Predictors of valproic acid steady-state serum levels in adult and pediatric psychiatric inpatients: a comparative analysis

RATIONALE

Valproic acid (VPA) is commonly used as a second-line mood stabilizer or augmentative agent in severe mental illnesses. However, population pharmacokinetic studies specific to psychiatric populations are limited, and clinical predictors for the precision application of VPA remain undefined.

OBJECTIVES

To identify steady-state serum VPA level predictors in pediatric/adolescent and adult psychiatric inpatients.

METHODS

We analyzed data from 634 patients and 1,068 steady-state therapeutic drug monitoring (TDM) data points recorded from 2015 to 2021. Steady-state VPA levels were obtained after tapering during each hospitalization episode. Electronic patient records were screened for routine clinical parameters and co-medication. Generalized additive mixed models were employed to identify independent predictors.

RESULTS

Most TDM episodes involved patients with psychotic disorders, including schizophrenia (29.2%) and schizoaffective disorder (17.3%). Polypharmacy was common, with the most frequent combinations being VPA + quetiapine and VPA + promethazine. Age was significantly associated with VPA levels, with pediatric/adolescent patients (< 18 years) demonstrating higher dose-adjusted serum levels of VPA (β = 7.6±2.34, p < 0.001) after accounting for BMI. Women tended to have higher adjusted VPA serum levels than men (β = 5.08±1.62, p < 0.001). The formulation of VPA (Immediate-release vs. extended-release) showed no association with VPA levels. Co-administration of diazepam exhibited a dose-dependent decrease in VPA levels (F = 15.7, p < 0.001), suggesting a potential pharmacokinetic interaction.

CONCLUSIONS

This study highlights the utility of population-specific pharmacokinetic data for VPA in psychiatric populations. Age, gender, and co-administration of diazepam were identified as predictors of VPA levels. Further research is warranted to establish additional predictors and optimize the precision application of VPA in psychiatric patients.

Association between neutrophil to lymphocyte ratio and mood polarity in adolescents admitted to an inpatient psychiatric ward

Inflammatory processes are associated with mood disorders, but data on pediatric patients are scarce. The aim of this study was to investigate a possible association between elevated neutrophil/lymphocyte ratio (NLR) - a marker of inflammation and mood polarity (manic/depressed) in adolescents, admitted between 2010 and 2015 due to a mood disorder episode and to an adolescent inpatient ward. Electronic medical records of 305 patients (aged 10-19 years, 60.6% males) admitted during the study period due to a mood disorder episode were reviewed. Of these, 63 were diagnosed with manic episodes and 242 with depressive episodes. Multivariate analyses were used to compare NLR between and within the two groups, covarying for age, sex, and antipsychotic use. NLR was significantly higher in the manic episode group compared with the depression one. Moreover, in inpatients with multiple hospitalizations, the NLR was higher during their manic episodes than that during their nonmanic states. These results suggest that, as has been reported in adults with bipolar disorder, inflammatory mechanisms may be involved in adolescents' mood disorders as well, particularly in the manic episodes. Thus, clinicians may consider adding anti-inflammatories as part of the treatment of these patients.

Brain Motor Region Diffusion Tensor Imaging in Patients with Catatonic Schizophrenia: A Case-Control Study

BACKGROUND

Only a small proportion of schizophrenia patients present with catatonic symptoms. Imaging studies suggest that brain motor circuits are involved in the underlying pathology of catatonia. However, data about diffusivity dysregulation of these circuits in catatonic schizophrenia are scarce.

OBJECTIVES

To assess the involvement of brain motor circuits in schizophrenia patients with catatonia.

METHODS

Diffusion tensor imaging (DTI) was used to measure white matter signals in selected brain regions linked to motor circuits. Relevant DTI data of seven catatonic schizophrenia patients were compared to those of seven non-catatonic schizophrenia patients, matched for sex, age, and education level.

RESULTS

Significantly elevated fractional anisotropy values were found in the splenium of the corpus callosum, the right peduncle of the cerebellum, and the right internal capsule of the schizophrenia patients with catatonia compared to those without catatonia. This finding showed altered diffusivity in selected motor-related brain areas.

CONCLUSIONS

Catatonic schizophrenia is associated with dysregulation of the connectivity in specific motoric brain regions and corresponding circuits. Future DTI studies are needed to address the neural correlates of motor abnormalities in schizophrenia-related catatonia during the acute and remitted state of the illness to identify the specific pathophysiology of this disorder.

Body mass index increase in preschoolers with heterogeneous psychiatric diagnoses treated with risperidone

OBJECTIVE

Use of risperidone in preschool-aged children is growing, with rising concerns of adverse metabolic consequences. Longitudinal data on risperidone-related weight gain in preschoolers are scarce. We aimed to evaluate changes in body mass index (BMI) that are associated with risperidone treatment in preschoolers.

METHOD

We analyzed naturalistic, longitudinal data on 141 preschool children (112 boys, 29 girls) receiving psychiatric care. Mean patient age at baseline was 5.0 years (SD=0.8) and average follow-up period was 1.3 years (SD=0.8), with >8 mean BMI measurements per patient. We studied the effect of risperidone exposure (n=78) on age-and-sex-standardized BMI (BMI Z-score) implementing mixed models with random subject intercepts to account for repeated measures, covarying for multiple confounders including demographics, stimulant treatment and psychiatric diagnoses. We employed similar models to study dose and duration effects.

RESULTS

Risperidone treatment was significantly associated with an increase in BMI (effect size of exposure=0.45 SD (SE=0.06), t (949)=7.7, p<0.001) covarying for stimulant exposure and other confounders, independent of treatment indication. Females exhibited stronger effects (risperidone treatment × sex interaction t=2.32, p=0.02)). Risperidone daily dose was associated with increase in BMI (for each additional 1 mg, effect size=0.28 SD (SE=0.07), t(419)=3.76, p<0.001).

CONCLUSION

Similar to older populations, risperidone treatment in preschoolers is associated with significant weight gain, with evidence for dose effects. Findings provide critical data that can inform clinicians.

Elevated neutrophil to lymphocyte ratio in non-affective psychotic adolescent inpatients: Evidence for early association between inflammation and psychosis

Accumulating data suggest an association between inflammation and schizophrenia and related psychosis. While several studies have established this immune-psychosis association in adult schizophrenia patients, there is very limited data associating inflammation with acute psychosis in children and adolescents. The ratio between neutrophils and lymphocyte, computed from routine blood counts, has been shown to correlate with traditional markers of inflammation, and is therefore considered a proxy-marker for inflammation. Here we report elevated neutrophil to lymphocyte ratio and total leukocyte count in psychotic adolescent inpatients (n = 81, mean age 14.7 years, 52% males) compared to non-psychotic adolescent inpatient (n = 285, mean age 15.9 years, 58% males), in a population of adolescent inpatients with no affective symptomatology. The elevated neutrophil to lymphocyte ratio remained significant after controlling for confounders such as age, BMI, smoking and antipsychotic medication. In a subset of psychotic adolescent inpatients (n = 20, mean duration between blood test 157 days), we found significant decrease in neutrophil to lymphocyte ratio at clinical remission compared with the acute psychotic state. The results suggest that psychosis is associated with peripheral markers of inflammation early in the course of psychiatric pathology, and that inflammation may represent a state that accompanies psychosis and decreases during clinical remission.

Serum Ferritin Levels Are Lower in Children With Tic Disorders Compared with Children Without Tics: A Cross-Sectional Study

OBJECTIVES

Alteration in peripheral iron indices has been reported in a number of movement disorders, particularly Parkinson's disease. We hypothesized that iron stores may be diminished in children at an early stage of tic disorder.

METHODS

Using data retrieved from electronic medical records, we compared serum ferritin levels, an indicator of body iron store balance, in drug-naive children diagnosed for the first time with tic disorder (study group; N = 47, 32 boys/15 girls, aged 8.66 ± 3.17 years) compared to age- and sex-matched children with headaches (comparison group, n = 100, 62 boys/38 girls, aged 9.51 ± 3.15 years) treated in the same pediatric neurological clinic.

RESULTS

Mean serum ferritin levels were significantly lower (-32%, p = 0.01) in the tic disorder group compared to the headache group. No significant differences were detected in circulatory hemoglobin, iron, transferrin, and platelet count between the two groups.

CONCLUSION

Our findings suggest that body iron stores may be reduced in children with recent-onset tic disorder.

THE MERCURY-SENSITIZED PRIMARY DECOMPOSITION OF DEUTERATED PROPANES: A MASS SPECTROMETRIC STUDY AT LOW PRESSURES: PART II

The primary decomposition of C3H8, CD3CH2CD3, CH3CD2CH3, and C3D8 was found equal to: 10, 8, 5.5, and 5%.The primary reactions were[Formula: see text]The ratio a/b was strongly affected by deuterium substitution. The numerical values of the ratio for the compounds in the order given above are: 1.2, 6.8, 0.2, 0.9. Elucidation of the underlying reasons for this surprisingly large isotope effect might throw new light on the excited mercury – paraffin interaction.

THE MERCURY-PHOTOSENSITIZED DECOMPOSITION OF PROPANE: A MASS SPECTROMETRIC STUDY AT LOW PRESSURES: PART I

It is found that the primary decomposition involves the cleavage of a C—H bond. Both primary and secondary hydrogen atoms are lost. The relative rates of the two processes could not be determined accurately but are estimated to be approximately 1:1. It is found that at least 70% of the secondary reactions involves the interaction of hydrogen atom with a propyl radical. The main reaction is the re-formation of propane. An important disproportionation of hydrogen atoms with propyl radicals leading to propylene is shown to occur. The atomic cracking reaction H + C3H7 → C3H8* → C2H5 + CH3 is also observed. Using mixtures of C3H8 and C3D8 the relative cracking rate of n-propyl- to isopropyl-derived propane is determined to be equal to 5. This result is compared with theoretical predictions.

HYDROGEN ATOM RECOMBINATION IN THE FLOW SYSTEM ATTACHED TO A MASS SPECTROMETER AND USED FOR THE STUDY OF MERCURY-SENSITIZED REACTIONS

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