Possible mechanisms for the skeletal effects of antipsychotics in children and adolescents

16S rRNA gene sequencing reveals altered gut microbiota in young adults with schizophrenia and prominent negative symptoms

BACKGROUND

Gut dysbiosis has been established as a characteristic of schizophrenia (SCH). However, the signatures regarding SCH patients with prominent negative symptoms (SCH-N) in young adults have been poorly elucidated.

METHODS

Stool samples were obtained from 30 young adults with SCH-N, 32 SCH patients with prominent positive symptoms (SCH-P) along with 36 healthy controls (HCs). Microbial diversity and composition were analyzed by 16S rRNA gene sequencing. Meanwhile, psychiatric symptoms were assessed by the positive and negative syndrome scale (PANSS).

RESULTS

There is a significant difference in β-diversity but not α-diversity indexes among the three groups. Moreover, we found a higher abundance of Fusobacteria and Proteobacteria phyla and a lower abundance of Firmicutes phyla in SCH-N when compared with HC. Besides, we identified a diagnostic potential panel comprising six genera (Coprococcus, Monoglobus, Prevotellaceae_NK3B31_group, Escherichia-Shigella, Dorea, and Butyricicoccus) that can distinguish SCH-N from HC (area under the curve = 0.939). However, the difference in microbial composition between the SCH-N and SCH-P is much less than that between SCH-N and the HC, and SCH-N and SCH-P cannot be effectively distinguished by gut microbiota.

CONCLUSION

The composition of gut microbiota was changed in the patients with SCH-N, which may help in further understanding of pathogenesis in young adults with SCH-N.

Antipsychotic prescribing in GMS paediatric and young adult population in Ireland 2005-2015: repeated cross-sectional study

OBJECTIVES

To examine the rates of antipsychotic prescribing in the Irish paediatric and young adult population enrolled in the Irish General Medical Services Scheme pharmacy claims database from the Health Service Executive Primary Care Reimbursement Services database, with a focus on age and sex differences. To examine concomitant prescribing of certain other related medicines in this population.

METHODS

Data were obtained from the Irish General Medical Services (GMS) scheme pharmacy claims database from the Health Service Executive (HSE) - Primary Care Reimbursement Services (PCRS). Participants included children aged <16 years and youth aged 16-24 years availing of medicines under the HSE-PCRS GMS scheme between January 2005 and December 2015. Outcome measures included prescribing rates of antipsychotics from 2005 to 2015, differences in prescribing rates between different ages and sexes, and percentage of concomitant prescriptions for antidepressants, psychostimulants, anxiolytics and hypnosedatives.

RESULTS

Overall the trend in prescribing rates of antipsychotic medications was stable at 3.94/1000 in 2005 compared with 3.97/1000 in 2015 for children <16 years, and 48.37/1000 eligible population in 2005 compared to 39.64/1000 in 2015 for those aged 16-24. There was a significant decrease in prescribing rates for males in the 16-24 age group.

CONCLUSIONS

While rates of antipsychotic prescribing have decreased or remained stable over the timeframe of the study, we did find a significant proportion of this population were prescribed antipsychotics. This study also shows that co-prescribing of antidepressants increased and highlights the need for guidelines for antipsychotic prescribing in children and youth in terms of clinical indication, monitoring, co-prescribing and treatment duration.

Psychopharmacological Considerations for Gender-Affirming Hormone Therapy

ABSTRACT

The field of transgender health has grown exponentially since the early 2010s. While this increased visibility has not been without controversy, there is growing acknowledgement of the needs of transgender, nonbinary, and gender expansive (TNG) patients and the health disparities they experience compared to the cisgender population. There is also increased interest among clinicians and trainees in providing gender-affirming care in all medical specialties. This is particularly relevant in psychiatry as mental health disparities in TNG patients have been well-documented. TNG patients experience significant minority stress and higher rates of psychiatric illness, self-harm, suicidality, and psychiatric hospitalization compared to their cisgender peers. In this review, we will cover potential interactions and side effects relevant to psychiatric medication management for the three most common medication classes prescribed as part of gender-affirming hormone therapy (GAHT): gonadotropin-releasing hormone receptor agonists, estradiol, and testosterone. Although no studies directly examining the efficacy of psychiatric medications or their interactions with GAHT for TNG patients have been published yet, we have synthesized the existing literature from both cisgender and TNG patients to shed light on health care disparities seen in TNG patients. Since clinicians' lack of comfort and familiarity with gender-affirming care contributes significantly to these disparities, we hope this narrative review will help psychiatric prescribers provide TNG patients with the same quality of care that cisgender patients receive.

Olanzapine decreased osteocyte maturation and Wnt/β-catenin signaling during loading of the alveolar bone in rats

Several studies indicate the influence of olanzapine on bone metabolism; however, the results are contradictory. We evaluated the effects of olanzapine on the Wnt/β-catenin signaling pathway, physiological alveolar bone turnover, and alveolar bone modeling due to an applied orthodontic force. Adult male rats (n=48) were treated with either olanzapine or a vehicle for 21 days; then 8 rats from each group were sacrificed and the rest were divided into 4 groups: control, appliance-only, olanzapine-only, and olanzapine-appliance. The rats in the appliance groups were mounted with a superelastic closed coil spring that maintained constant orthodontic force between molars and incisors. We studied the effects of olanzapine on physiological alveolar bone turnover on day 21 of the experiment, and on alveolar bone modeling due to orthodontic force on day 56. We determined tooth movement, alveolar bone volume, activity of bone-specific cells, serum alkaline phosphatase (ALP) activity, and gene expression levels of Wnt/β-catenin signaling target genes. During forced bone modeling, olanzapine increased osteoblast volume (P<0.0001) and ALP activity (P=0.0011) and decreased osteoclast volume (P<0.0001) and gene expression of the Wnt/β-catenin signaling target genes Fosl1, Axin2, and Dkk1(P=0.001, P=0.0076, and P=0.036, respectively), and the osteocyte markers Sost and Dmp1 (P=0.0432 and P=0.0021, respectively). Similar results were obtained during physiological alveolar bone turnover on day 21, when olanzapine downregulated the gene expression of osteocyte markers and Wnt/β-catenin signaling target genes. We concluded that olanzapine attenuated osteocyte maturation during forced bone modeling and physiological alveolar bone turnover, potentially through downregulation of the Wnt/β-catenin signaling pathway.

Effects of methylphenidate on femoral bone growth in male rats

The use of Methylphenidate (MP) can have adverse effects on bone growth and mineralization. This study aimed to investigate the underlying pathophysiology of MP-induced skeletal deficits in growing rats using stereological and immunohistochemical methods. Male rats, aged 4 weeks, were orally treated with MP through an 8-h/day water drinking protocol. The rats (n=30) were randomly divided into three groups: MP-High Dose (30/60 mg/kg/day MP), MP-Low Dose (4/10 mg/kg/day MP), and control (water only). After 13 weeks, the femoral bones were assessed using calliper measurements, dual-energy X-ray absorptiometry, and biomechanical evaluation. The total femur volume, cartilage volume, growth zone volume, and volume fractions were determined using the Cavalieri method. Immunohistochemical analyses were conducted using alkaline phosphatase and anti-calpain antibody staining. Rats exposed to MP exhibited significant reductions in weight gain, femoral growth, bone mineralization, and biomechanical integrity compared to the control group. The total femoral volume of MP-treated rats was significantly lower than that of the control group. The MP-High Dose group showed significantly higher ratios of total cartilage volume/total femoral volume and total growth zone volume/total femoral volume than the other groups. Immunohistochemical evaluation of the growth plate revealed reduced osteoblastic activity and decreased intracellular calcium deposition with chronic MP exposure. The possible mechanism of MP-induced skeletal growth retardation may involve the inhibition of intracellular calcium deposition in chondrocytes of the hypertrophic zone in the growth plate. In this way, MP may hinder the differentiation of cartilage tissue from bone tissue, resulting in reduced bone growth and mineralization.

Accidental Falls in Patients with Hyperkinetic Movement Disorders: A Systematic Review

Background:

The significance of falls and their repercussions in Parkinson’s disease has been extensively researched. However, despite potentially serious effects on health and quality of life and negative impact on the healthcare system, there is not a sufficient understanding of the role of falls in hyperkinetic movement disorders (HKMDs). This review aims to provide an overview of the prevalence of falls, injuries, and preventive measures in the most common HKMDs.

Methods:

Studies up to May 1, 2022 were searched in PubMed using Medical Subjects Headings of relatively prevalent HKMDs associated with the terms “accidental falls”, “injuries”, “fractures”, and “accident prevention”.

Results:

In our review of 37 studies out of 155, we found evidence that for several HKMDs, such as spinocerebellar ataxia, essential tremor, Huntington’s disease, and dystonia, fall risk is increased. Falls were reported in up to 84% of spinocerebellar ataxia patients, 59% of essential tremor patients, and 79% of Huntington’s patients, with 65% of the latter falling frequently. Injuries occurred in up to 73% in Huntington and 74% in ataxia patients. Most of the common diseases characterized by HKMDs were investigated for both fall causes and consequences, but prevention studies were limited to spinocerebellar ataxia and Huntington’s disease.

Discussion:

The limited available data suggest that patients with several HKMDs can be considered to be at increased risk of falling and that the consequences can be serious. As a result, physicians should be advised to include fall exploration in their routine workup and provide advice for safer mobility. In general, more research into fall-related concerns in HKMDs is necessary.

Highlights:

In contrast to Parkinson’s disease, the prevalence of accidental falls, their repercussions, and preventive strategies are under-investigated in hyperkinetic movement disorders (HKMDs). Several HKMDs such as essential tremor, ataxia, and Huntington’s disease have reported fall rates of up to 84% and fall-related injury rates of up to 74%. Therefore, routine examinations of HKMD patients should include a fall exploration and provide advice on safe mobility.

A Meta-Analysis of Antipsychotic-Induced Hypo- and Hyperprolactinemia in Children and Adolescents

Objective: Antipsychotic-related prolactin changes may expose children and adolescents to severe adverse reactions (ARs) related to pubertal development and growth. We therefore aimed to assess the effects of antipsychotics on prolactin levels and associated somatic ARs in children and adolescents. Methods: We systematically searched PubMed and CENTRAL for placebo-controlled randomized trials of antipsychotics in children and adolescents aged ≤18 years, reporting prolactin levels and related ARs. We conducted a random-effect meta-analysis and assessed risk of bias version 2 (ROB2). Results: Thirty-two randomized controlled trials with an average trial duration of 6 weeks, covering 4643 participants with an average age of 13 years and a male majority of 65.3%. Risk of bias across domains was low or unclear. The following antipsychotic compounds: aripiprazole (n = 810), asenapine (n = 506), lurasidone (n = 314), olanzapine (n = 179), paliperidone (n = 149), quetiapine (n = 381), risperidone (n = 609), and ziprasidone (n = 16) were compared with placebo (n = 1658). Compared with placebo, statistically significant higher prolactin increase occurred with risperidone (mean difference [MD] = 28.24 ng/mL), paliperidone (20.98 ng/mL), and olanzapine (11.34 ng/mL). Aripiprazole significantly decreased prolactin (MD = -4.91 ng/mL), whereas quetiapine, lurasidone, and asenapine were not associated with significantly different prolactin levels than placebo. Our results on ziprasidone are based on a single study, making it insufficient to draw strong conclusions. On average, 20.8% of patients treated with antipsychotic developed levels of prolactin that were too high (hyperprolactinemia), whereas only 1.03% of patients reported prolactin-related ARs. Data were highly limited for long-term effects. Conclusions: In children and adolescents, risperidone, paliperidone, and olanzapine are associated with significant prolactin increase, whereas aripiprazole is associated with significant decrease. Despite the significant changes in prolactin level, few ARs were reported. Study protocol on PROSPERO: CRD42018116451.

Review of the Long-Term Effect of the Atypical Antipsychotic Medication on the Bone Mineral Density of the Pediatric Patient with Consideration of Autism Spectrum Disorder

Objectives:

To shed some light on the understudied complication of chronic prolonged exposure to antipsychotics (AP) in children with consideration to with autism spectrum disorder (ASD).

Methods:

We electronically searched PubMed, Google Scholar, clinical trial.gov, and Medline Database of clinical studies up to June 2021. We used the following keywords: “bone mineral density, osteoporosis, osteopenia, bone loss, bone changes” AND “antipsychotics, SGAs, atypical antipsychotics” AND “pediatric, adolescent, young, youth, children.” We used [Mesh] Term for “antipsychotics agent” and “bone mineral density” and “autism spectrum disorder” and “child.” We retrieved relevant observational studies, reviews, case series, and randomized clinical trials.

Results:

Yvette Roke et al., in 2012, reported in a retrospective observational study that lumbar spine bone mineral density (BMD) and the biochemical bone marker were lower in the AP-treated boy with hyperprolactinemia in comparison to the non-AP-treated group, while a retrospective observational study of institutional adolescents with a psychiatric condition, carried out by Bonnot et al. in 2011, found significant vitamin D deficiency in psychiatric inpatient adolescents that is unrelated to the specific APs. Third, Calarge et al. in a 2010 retrospective observational study have reported a significant reduction in BMD in adolescents with risperidone-induced hyperprolactinemia and selective serotonin reuptake inhibitor (SSRI) compared to another group with risperidone-induced hyperprolactinemia without SSRI. On the other hand, Nivin A. Nagiub et al. (2019) in the cross-sectional study found no correlation between BMD and AP use in children with ASD. Houghton et al., in 2021, found a high fracture prevalence of 38% with aripiprazole compared to risperidone in children with ASD.

Conclusion:

Clinicians should be aware of the potential negative effects of APs on BMD, considerably in children with ASD that has additional risk factors for osteoporosis and bone disease. A provider needs to utilize more sensitive screening and diagnostic tools; the pediatric physician should evaluate other risk factors to prevent early osteopenia and bone fracture in children with ASD who are on chronic psychotropic medication, before adjusting to the AP medication.

Association between Anti-Psychotic Drugs Use and Hip Fractures in Patients with Dementia: A Nationwide Population-Based Study

Background: People with dementia are a high-risk group for hip fractures. Although the increased risk of hip fractures associated with antipsychotic drugs (APD) is found in older populations, little is known about the risk for people with dementia living in Asia. We aimed to investigate the association between hip fractures and the characteristics of APD use in patients with dementia. Methods: A nested case-control analysis was conducted on a nationwide cohort in Taiwan. People with diagnoses of dementia during 2003–2012 were identified. Conditional logistic regression analysis was performed, and adjusted odds ratios (aORs) were calculated with a 95% confidence interval (CI) to estimate the risk of hip fractures. Results: APD use was associated with an increased risk of hip fractures in patients with dementia; current use or combined use of first and second generations of APDs had even higher risks. Regarding the duration of APD use, a U-shape curve of hip fracture risk was noted, and the risk peaked during 0–15 days and >215 days of exposure (aOR = 1.46, 95% CI 1.37–1.57; aOR = 1.47, 95% CI 1.37–1.58; respectively). Considering the doses of APDs, the hip fracture risk was significantly increased with all four levels of the cumulative doses and average daily doses and peaked in the group with the highest average daily dose. Conclusions: The findings suggest that caution must be taken when initiating APD use in patients with dementia, even in a small dose, and mixed types of APD prescriptions should be administered with care. Furthermore, frequent evaluation of the possibility of tapering or withdrawal of the medication is necessary, as the risk does not attenuate after long-term use.

Risperidone versus aripiprazole fracture risk in children and adolescents with autism spectrum disorders

Risperidone and aripiprazole, commonly used antipsychotics in children with autism spectrum disorder (ASD), have previously been associated with elevated fracture risk in other populations. The aim of this study was to evaluate and compare the risk of fracture among children with ASD using risperidone or aripiprazole. This was a retrospective, propensity-score matched cohort study, set between January 2013 and December 2018. We used the MarketScan Medicaid insurance data, which covers multiple states of the United States. We included ASD children aged 2-18 years, who were new users of aripiprazole or risperidone and with no prior history of antipsychotic use or fractures. The main exposure was the continued use of aripiprazole or risperidone. The incidence rates of any fracture during follow-up were evaluated, and the risk between aripiprazole and risperidone was compared via Cox-proportional hazard models. Results were stratified by age, sex, duration of exposure and fracture site. In total, 3312 patients (78% male; mean [SD] age 11.0 [3.7] years) were identified for each cohort. Over the full duration of follow-up, fracture incidence rates per 1000 patient-years were 23.2 for risperidone and 38.4 for aripiprazole (hazard ratio and 95% confidence interval: 0.60 [0.44-0.83]). Risks were similar between cohorts throughout the first 180 days on treatment, but significantly higher in the aripiprazole group thereafter. Extremity fractures drove most of the increased risk, with the biggest differences in lower leg and ankle fractures. Differences widened for children aged 10 years or younger (HR [95% CI]: 0.47 [0.30-0.74]). In conclusion, compared to aripiprazole, risperidone was associated with 40% lower risk of fracture. Further analysis on the mechanism and long-term bone health of antipsychotic-treated children with ASD is warranted. LAY SUMMARY: We compared the risk of bone fractures among 6624 children with autism spectrum disorder (ASD), half of whom used risperidone and half of whom used aripiprazole. Taking other factors into account, risks were similar between the two groups throughout the first 180 days on treatment, but significantly higher in the aripiprazole group thereafter. The biggest differences were in lower leg and ankle fractures. Overall, compared with aripiprazole, risperidone was associated with 40% lower risk of fracture.

Understanding Mechanisms Underlying Non-Alcoholic Fatty Liver Disease (NAFLD) in Mental Illness: Risperidone and Olanzapine Alter the Hepatic Proteomic Signature in Mice

Patients with severe mental illness have increased mortality, often linked to cardio-metabolic disease. Non-alcoholic fatty liver disease (NAFLD) incidence is higher in patients with schizophrenia and is exacerbated with antipsychotic treatment. NAFLD is associated with obesity and insulin resistance, both of which are induced by several antipsychotic medications. NAFLD is considered an independent risk factor for cardiovascular disease, the leading cause of death for patients with severe mental illness. Although the clinical literature clearly defines increased risk of NAFLD with antipsychotic therapy, the underlying mechanisms are not understood. Given the complexity of the disorder as well as the complex pharmacology associated with atypical antipsychotic (AA) medications, we chose to use a proteomic approach in healthy mice treated with a low dose of risperidone (RIS) or olanzapine (OLAN) for 28 days to determine effects on development of NAFLD and to identify pathways impacted by AA medications, while removing confounding intrinsic effects of mental illness. Both AA drugs caused development of steatosis in comparison with vehicle controls (p < 0.01) and affected multiple pathways relating to energy metabolism, NAFLD, and immune function. AA-associated alteration in autonomic function appears to be a unifying theme in the regulation of hepatic pathology.

Dopamine suppresses osteoclast differentiation via cAMP/PKA/CREB pathway

How the nervous system regulates bone remodeling is an exciting area of emerging research in bone biology. Accumulating evidence suggest that neurotransmitter-mediated inputs from neurons may act directly on osteoclasts. Dopamine is a neurotransmitter that can be released by hypothalamic neurons to regulate bone metabolism through the hypothalamic-pituitary-gonadal axis. Dopamine is also present in sympathetic nerves that penetrate skeletal structures throughout the body. It has been shown that dopamine suppresses osteoclast differentiation via a D2-like receptors (D2R)-dependent manner, but the intracellular secondary signaling pathway has not been elucidated. In this study, we found that cAMP-response element binding protein (CREB) activity responds to dopamine treatment during osteoclastogenesis. Considering the critical role of CREB in osteoclastogenesis, we hypothesize that CREB may be a critical target in dopamine's regulation of osteoclast differentiation. We confirmed that D2R is also present in RAW cells and activated by dopamine. Binding of dopamine to D2R inhibits the cyclic adenosine monophosphate (cAMP)/protein kinase A (PKA) signaling pathway which ultimately decreases CREB phosphorylation during osteoclastogenesis. This was also associated with diminished expression of osteoclast markers that are downstream of CREB. Pharmacological activation of adenylate cyclase (to increase cAMP production) and PKA reverses the effect of dopamine on CREB activity and osteoclastogenesis. Therefore, we have identified D2R/cAMP/PKA/CREB as a candidate pathway that mediates dopamine's inhibition of osteoclast differentiation. These findings will contribute to our understanding of how the nervous and skeletal systems interact to regulate bone remodeling. This will enable future work toward elucidating the role of the nervous system in bone development, repair, aging, and degenerative disease.

Vitamin D and Hyperkinetic Movement Disorders: A Systematic Review

Background

The importance of vitamin D deficiency in Parkinson's disease, its negative influence on bone health, and even disease pathogenesis has been studied intensively. However, despite its possible severe impact on health and quality of life, there is not a sufficient understanding of its role in other movement disorders. This systematic review aims at providing an overview of the prevalence of vitamin D deficiency, bone metabolism alterations, and fractures in each of the most common hyperkinetic movement disorders (HKMDs).

Methods

The study search was conducted through PubMed with keywords or Medical Related Subjects (MeSH) of common HKMDs linked with the terms of vitamin D, osteoporosis, injuries, and fractures.

Results

Out of 1585 studies screened 40 were included in our review. They show that there is evidence that several HKMDs, including Huntington disease, Restless Legs Syndrome, and tremor, are associated with low vitamin D serum levels in up to 83% and 89% of patients. Reduced bone mineral density associated with vitamin D insufficiency was described in Huntington disease.

Discussion

Our survey suggests that vitamin D deficiency, bone structure changes, and fractures are important but yet under-investigated issues in HKMDs. HKMDs-patients, particularly with a history of previous falls, should have their vitamin D-levels tested and supplemented where appropriate.

Highlights

Contrary to Parkinson's disease, vitamin D deficiency, and bone abnormalities are under-investigated in hyperkinetic movement disorders (HKMDs). Several HKMDs, including essential tremor, RLS, and Huntington disease, are associated with vitamin D deficiency in up to 89%, the latter also with reduced bone mineral density. Testing and where appropriate supplementation is recommended.

Risperidone accelerates bone loss in rats with autistic-like deficits induced by maternal lipopolysaccharides exposure

AIMS

Patients with neurodevelopmental disorders, usually suffer from bone diseases. Many studies have revealed a higher risk of fracture after atypical antipsychotic drug Risperidone (RIS) treatment, which is usually used to treat such disorders. It remains debatable whether neurodevelopmental disorders by itself are the cause of bone diseases or pharmacotherapy may be the reason.

MATERIALS AND METHODS

This study attempts to evaluate the biomechanical, histological, stereological, and molecular properties of bones in the offspring of Lipopolysaccharide (LPS) and saline-treated mothers that received saline, drug vehicle or the atypical antipsychotic drug risperidone (RIS) at different days of postnatal development. After postnatal drug treatment, animals were assessed for autistic-like behaviors. Then their bones were taken for evaluations.

RESULTS

Maternal LPS exposure resulted in deficits in all behavioral tests and RIS ameliorated these behaviors (p < 0.01& p < 0.05). The administration of LPS and RIS individually led to a significant decrease in the biomechanical parameters such as bone stiffness, strength and the energy used to fracture of bone. The numerical density of osteocalcin-positive cells were significantly decreased in these groups. These rats also had decreased RUNX2 and osteocalcin gene expression. When LPS rats were treated with RIS, these conditions were accelerated (p < 0.001).

DISCUSSIONS

The results of our preclinical study, consistent with previous studies in animals, explore that autistic-like deficits induced by prenatal exposure to LPS, can reduce bone stability and bone mass similar to those observed in neurodevelopmental disorders, and, for the first time, reveal that this condition worsened when these animals were treated with RIS.

[Evidence-based treatment of acute psychotic episode and schizophrenia in children and adolescents]

Children and adolescents are a special group in the context of psychopharmacotherapy. Given the limited choice of registered antipsychotics permitted in childhood, caution should be exercised in the choice of medication. This literature review reviews the current evidence base for pharmacotherapy of acute psychotic episode and schizophrenia in children and adolescents. The results of major systematic reviews and meta-analyses are compared. Meta-analyses of pharmacotherapy studies of the first psychotic episode are considered separately. Antipsychotics of the first and second generation are comparable in effectiveness for children and adolescents with acute psychotic episode. Olanzapine demonstrates higher efficacy in reducing negative symptoms. Ziprasidone and asenapine are less effective in treating schizophrenia in children and adolescents than other antipsychotics. Compared to adults, children and adolescents are at higher risk of metabolic impairments when taking antipsychotics.

Dopamine D1 receptor-mediated activation of the ERK signaling pathway is involved in the osteogenic differentiation of bone mesenchymal stem cells

BACKGROUND

Osteogenic differentiation of bone mesenchymal stem cells (BMSCs) is regulated by numerous signaling pathways. Dopamine (DA), a neurotransmitter, has previously been demonstrated to induce new bone formation by stimulating the receptors on BMSCs, but the essential mediators of DA-induced osteogenic signaling remain unclear.

METHODS

In this work, we evaluated the influence of both dopamine D1 and D2 receptor activation on BMSC osteogenic differentiation. Gene and protein expression of osteogenic-related markers were tested. The direct binding of transcriptional factor, Runx2, to those markers was also investigated. Additionally, cellular differentiation-associated signaling pathways were evaluated.

RESULTS

We showed that the expression level of the D1 receptor on BMSCs increased during osteogenic differentiation. A D1 receptor agonist, similar to DA, induced the osteogenic differentiation of BMSCs, and this phenomenon was effectively inhibited by a D1 receptor antagonist or by D1 receptor knockdown. Furthermore, the suppression of protein kinase A (PKA), an important kinase downstream of the D1 receptor, successfully inhibited DA-induced BMSC osteogenic differentiation and decreased the phosphorylation of ERK1/2. Compared with P38, MAPK, and JNK, DA mainly induced the phosphorylation of ERK1/2 and led to the upregulation of Runx2 transcriptional activity, thus facilitating BMSC osteogenic differentiation. On the other hand, an ERK1/2 inhibitor could reverse these effects.

CONCLUSIONS

Taken together, these results suggest that ERK signaling may play an essential role in coordinating the DA-induced osteogenic differentiation of BMSCs by D1 receptor activation.

Exploring mechanisms of increased cardiovascular disease risk with antipsychotic medications: Risperidone alters the cardiac proteomic signature in mice

Atypical antipsychotic (AA) medications including risperidone (RIS) and olanzapine (OLAN) are FDA approved for the treatment of psychiatric disorders including schizophrenia, bipolar disorder and depression. Clinical side effects of AA medications include obesity, insulin resistance, dyslipidemia, hypertension and increased cardiovascular disease risk. Despite the known pharmacology of these AA medications, the mechanisms contributing to adverse metabolic side-effects are not well understood. To evaluate drug-associated effects on the heart, we assessed changes in the cardiac proteomic signature in mice administered for 4 weeks with clinically relevant exposure of RIS or OLAN. Using proteomic and gene enrichment analysis, we identified differentially expressed (DE) proteins in both RIS- and OLAN-treated mouse hearts (p < 0.05), including proteins comprising mitochondrial respiratory complex I and pathways involved in mitochondrial function and oxidative phosphorylation. A subset of DE proteins identified were further validated by both western blotting and quantitative real-time PCR. Histological evaluation of hearts indicated that AA-associated aberrant cardiac gene expression occurs prior to the onset of gross pathomorphological changes. Additionally, RIS treatment altered cardiac mitochondrial oxygen consumption and whole body energy expenditure. Our study provides insight into the mechanisms underlying increased patient risk for adverse cardiac outcomes with chronic treatment of AA medications.

Calcium and Vitamin D Supplementation in Boys with Risperidone-Induced Hyperprolactinemia: A Randomized, Placebo-Controlled Pilot Study

BACKGROUND

The chronic use of antipsychotics has been associated with impaired bone mineralization, partially mediated by hyperprolactinemia. We examined if calcium and vitamin D supplementation promote bone mineral accrual in boys with risperidone-induced hyperprolactinemia.

METHODS

Between February 2009 and November 2013, medically healthy, 5- to 17-year-old boys were enrolled in a 36-week double-blind, placebo-controlled study, examining the skeletal effects of supplementation with 1250 mg calcium carbonate and 400 IU of vitamin D3 in risperidone-induced hyperprolactinemia. Anthropometric, dietary, physical activity, and psychiatric assessments were conducted at baseline and week 18 and 36. Plasma prolactin and vitamin D concentrations were measured at baseline and week 36. Total body less head bone mineral content (BMC) and radius trabecular bone mineral density (BMD) were measured at baseline, week 18, and week 36, using dual-energy X-ray absorptiometry and peripheral quantitative computed tomography, respectively. Linear mixed-effects regression analysis examined the longitudinal effect of treatment on skeletal outcomes.

RESULTS

Forty-seven boys (mean age: 11.0 ± 2.6 years) were randomized and 38 completed the study. At study entry, the average dietary calcium intake was below the recommended limit, but the average vitamin D concentration was normal. Calcium and vitamin D supplementation failed to significantly increase BMC or trabecular BMD. It also failed to affect several other skeletal and anthropometric outcomes, including plasma vitamin D concentration.

CONCLUSIONS

In this 9-month long pilot study, supplementation with a modest dose of calcium and vitamin D did not increase bone mass accrual in risperidone-treated boys with hyperprolactinemia. Alternative approaches should be investigated to optimize bone health in this population to prevent future morbidity and premature mortality. ClinicalTrials.gov Identifier: NCT00799383.

Fluoxetine Administration in Juvenile Monkeys: Implications for Pharmacotherapy in Children

Fluoxetine therapy has been approved for children with major depressive disorder and obsessive compulsive disorder for over 14 years and has expanded to other childhood behavior disorders. As use increases, more detail on fluoxetine effects during juvenile brain development can help maintain safe and effective use of this therapy. Here, a narrative review is provided of previously published findings from a large nonhuman primate project. Fluoxetine was administered to juvenile male rhesus monkeys for an extended period (2 years) prior to puberty. Compared to controls, treated monkeys showed sleep disruption, facilitated social interaction, greater impulsivity, and impaired sustained attention during treatment. No effects on growth were seen. Metabolomics assays characterized a distinctive response to fluoxetine and demonstrated individual differences that were related to the impulsivity measure. Fluoxetine interactions with monoamine oxidase A polymorphisms that influenced behavior and metabolomics markers were an important, previously unrecognized finding of our studies. After treatment was discontinued, some behavioral effects persisted, but short-term memory and cognitive flexibility testing did not show drug effects. This detailed experimental work can contribute to clinical research and continued safe and effective fluoxetine pharmacotherapy in children.

Bone Mass in Boys with Autism Spectrum Disorder

To examine bone mass in children and adolescents with autism spectrum disorders (ASD). Risperidone-treated 5 to 17 year-old males underwent anthropometric and bone measurements, using dual-energy X-ray absorptiometry and peripheral quantitative computed tomography. Multivariable linear regression analysis models examined whether skeletal outcomes differed among participants with (n = 30) versus without ASD (n = 156). After adjusting for potential covariates, having ASD was associated with significantly lower trabecular bone mineral density and bone strength at the radius, and with marginally lower total body less head bone mineral content (p < 0.09). No differences at the lumbar spine were observed. ASD are associated with lower bone mass. Future studies should investigate interventions to optimize skeletal health in ASD.

Elucidating the Mechanism(s) Underlying Antipsychotic and Antidepressant-Mediated Fractures

Mood spectrum disorders and medications used to treat these disorders, such as atypical antipsychotic drugs (AA), are associated with metabolic and endocrine side effects including obesity, dyslipidemia, hyperglycemia and increased risk of fractures. Antidepressant medications, including selective serotonin reuptake inhibitors (SSRI), have also been reported to increase fracture risk in some patients. The pharmacology underlying the increased risk of fractures is currently unknown. Possible mechanisms include alternations in dopaminergic and/or serotonergic signaling pathways. As these medications distribute to the bone marrow as well as to the brain, it is possible that drug-induced fractures are due to both centrally mediated effects as well as direct effects on bone turnover. Given the growing patient population that is prescribed these medications for both on- and off-label indications, understanding the level of risk and the mechanisms underlying drug-induced fractures is important for informing both prescribing and patient monitoring practices.

Antipsychotic-induced hyperprolactinemia in Tourette syndrome

For many years, Tourette syndrome (TS) was considered to be a rare disorder, but tics and TS are now recognized as fairly common childhood-onset conditions. Children and adolescents with TS are frequently treated with antipsychotics, either as monotherapy or in combination with psychostimulants, melatonin and selective serotonin reuptake inhibitors (SSRIs). Antipsychotics are most often used in schizophrenia and related psychotic disorders, and in these conditions hyperprolactinemia is one of the most common adverse effects associated with antipsychotics, occurring in 40-50% of patients. We describe two patients with TS who experienced antipsychotic-induced hyperprolactinemia. Treatment options generally consist of dose reduction or switching from typical to atypical antipsychotics. However, diminishing dosages can lead to exacerbations of tics. Also, not all atypical antipsychotics have the same pharmacologic properties required to normalize prolactin levels. The choice of treatment may also be affected by the patient's age and sex. These factors are discussed in relation to these cases, and illustrated by the results of therapeutic interventions over the years.

Relationship between antipsychotic medication, serum prolactin levels and osteoporosis/osteoporotic fractures in patients with schizophrenia: a critical literature review

INTRODUCTION

Using an antipsychotic medication can increase prolactin (PRL) levels, causing hyperprolactinemia (HPRL). Although the occurrence of osteoporosis within the population of patients with schizophrenia has been recognized, the precise nature of the association between antipsychotic treatment, PRL, osteoporosis, and the disease itself seems to be elusive.

AREAS COVERED

The aim of this review is to critically review the literature regarding the association between osteoporosis and PRL and to summarize the available evidence with respect to the impact of PRL-elevating antipsychotics on bone mineral density (BMD) and fractures in non-elderly patients with schizophrenia.

EXPERT OPINION

Although long-standing HPRL can have an impact on the rate of bone metabolism and, when associated with hypogonadism, may lead to decreased bone density in both female and male subjects, the relative contribution of antipsychotic-induced HPRL in bone mineral loss in patients with schizophrenia remains unclear. Methodological shortcomings of existing studies, including the lack of prospective data and the focus on measurements of BMD instead of bone turnover markers, preclude definitive conclusions regarding the relationship between PRL-raising antipsychotics and BMD loss in patients with schizophrenia. Therefore, more well conducted prospective trials of these biomarkers are necessary to establish the precise relationship between antipsychotics, PRL levels and osteoporosis/osteoporotic risk.

Dopamine receptors - IUPHAR Review 13

The variety of physiological functions controlled by dopamine in the brain and periphery is mediated by the D1, D2, D3, D4 and D5 dopamine GPCRs. Drugs acting on dopamine receptors are significant tools for the management of several neuropsychiatric disorders including schizophrenia, bipolar disorder, depression and Parkinson's disease. Recent investigations of dopamine receptor signalling have shown that dopamine receptors, apart from their canonical action on cAMP-mediated signalling, can regulate a myriad of cellular responses to fine-tune the expression of dopamine-associated behaviours and functions. Such signalling mechanisms may involve alternate G protein coupling or non-G protein mechanisms involving ion channels, receptor tyrosine kinases or proteins such as β-arrestins that are classically involved in GPCR desensitization. Another level of complexity is the growing appreciation of the physiological roles played by dopamine receptor heteromers. Applications of new in vivo techniques have significantly furthered the understanding of the physiological functions played by dopamine receptors. Here we provide an update of the current knowledge regarding the complex biology, signalling, physiology and pharmacology of dopamine receptors.

Propranolol Attenuates Risperidone-Induced Trabecular Bone Loss in Female Mice

Atypical antipsychotic (AA) drugs cause significant metabolic side effects, and clinical data are emerging that demonstrate increased fracture risk and bone loss after treatment with the AA, risperidone (RIS). The pharmacology underlying the adverse effects on bone is unknown. However, RIS action in the central nervous system could be responsible because the sympathetic nervous system (SNS) is known to uncouple bone remodeling. RIS treatment in mice significantly lowered trabecular bone volume fraction (bone volume/total volume), owing to increased osteoclast-mediated erosion and reduced osteoblast-mediated bone formation. Daytime energy expenditure was also increased and was temporally associated with the plasma concentration of RIS. Even a single dose of RIS transiently elevated expression of brown adipose tissue markers of SNS activity and thermogenesis, Pgc1a and Ucp1. Rankl, an osteoclast recruitment factor regulated by the SNS, was also increased 1 hour after a single dose of RIS. Thus, we inferred that bone loss from RIS was regulated, at least in part, by the SNS. To test this, we administered RIS or vehicle to mice that were also receiving the nonselective β-blocker propranolol. Strikingly, RIS did not cause any changes in trabecular bone volume/total volume, erosion, or formation while propranolol was present. Furthermore, β2-adrenergic receptor null (Adrb2(-/-)) mice were also protected from RIS-induced bone loss. This is the first report to demonstrate SNS-mediated bone loss from any AA. Because AA medications are widely prescribed, especially to young adults, clinical studies are needed to assess whether β-blockers will prevent bone loss in this vulnerable population.

The effect of psychostimulants on skeletal health in boys co-treated with risperidone

OBJECTIVES

To examine the skeletal effects of chronic psychostimulant treatment in children and adolescents.

STUDY DESIGN

Medically healthy 5- to 17-year-old males from 4 different clinic-based studies were combined for this analysis. They were divided by psychostimulant use into 3 groups: none to negligible, intermittent, and continuous use. Most (95%) had also received risperidone for 6 months or more. Treatment history was extracted from medical and pharmacy records. Anthropometric and bone measurements, using dual-energy x-ray absorptiometry and peripheral quantitative computed tomography, were obtained at each research visit. Multivariable linear regression analysis models examined whether age-sex-specific height Z-score and skeletal outcomes differed among the 3 psychostimulant-use groups.

RESULTS

The sample consisted of 194 males with a mean age of 11.7 ± 2.8 years at study entry. The majority had an externalizing disorder. There was no significant difference across the 3 treatment groups in height Z-score or in skeletal outcomes at the radius, lumbar spine, or whole body. One hundred forty-four boys had valid follow-up skeletal data 1.4 ± 0.7 years after study entry. Again, neither height Z-score nor the skeletal outcomes were different among those who remained on psychostimulants between the 2 visits, started psychostimulants anew, or had not taken psychostimulants.

CONCLUSIONS

Following chronic treatment, psychostimulants did not appear to significantly affect bone mass accrual in children and adolescents taking risperidone. There was a small, but statistically not significant, negative impact on longitudinal growth.

Longitudinal examination of the skeletal effects of selective serotonin reuptake inhibitors and risperidone in boys

OBJECTIVE

In a previous cross-sectional study, we found lower bone mass during treatment with selective serotonin reuptake inhibitors (SSRIs) and risperidone in youths. Here, we evaluate the skeletal effects of these psychotropics at follow-up.

METHOD

Between April 2005 and July 2011, medically healthy 7- to 17-year-old males treated with risperidone for 6 months or more were enrolled through child psychiatry outpatient clinics and returned for follow-up 1.5 years later. Treatment history was extracted from the medical and pharmacy records. Anthropometric, laboratory, and bone mass measurements were obtained. Multivariable linear regression analyses compared participants who remained on risperidone at follow-up to those who had discontinued risperidone treatment as well as SSRI-treated versus SSRI-unexposed participants.

RESULTS

The sample consisted of 94 boys with a mean age of 11.8 ± 2.7 years at study entry. The majority had an externalizing disorder and had received risperidone and SSRIs for 2.5 ± 1.7 years and 1.6 ± 1.9 years, respectively, at study entry. By follow-up, 26% (n = 24) had discontinued risperidone. Compared to discontinuing risperidone, continuing it was associated with a decline in participants' age-sex-height-race-specific areal bone mineral density (BMD) z score at the lumbar spine (P < .04) and failure to increase radius trabecular volumetric BMD (P < .03), after accounting for significant covariates. In addition, receiving an SSRI was associated with reduced lumbar spine areal BMD z score and radius trabecular volumetric BMD at both study entry (P < .02 and P < .03, respectively) and follow-up (P < .06 and P < .03, respectively), but without further decline between the 2 visits.

CONCLUSIONS

Chronic SSRI treatment in children and adolescents is associated with reduced, albeit stable, bone mass for age, while chronic risperidone treatment is associated with failure to accrue bone mass.

Efficacy and safety of pharmacological and psychological interventions for the treatment of psychosis and schizophrenia in children, adolescents and young adults: a systematic review and meta-analysis

BACKGROUND

Studies report contrasting results regarding the efficacy and safety of pharmacological, psychological, and combined interventions in psychosis and schizophrenia in children, adolescents and young adults.

METHODS

Systematic review and meta-analysis. Embase, Medline, PreMedline, PsycINFO, and CENTRAL were searched to July 2013 without restriction to publication status. Randomised trials comparing any pharmacological, psychological, or combined intervention for psychosis and schizophrenia in children, adolescents and young adults were included. Studies were assessed for bias, and GRADE criteria were used to describe the quality of the results.

RESULTS

Twenty-seven trials including 3067 participants were identified. Meta-analyses were performed for 12 comparisons: symptoms, relapse, global state, psychosocial functioning, depression, weight and discontinuation. Low quality evidence demonstrated that antipsychotics have small beneficial effects on psychotic symptoms (SMD = -0.42, 95% CI -0.58 to -0.26), and a medium adverse effect on weight gain (WMD = 1.61, 95% CI 0.61 to 2.60) and discontinuation due to side effects (RR = 2.44, 95% CI, 1.12 to 5.31). There were no trials of psychological treatments in under-18 year olds. There was no evidence of an effect of psychological interventions on psychotic symptoms in an acute episode, or relapse rate, but low quality evidence of a large effect for family plus individual CBT on the number of days to relapse (WMD = 32.25, 95% CI -36.52 to -27.98).

CONCLUSIONS

For children, adolescents and young adults, the balance of risk and benefit of antipsychotics appears less favourable than in adults. Research is needed to establish the potential for psychological treatments, alone and in combination with antipsychotics, in this population.

Adverse skeletal effects of drugs - beyond Glucocorticoids

Osteoporotic fractures are an important public health problem with significant individual and societal costs. In addition to the major risk factors for osteoporotic fracture, low bone mineral density (BMD), age, low body weight and history of fracture or falls, some drugs are now considered to be important secondary risk factor for bone loss and fracture, particularly amongst predisposed individuals. Currently available data are often generated from small observational clinical studies, making risk assessment and development of management guidelines difficult. In many cases, the exposed population has a low baseline risk for fracture and additional assessment and treatment may not be necessary. In this review, we focus on drugs other than glucocorticoids identified as potentially causing adverse skeletal effects, summarizing the existing evidence from preclinical and clinical studies, and suggest recommendations for patient management.

Cardiometabolic outcomes in children and adolescents following discontinuation of long-term risperidone treatment

OBJECTIVE

Second-generation antipsychotics (SGAs) cause weight gain and cardiometabolic abnormalities in children and adolescents. Less well-investigated is the outcome of these adverse events following SGA discontinuation, which we examined.

METHODS

Medically healthy 7 to 17-year-old patients treated with risperidone for ≥6 months were enrolled and returned for follow-up, 1.5 years later. Treatment history was extracted from the medical and pharmacy records. Anthropometric and laboratory measurements were obtained at each research visit. Multivariable linear regression analysis and Fisher's exact test were used to compare participants who remained on risperidone at follow-up (Risp Cont Group) with those who had discontinued SGA treatment (SGA Disc Group) and those who had switched to another SGA (SGA Cont Group). Correlational analyses examined the association between change in age-sex specific body mass index (BMI) z score between study entry and follow-up and change in cardiometabolic outcomes.

RESULTS

The sample consisted of 101 participants (93% male) with a mean age of 11.7±2.6 years at study entry. The majority had an externalizing disorder and received 0.03±0.02 mg/kg/day of risperidone, for 2.5±1.6 years. At follow-up, 18% (n=18) were in the SGA Disc Group and 9% (n=9) were in the SGA Cont Group. BMI z score decreased in the SGA Disc Group, remained unchanged in the Risp Cont Group (n=74), and increased in the SGA Cont Group. Importantly, the change in BMI z score between study entry and follow-up was significantly correlated with the change in systolic and diastolic blood pressure z scores, heart rate, waist circumference, percent body fat, inflammatory markers, fasting total insulin, homeostatic model assessment insulin resistance index (HOMA-IR), C-peptide, total, low-density lipoprotein (LDL), and high-density lipoprotein (HDL) cholesterol, triglycerides, triglycerides/HDL ratio, and leptin.

CONCLUSIONS

Following several years of treatment, risperidone discontinuation is associated with a reversal of the excessive weight gain, mediated by a negative energy balance, and a corresponding improvement in cardiometabolic parameters.