Comparison of whole blood serotonin and platelet MAO in children with schizophrenia and major depressive disorder

Altered affinity of the platelet vesicular monoamine transporter 2 to dihydrotetrabenazine in children with major depression

Platelet vesicular monoamine transporter (VMAT2) binding characteristics were assessed, using high affinity dihydrotetrabenazine ([(3)H]TBZOH) binding, in 14 children with major depression (MDD) and 16 matched controls. All participants underwent a thorough diagnostic evaluation and the levels of depression and anxiety were measured. K (d) values were significantly lower in children with MDD versus controls (2.93 ± 0.84 vs. 3.63 ± 0.56 nM, respectively, t = 2.4, df = 18.4, p = 0.025). B (max) values did not differ significantly. This preliminary finding indicates a possible structural change in platelet VMAT2 in children with MDD.

Decreased blood serotonin in the premenstrual phase enhances negative mood in healthy women

The purpose of this study was to evaluate mechanisms underlying the action of selective serotonin reuptake inhibitors on the improvement of negative mood symptoms in premenstrual syndrome. We assessed relationships between serotonin (5-HT) levels in the brain (estimated from 5-HT concentrations in whole blood) and negative mood states during the premenstrual phase in 13 healthy women. Mood states were evaluated using the Profile of Mood States questionnaire. We also evaluated relationships between 5-HT and ovarian hormones (oestradiol and progesterone). A significant negative correlation was seen between 5-HT concentrations in whole blood and negative mood scores (tension-anxiety and fatigue) observed in the premenstrual phase. A significant positive correlation was observed between 5-HT and oestradiol in the premenstrual phase, but not in the follicular phase. These results suggest that healthy women with lower whole blood 5-HT concentrations in the premenstrual phase exhibit enhanced negative mood due to lower 5-HT concentrations at brain synapses, which may be caused in part by lower oestrogen concentration.

Depression and whole blood serotonin in patients with coronary heart disease from the Heart and Soul Study

OBJECTIVE

To evaluate whether depression is associated with whole blood serotonin in outpatients with stable coronary heart disease (CHD). Depression is associated with incident CHD and with adverse cardiovascular outcomes. Dysregulation of peripheral serotonin, common to both depression and CHD, may contribute to this association.

METHODS

We performed a cross-sectional study of 791 participants with stable CHD enrolled in the Heart and Soul Study and not taking antidepressant medication. We assessed major depression using the Computerized Diagnostic Interview Schedule (CDIS-IV) and measured whole blood serotonin (WBS) from fasting venous samples.

RESULTS

Of the 791 participants, 114 (14%) had current (past month) major depression, 186 (24%) had past (but not current) major depression, and 491 (62%) had no history of depression. Age-adjusted mean WBS was higher in participants with current major depression (139 +/- 6.5 ng/ml) than in those with past depression (120 +/- 5.0 ng/ml) or no history of depression (119 +/- 3.1 ng/ml) (p = .02). This association was unchanged after adjustment for demographic characteristics, medical comorbidities, medication use, and cardiac disease severity (p = .02). When serotonin was analyzed as a dichotomous variable, current depression was associated with a 70% greater odds of having WBS in the highest quartile (adjusted odds ratio = 1.71; 95% Confidence Interval = 1.03-2.83; p = .04).

CONCLUSIONS

In this sample of patients with stable CHD, current major depression was independently associated with higher mean WBS levels. Future studies should examine whether elevated WBS may contribute to adverse outcomes in patients with depression and CHD.

Neurobiology of depression in children and adolescents

This article reviews classical and updated studies of the neurobiology of depressive disorders in children and adolescents. Most studies of childhood and adolescent depression and suicide have followed up the observations and methods used in studies in adults. These studies include neuroendocrine studies, which particularly look at the hypothalamic-pituitary-adrenal axis, the serotonergic system, peripheral blood and cerebrospinal fluid biologic markers, genetics, gene-environment interactions and sleep studies, and neuroimaging and postmortem studies, although in these areas the number of studies is limited.

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.

Platelet monoamine oxidase in healthy 9- and 15-years old children: the effect of gender, smoking and puberty

1. The effect of gender, smoking and pubertal development on platelet monoamine oxidase (MAO) activity was described in a randomly selected, large sample of 9- and 15-years old healthy children. 2. Platelet MAO activity was measured in 1129 children by a radioenzymatic method with beta-phenylethylamine as the substrate. Smoking habits were reported in an anonymous questionnaire. Pubertal status was assessed visually using Tanner's stages. 3. Boys, younger children and smokers had significantly lower platelet MAO activity than girls, older children and non-smokers, respectively. Girls in Tanner's stage V for breast and pubic hair development had significantly lower MAO than girls in stage IV. 4. Differences in gender, age, pubertal status and smoking habits must be taken into account if the relationship between platelet MAO activity, personality and psychiatric disorders is studied in children.

Social skills deficits in schizotypal personality disorder

Evidence of long-standing social difficulties has been well documented in persons with schizophrenia. These deficits are often so rudimentary that a person with schizophrenia may never have developed the skills necessary to present as socially competent. Given the cognitive, biological, and neuroanatomical links between schizophrenia and schizotypal personality disorder (SPD), a study of social skills in persons with SPD may reveal a behavioral link. This study examined persons with SPD and their ability to label emotions in a recognition task, to display socially competent behaviors in a social role-play task, and to select appropriate behaviors from a multiple choice measure of social behavior. Results indicated that the performance of persons with SPD was similar to previously published findings in persons with schizophrenia. In terms of emotion recognition, the SPD group's ability to label positive emotions was significantly worse than their ability to label other emotions. Persons with SPD performed significantly worse than matched control participants on a social role-play task. However, the groups were equivalent in their ability to select socially appropriate behavior from a multiple choice measure. These results suggest that persons with SPD display social skills which mirror those previously reported in persons with schizophrenia.

Pediatric depression and psychopharmacology

Children can and do have depression which is similar to and continuous with that in adults. It can be diagnosed and treated similarly. Clinical evaluation reveals depression and laboratory tests are not required. It may be comorbid with other psychiatric or physical disorders. It causes considerable distress and impairment and suicide can be one serious sequel. Relapse or recurrences can occur. Etiology of depression is uncertain though hypotheses of psychogenesis or biogenesis exists. Psycho-pharmacological advances have helped in understanding etiology of depression and also in its effective treatment. So far, fluoxetine in the only antidepressant shown to be effective though others are also used. Antidepressants need to be given for one year or more.

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.

Mood correlates with blood serotonin, but not with glucose measures in patients with recurrent suicidal behavior

Depressive mood and impulsive-aggressive behavior are relevant to suicidal behavior and have been associated with decreased central serotonergic function. Impulsive behavior and aggression have also been related to abnormal glucose metabolism. To investigate these relationships further, blood serotonin (5-HT), blood glucose measures (glycated hemoglobin (HbA1C) and fructosamine) and self-reported depressive symptoms and anger were repeatedly measured, during a 1-year follow-up, in 106 patients who had recently attempted suicide for at least a second time. A major DSM-III-R Axis I diagnosis or use of antidepressants were reasons for exclusion. Intra-individual variations in blood 5-HT were inversely correlated with variations in depressive mood, self-depreciation, and anger, and positively with variations in fructosamine. Intra-individual variations of HbA1c or fructosamine were not correlated with mood. Mean blood 5-HT levels per patient were positively correlated with mean scores of depression and self-depreciation. The contrast between the intra-individual and the inter-individual correlations may reflect a difference between short- vs. long-term effects. The results do support an association between serotonergic function and mood, but not between glucose metabolism and mood, in recurrent suicide attempters.

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.

Platelet monoamine oxidase in schizophrenia: a meta-analysis

We did a meta-analysis on all publications (English and other languages) concerned with platelet monoamine oxidase (MAO) in schizophrenia. Essentially, when patients were medicated with a neuroleptic, most studies found that schizophrenics had lower platelet MAO levels than controls. Administration of neuroleptic lowers MAO levels. MAO levels in drug-free schizophrenics were similar to controls. Only a minority of studies found drug-free schizophrenics had decreased platelet MAO levels.

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.

Borderline disorders of childhood: an overview

This selected review considers children classified as "borderline" and focuses on two broad categories: Borderline personality disorder/borderline spectrum and schizotypal personality disorder/autism/schizophrenia spectrum classifications. Clinical descriptions, biological correlated, delimitation from other disorders, outcome, family studies, hypothesized etiologies, therapeutic considerations, and response to treatment are presented for each. Data support the subclassification of the heterogeneous groupings of borderline children into at least the two categories, and their differentiation from each other and from other clinical disorders in the population. Overlap across the borderline categories exists for individual children. The nature and shortcomings of relevant studies are described, the need for scientifically based research championed, and a differential approach to directive treatment of borderline children advocated. Further subclassification of borderline disorders should result in more cost-effective diagnosis and treatment.

Elevated platelet MAO is related to impulsivity in disruptive behavior disorders

Platelet monoamine oxidase (MAO) activity was measured in 32 drug-free prepubertal boys with externalizing symptoms of disruptive behavior disorders and 47 boys with no DSM-III-R diagnoses, and correlated to questionnaire and laboratory performance measures of impulsivity. A subgroup of boys with high MAO activity exhibited significantly poorer performance (i.e., more impulsivity) than a subgroup of low MAO activity on laboratory tasks requiring response inhibition. High MAO patients were more impulsive than high MAO controls on some performance tasks and elevated platelet MAO was unrelated to personality questionnaire measures of impulsivity or to patient status. These data suggest that biological markers such as MAO activity may correlate better with performance than clinical questionnaire measures. Abnormally high platelet MAO activity may not be sufficient to produce externalizing symptoms in children, perhaps interacting with an underlying behavioral dimension of impulsivity.

Increased serotonin2 (5-HT2) receptor binding as measured by 3H-lysergic acid diethylamide (3H-LSD) in the blood platelets of depressed patients

3H-Lysergic acid diethylamide (3H-LSD) binding, a putative measure of 5-HT2 receptor binding, was studied in the blood platelets of 29 depressed patients and 24 normal controls. The Bmax (maximum number of 3H-LSD binding sites) in the blood platelets of depressed patients was significantly greater than that of normal volunteers. This increase in Bmax was due to an increase in female depressed patients only. Bmax was significantly lower in female compared to male normal controls but there was no difference between male and female depressed patients. There was also no difference in Kd (an inverse measure of affinity of 3H-LSD binding to its sites) between normal controls and depressed patients. The correlations between Bmax of 3H-LSD binding and the Bmax of the 3H-imipramine binding site or the Vmax of 5-HT uptake sites were not significant. The role of serotonergic processes in the psychobiology of depression is discussed.

Blood serotonin levels in adults, autistic and non-autistic children--with a comparison of different methodologies

Recent interest in conditions associated with increased blood serotonin level has highlighted the need for consistency between assay methods to allow for more accurate delineation of serotonin variables. To this end, comparison was made between a spectrofluorimetric technique frequently used in the past and two potentially more specific high performance liquid chromatographic procedures. Normal ranges and diurnal variations for blood serotonin in adults, normal, autistic children and children with developmental dysphasia were also determined. No significant difference was found between serotonin level in blood drawn by simultaneous venepuncture and capillary (fingerprick) collection. Whilst there was no evidence of circadian rhythm, seasonal variation with mean blood serotonin levels significantly lower in summer than in two successive winters was suggested. Blood serotonin values in normal children tended to decline with increasing age. No similar maturational effect was apparent in autistic children. The mean level for autistic children in winter was significantly higher than that for normal children in the same season; despite this there was considerable overlap of blood serotonin levels between normal and autistic groups. Serotonin levels determined by the three different methodologies showed a high correlation but differed significantly: caution should be exercised when comparing blood serotonin results where different methods are employed.