two nonabused cohorts represent a small matched subset of children from a larger interlocking study of the psychobiology of depression. Blood samples for prolactin and cortisol were collected from 30 min before to 2.5 hours after L-5-HTP infusion.

RESULTS

The MDD-AB children secreted significantly more prolactin post-L-5-HTP than the children in the other two groups. There were no differences in baseline prolactin or any of the cortisol measures. Total prolactin post-L-5-HTP was significantly correlated with clinical ratings of aggressive behavior (rho = .48). In addition, children with a family history positive for suicide attempt (MDD-AB: n = 7; MDD-NA: n = 5; NC-NA: n = 2) secreted significantly more prolactin post-L-5-HTP than children with no family history of suicide.

CONCLUSIONS

Dysregulation in the serotonergic system in abused children appears to be related to both familial and experiential factors.

Peripheral serotonin measures in prepubertal psychiatric inpatients and normal children: associations with suicidal behavior and its risk factors

BACKGROUND

This study reports relationships between suicidal behavior and its risk factors in prepubertal children and whole blood and platelet serotonin-related measures.

METHODS

Seventy-five prepubertal psychiatric inpatients including 23 (30.7%) nonsuicidal, 32 (42.7%) with suicidal ideation, and 20 (26.6%) with a suicide attempt were compared to 35 normal prepubertal controls with regard to platelet serotonin content, serotonin-amplified platelet aggregation, and whole blood tryptophan.

RESULTS

Mean whole blood tryptophan content was significantly lower among inpatient children with a recent suicide attempt than among normal controls or inpatients with suicidal ideation (F = 3.94, df = 3.54, p < or = .01). Inpatient children with a mood disorder had significantly higher platelet serotonin content than inpatients without a mood disorder (F = 3.86, df = 2.80, p < or = .03). Racial/ethnic differences were also observed for inpatients and normal controls, with whites having significantly lower levels of platelet serotonin (expressed as ng/mL blood or ng/10(9) platelets) than blacks or Latinos. Blacks had significantly higher levels of whole blood tryptophan than other racial/ethnic groups.

CONCLUSIONS

The results suggest that whole blood tryptophan and platelet serotonin content should be studied for their predictive validity as risk factors for suicidal behavior in youth while controlling for racial/ethnic differences.

Whole blood serotonin relates to violence in an epidemiological study

BACKGROUND

Clinical and animal studies suggest that brain serotonergic systems may regulate aggressive behavior; however, the serotonin/violence hypothesis has not been assessed at the epidemiological level. For study of an epidemiological sample we examined blood serotonin, because certain physiological and behavioral findings suggested that it might serve as an analog marker for serotonergic function.

METHODS

Whole blood serotonin was measured in a representative birth cohort of 781 21-year-old women (47%) and men (53%). Violence was measured using cumulative court conviction records and participants' self-reports. Potential intervening factors addressed were: gender, age, diurnal variation, diet, psychiatric medications, illicit drug history, season of phlebotomy, plasma tryptophan, platelet count, body mass, suicide attempts, psychiatric diagnoses, alcohol, tobacco, socioeconomic status, IQ, and overall criminal offending.

RESULTS

Whole blood serotonin related to violence among men but not women. Violent men's mean blood serotonin level was 0.48 SD above the male population norm and 0.56 SD above the mean of nonviolent men. The finding was specific to violence, as opposed to general crime, and it was robust across two different methods of measuring violence. Together, the intervening variables accounted for 25% of the relation between blood serotonin and violence.

CONCLUSIONS

To our knowledge, this is the first demonstration that an index of serotonergic function is related to violence in the general population.

Platelet serotonin measures in adolescents with conduct disorder

Dysregulation of serotonergic function has been associated with aggression in several studies involving children, adolescents, and adults. This study investigated the relationship of platelet serotonergic measures to conduct disorder type, severity of aggression, and social skills impairment. Standardized assessments of diagnosis, aggression, impulsivity, and social skills were obtained from 43 male adolescents (ages 13-17) incarcerated at an involuntary residential treatment facility for juvenile offenders. Blood samples were collected and assayed for whole blood serotonin (5-HT) and platelet [3H]-paroxetine-labeled 5-HT-transporter binding. Whole blood 5-HT was higher in adolescents with conduct disorder, childhood type than in subjects with conduct disorder, adolescent type. Whole blood 5-HT was positively correlated with violence rating of the current offense and total offense points, and staff ratings of social skills impairment. Our findings are consistent with a relationship between 5-HT dysregulation and aggressive behavior in incarcerated adolescent boys with conduct disorder, particularly of childhood onset.

Practice parameters for the assessment and treatment of children and adolescents with conduct disorder. American Academy of Child and Adolescent Psychiatry

These practice parameters address the diagnosis, treatment, and prevention of conduct disorder in children and adolescents. Voluminous literature addresses the problem from a developmental, epidemiological, and criminological perspective. Properly designed treatment outcome studies of modern psychiatric modalities are rare. Ethnic issues are mentioned but not fully addressed from a clinical perspective. Clinical features of youth with conduct disorder include predominance in males, low socioeconomic status, and familial aggregation. Important continuities to oppositional defiant disorder and antisocial personality disorder have been documented. Extensive comorbidity, especially with other externalizing disorders, depression, and substance abuse, has been documented and has significance for prognosis. Clinically significant subtypes exist according to age of onset, overt or covert conduct problems, and levels of restraint exhibited under stress. To be effective, treatment must be multimodal, address multiple foci, and continue over extensive periods of time. Early treatment and prevention seem to be more effective than later intervention.

Whole-blood serotonin in children and adolescents with mood and behavior disorders

Whole-blood serotonin (5-hydroxytryptamine, 5-HT) levels were measured in 118 children and adolescents with DSM-III-R mood disorders (n = 30) or behavior disorders (n = 27), a mixed group who met criteria for both mood and behavior disorders (n = 47), and a small sample of normal control subjects (n = 14). The patients were selected from consecutive admissions to an inpatient state hospital setting and the control subjects were recruited from a local high school. Levels of whole-blood 5-HT were significantly higher in the behavior disorder group (193 +/- 120) than in the mood disorder (122 +/- 83) or mixed mood and behavior (137 +/- 95) patient groups, but did not differ from control levels (170 +/- 48). A subsample of patients irrespective of diagnostic classification who had been on a selective serotonin reuptake inhibitor (SSRI) before admission had significantly lower whole-blood 5-HT concentrations (97.8 +/- 78.4) than those in patients who had been receiving some other type of psychotropic medication at admission (159.8 +/- 109.2) and from those in unmedicated patients (161.9 +/- 101.4). The 5-HT concentrations for patients receiving non-SSRI psychotropic medications did not differ from those of unmedicated patients. The frequency analysis of 5-HT concentration by psychiatric disorder group suggests that patients with mood disorders have the lowest values (below 100 ng/ml) and patients with behavior disorders have the highest values (above 300 ng/ml). Levels in the limited sample of normal subjects were all between 100 and 300 ng/ml. These findings were not accounted for by age, sex, gender, race, or season and lend support to accumulating research on simple neurobiological indicators in blood that help to distinguish these child/adolescent psychiatric disorders from each other and from individuals without these disorders.

Abnormality of EEG alpha asymmetry in female adolescent suicide attempters

Abnormal electroencephalographic (EEG) activity has been associated with various psychiatric disorders and behaviors, including depression, suicide, and aggression. We examined quantitative resting EEG in Hispanic female adolescent suicide attempters and matched normal controls. Computerized EEG measures were recorded at 11 scalp sites during eyes open and eyes closed periods from 16 suicide attempters and 22 normal controls. Suicide attempters differed from normal controls in alpha asymmetry. Normal adolescents had greater alpha (less activation) over right than left hemisphere, whereas suicidal adolescents had a nonsignificant asymmetry in the opposite direction. Nondepressed attempters were distinguished from depressed attempters in that they accounted for the preponderance of abnormal asymmetry, particularly in posterior regions. Alpha asymmetry over posterior regions was related to ratings of suicidal intent, but not depression severity. The alpha asymmetry in suicidal adolescents resembled that seen for depressed adults in its abnormal direction, but not in its regional distribution. Findings for suicidal adolescents are discussed in terms of a hypothesis of reduced left posterior activation, which is not related to depression but to suicidal or aggressive behavior.

Polygenic inheritance of Tourette syndrome, stuttering, attention deficit hyperactivity, conduct, and oppositional defiant disorder: the additive and subtractive effect of the three dopaminergic genes--DRD2, D beta H, and DAT1

Polymorphisms of three different dopaminergic genes, dopamine D2 receptor (DRD2), dopamine beta-hydroxylase (D beta H), and dopamine transporter (DAT1), were examined in Tourette syndrome (TS) probands, their relatives, and controls. Each gene individually showed a significant correlation with various behavioral variables in these subjects. The additive and substractive effects of the three genes were examined by genotyping all three genes in the same set of subjects. For 9 of 20 TS associated comorbid behaviors there was a significant linear association between the degree of loading for markers of three genes and the mean behavior scores. The behavior variables showing the significant associations were, in order attention deficit hyperactivity disorder (ADHD), stuttering oppositional defiant, tics, conduct, obsessive-compulsive, mania, alcohol abuse and general anxiety-behaviors that constitute the most overt clinical aspects of TS. For 16 of the 20 behavior scores there was a linear progressive decrease in the mean score with progressively lesser loading for the three gene markers. These results suggest that TS, ADHD, stuttering oppositional defiant and conduct disorder, and other behaviors associated with TS, are polygenic, due in part to these three dopaminergic genes, and that the genetics of other polygenic psychiatric disorders may be deciphered using this technique.

Attention deficit hyperactivity disorder and whole-blood serotonin levels: effects of comorbidity

Whole-blood serotonin (5-hydroxytryptamine, 5-HT) levels were measured in children with attention deficit hyperactivity disorder (ADHD) with and without comorbid conduct disorder (CD) or oppositional-defiant disorder (ODD). It was hypothesized that the whole-blood 5-HT levels of ADHD probands would be significantly correlated with the whole-blood 5-HT levels of their mothers. Fifty-two children who met DSM-III-R criteria for ADHD were selected consecutively from an ADHD clinic (47 males--35 Caucasians, 10 African-Americans, and 2 Hispanics; 10 females--all Caucasians). Whole-blood 5-HT was assayed by high performance liquid chromatography and compared between ADHD children with and without comorbid CD or ODD. The familiality of whole-blood 5-HT levels was studied by Spearman's rank-order correlation. There were no significant age, race, or sex effects. There was no significant difference in whole-blood 5-HT levels between children with ADHD only (n = 22; 190 +/- 45 ng/ml) and ADHD with CD or ODD (n = 30; 212 +/- 67). However, 7 out of 30 (23%) children with ADHD+CD/ODD had whole-blood 5-HT levels > 270 ng/ml, while none of the ADHD-only children had whole-blood 5-HT levels > 270 ng/ml, a statistically significant difference. Whole-blood 5-HT levels showed significant positive correlations between 36 children with disruptive behavior disorders and their biological mothers (rs = 0.47). There was no difference in mean levels of whole-blood 5-HT between subgroups of children with ADHD with or without comorbid CD or ODD.(ABSTRACT TRUNCATED AT 250 WORDS)

Whole blood serotonin and disruptive behaviors in juvenile obsessive-compulsive disorder

OBJECTIVE

The study was conducted with children and adolescents with obsessive-compulsive disorder (OCD) to assess the relationship of whole blood serotonin (5-HT) content to a concurrent diagnosis of a disruptive behavior disorder (DBD) and to severity ratings of aggressive behavior.

METHOD

Eighteen children and adolescents who met DSM-III-R criteria for OCD were evaluated with a structured interview, clinician rating scales, and the Child Behavior Checklist (CBCL). Blood 5-HT concentration was assayed with a fluorometric procedure. Relationships among categorical diagnoses, dimensional ratings, and blood 5-HT content were analyzed with bivariate and multivariate techniques.

RESULTS

OCD subjects with a DBD (n = 6) had significantly higher scores than those without a DBD (n = 12) on the Total Problem scale, the Externalizing Problem scale, and several of the behavioral syndrome scales of the CBCL. Blood 5-HT concentrations were significantly lower in those with a DBD than in those without a DBD, and blood 5-HT concentrations had significant negative correlations with the Total score, the Externalizing score, and the Aggressive Behavior score of the CBCL.

CONCLUSIONS

The results provide further evidence of a significant relationship between aggressive behavior and serotonergic functioning.

Correlates of violence risk in hospitalized adolescents

Forty adolescent inpatients with histories of frequent interpersonal violent behavior were compared with 36 hospitalized adolescents without histories of overt violence using self-report questionnaires that measured violence risk, depression, impulsivity, and suicide risk. The two groups did not differ in terms of their demographic characteristics, but the violent patients had a higher prevalence of substance abuse and borderline personality disorder diagnoses. Violent adolescents were more impulsive and at higher suicide risk than nonviolent adolescents. In addition, violent adolescents had more positive histories of suicide attempts and had significantly higher family histories of attempted and completed suicide. In the total sample of adolescents, violence risk was significantly correlated with impulsivity and suicide risk, but not with depression.

Dopamine-beta-hydroxylase in behaviorally disturbed youth. Relationship between teacher and parent ratings

A series of neurotransmitters, metabolites, and enzymes considered relevant to emotional and behavioral disorders was studied in blood samples obtained from boys admitted to a residential setting because of disruptive or unmanageable behavior in their home environments. The youth were categorized into mainly prepubertal (under 12.0 years) and pubertal/post pubertal (12.0 years and over) groups. Behavior ratings of the younger group completed by parents revealed significant inverse correlations between several behavioral factors and dopamine-beta-hydroxylase (DBH) activity levels, notably in the aggressive behavior and antisocial domains. Teacher ratings completed after about 1 month of living in the residential setting also showed numerous significant, but positive, correlations between several behavior factors and DBH activity levels. Furthermore, teacher and parent ratings themselves often were significantly and inversely correlated. The findings related to DBH activity levels were strongest in the younger group of boys. The results are discussed in terms of the possibility that low DBH activity in boys reflects a vulnerability towards behavioral disorder, which in certain environments becomes manifested by conduct problems and antisocial behavior.

Biodevelopmental aspects of conduct disorder in boys

The association between biochemical parameters and conduct disorder (CD) was studied in 22 boys admitted to a residential center. Three-methoxy-4-hydroxyphenylglycol (MHPG) levels were significantly higher in prepubertal CD youth than in pubertal/post pubertal CD youth. Homovanillic acid (HVA) levels were significantly lower in CD youth under age 12.0 years than in non CD youth under age 12.0 years. The implications of these biodevelopmental findings in the study of CD are discussed.

Platelet and whole blood serotonin content in depressed inpatients: correlations with acute and life-time psychopathology

Platelet or whole blood serotonin content did not differ significantly in patients with major depression compared to healthy controls, but within the patient group, platelet serotonin levels correlated negatively with severity of depression (r = -0.49, p = 0.007). Levels were 39% lower in patients who had made a suicide attempt compared to nonattempter patients (47.2 +/- 27.3 versus 77.6 +/- 41.7 ng/10(8) platelets, p = 0.04). Conversely, comorbid borderline personality disorder (85.3 +/- 41.5 ng/10(8) platelets) was associated with 31% greater platelet serotonin content than nonborderline patients (58.9 +/- 31.1 ng/10(8) platelets) and 27% greater than healthy controls (62.4 +/- 19.8 ng/10(8) platelets). A pronounced seasonal variation in whole blood and platelet serotonin content was found in both patients and controls, largely due to lower levels in summer. Excluding cases tested in the summer abolished the statistically significant differences in patients with and without comorbid borderline personality disorder (BPD). Nevertheless, BPD attempters had lower serotonin levels than BPD nonattempters but higher serotonin levels than non-BPD attempters. Current hostility and a life-time history of aggression were positively correlated with platelet serotonin content (r = 0.44, p = 0.04 and r = 0.41, p = 0.06). This study provides evidence for an association between lower platelet serotonin content and depression and suicidal behavior, and association of higher platelet serotonin content and comorbid borderline personality disorder and behavior traits such as aggressivity.

Low dopamine-beta-hydroxylase: a biological sequela of abuse and neglect?

Twenty-one psychiatrically hospitalized boys were studied while off psychoactive medication to determine if conduct disorder, solitary type, and abuse or neglect experiences correlated with low levels of dopamine-beta-hydroxylase (DBH) activity. Preliminary results supported earlier findings that undersocialized types of conduct disorder in boys were correlated with low DBH activity. Possible or definite neglect or abuse before 36 months of age was correlated with low DBH activity. Abuse or neglect was not correlated with low DBH activity when time of occurrence was not specified. Low serum DBH may be a biological sequela of seriously disrupted attachment.

Anxiety, inhibition, and conduct disorder in children: II. Relation to salivary cortisol

The relation of symptoms of conduct disorder (CD) and anxiety to salivary cortisol was explored in 67 clinic-referred boys aged 8 to 13 years. Children with anxiety disorder had higher levels of cortisol, but this main effect was qualified by a significant CD x anxiety disorder interaction. Consistent with Gray's biological model of the behavioral inhibition system (BIS), children with both CD and anxiety disorder had higher levels of salivary cortisol than children with CD without comorbid anxiety disorder. In the absence of CD, however, anxiety disorder was not clearly associated with higher cortisol. This result suggests that cortisol may be a useful biological marker of arousal associated with BIS activity in children with CD.

Serotoninergic findings in habitual violence and impulsivity. A review

Several lines of evidence suggest that there may be abnormal brain serotonin metabolism in habitually biolent and impulsive offenders. These personality disorders are usually connected with early onset, male limited type 2 alcoholism in which one central feature is the abnormal tendency to behave aggressively and impulsively under the influence of alcohol repeatedly. Low CSF 5-HIAA has been found to correlate with familial alcoholism tendencies; paternal alcoholism. Both this and with it the tendency to abnormal oral glucose tolerance test (tendency to low blood glucose nadir) predict the new violent and impulsive crimes under the influence of alcohol. Also peripheral measures such as platelet MAO, abnormal tryptophan/LNAA ratio in plasma, whole blood serotonin, blood platelet uptake of serotonin, platelet 3H-IMI dinging (Bmax), abnormal prolactin and Cortisol secretion in fenfluramine challenge, and possibly daily urinary free Cortisol secretion correlate with impulsive aggressive behavior.