A selective review of inhibitors of protein kinase C gamma: a neuroplasticity-related common pathway for psychiatric illness

Psychotropics are currently developed and marketed with a limited understanding of their mechanism of action. The notion that protein kinase C (PKC) activity is highly relevant to learning and memory function stems from experiments in the 1980s, which associated protein kinase alpha (pka) and pkc to animal models of associative learning, opening an area of exploration for psychotropic development. The PKC family consists of several isoforms, including PKC alpha, beta1, beta1, gamma, delta and epsilon among others. In particular, PKC gamma (PRKCG) is highly brain-expressed and is singled out as a candidate for modulation in psychiatric illness. With hundreds of identified substrates, PRKCG affects multiple pathways relevant for regulation of neuronal health. In this review, converging lines of evidence are presented in the context of psychotropic drug action, which point to downregulation of PKC activity as a potential common mechanism across several psychiatric disorders. Using this mechanism through more targeted psychotropic action may then be used to develop agents that further ameliorate psychiatric symptom expression. Psychotropics including fluoxetine, tricyclics, lithium, valproate, ketamine and others are explored in relation to their effect of PKC, finding that across all drugs examined, a downregulation with chronic-but not acute-use constitutes their putative effect in ameliorating symptoms. This effect is compounded by findings that suggest that PKCs, and PRKCG in particular, promote neuroplastic effects by their downregulation. This effect is in contrast to PKC activators, which have been used in neurodegenerative disorders such as Alzheimer’s disease. Cross-disorder mechanisms need to continue to be explored in neuropsychiatric illness and targeted treatments developed in turn to address treatment-resistant conditions

Lifetime Prevalence, Age of Risk, and Etiology of Comorbid Psychiatric Disorders in Tourette Syndrome

IMPORTANCE: Tourette syndrome (TS) is characterized by high rates of psychiatric comorbidity; however, few studies have fully characterized these comorbidities. Furthermore, most studies have included relatively few participants (<200), and none has examined the ages of highest risk for each TS-associated comorbidity or their etiologic relationship to TS. OBJECTIVE: To characterize the lifetime prevalence, clinical associations, ages of highest risk, and etiology of psychiatric comorbidity among individuals with TS. DESIGN, SETTING, AND PARTICIPANTS: Cross-sectional structured diagnostic interviews conducted between April 1, 1992, and December 31, 2008, of participants with TS (n = 1374) and TS-unaffected family members (n = 1142). MAIN OUTCOMES AND MEASURES: Lifetime prevalence of comorbid DSM-IV-TR disorders, their heritabilities, ages of maximal risk, and associations with symptom severity, age at onset, and parental psychiatric history. RESULTS: The lifetime prevalence of any psychiatric comorbidity among individuals with TS was 85.7%; 57.7% of the population had 2 or more psychiatric disorders. The mean (SD) number of lifetime comorbid diagnoses was 2.1 (1.6); the mean number was 0.9 (1.3) when obsessive-compulsive disorder (OCD) and attention-deficit/hyperactivity disorder (ADHD) were excluded, and 72.1% of the individuals met the criteria for OCD or ADHD. Other disorders, including mood, anxiety, and disruptive behavior, each occurred in approximately 30% of the participants. The age of greatest risk for the onset of most comorbid psychiatric disorders was between 4 and 10 years, with the exception of eating and substance use disorders, which began in adolescence (interquartile range, 15–19 years for both). Tourette syndrome was associated with increased risk of anxiety (odds ratio [OR], 1.4; 95% CI, 1.0–1.9; P = .04) and decreased risk of substance use disorders (OR, 0.6; 95% CI, 0.3–0.9; P = .02) independent from comorbid OCD and ADHD; however, high rates of mood disorders among participants with TS (29.8%) may be accounted for by comorbid OCD (OR, 3.7; 95% CI, 2.9–4.8; P < .001). Parental history of ADHD was associated with a higher burden of non-OCD, non-ADHD comorbid psychiatric disorders (OR, 1.86; 95% CI, 1.32–2.61; P < .001). Genetic correlations between TS and mood (RhoG, 0.47), anxiety (RhoG, 0.35), and disruptive behavior disorders (RhoG, 0.48), may be accounted for by ADHD and, for mood disorders, by OCD. CONCLUSIONS AND RELEVANCE: This study is, to our knowledge, the most comprehensive of its kind. It confirms the belief that psychiatric comorbidities are common among individuals with TS, demonstrates that most comorbidities begin early in life, and indicates that certain comorbidities may be mediated by the presence of comorbid OCD or ADHD. In addition, genetic analyses suggest that some comorbidities may be more biologically related to OCD and/or ADHD rather than to TS

Rare Copy Number Variants in \u3cem\u3eNRXN1\u3c/em\u3e and \u3cem\u3eCNTN6\u3c/em\u3e Increase Risk for Tourette Syndrome

Tourette syndrome (TS) is a model neuropsychiatric disorder thought to arise from abnormal development and/or maintenance of cortico-striato-thalamo-cortical circuits. TS is highly heritable, but its underlying genetic causes are still elusive, and no genome-wide significant loci have been discovered to date. We analyzed a European ancestry sample of 2,434 TS cases and 4,093 ancestry-matched controls for rare (\u3c 1% frequency) copy-number variants (CNVs) using SNP microarray data. We observed an enrichment of global CNV burden that was prominent for large (\u3e 1 Mb), singleton events (OR = 2.28, 95% CI [1.39–3.79], p = 1.2 × 10−3) and known, pathogenic CNVs (OR = 3.03 [1.85–5.07], p = 1.5 × 10−5). We also identified two individual, genome-wide significant loci, each conferring a substantial increase in TS risk (NRXN1 deletions, OR = 20.3, 95% CI [2.6–156.2]; CNTN6 duplications, OR = 10.1, 95% CI [2.3–45.4]). Approximately 1% of TS cases carry one of these CNVs, indicating that rare structural variation contributes significantly to the genetic architecture of TS

Risperidone Treatment of Autistic Disorder: Longer-Term Benefits and Blinded Discontinuation After 6 Months

Objective: Risperidone is effective for short-term treatment of aggression, temper outbursts, and self-injurious behavior in children with autism. Because these behaviors may be chronic, there is a need to establish the efficacy and safety of longer-term treatment with this agent. Method: The authors conducted a multisite, two-part study of risperidone in children ages 5 to 17 years with autism accompanied by severe tantrums, aggression, and/or self-injurious behavior who showed a positive response in an earlier 8-week trial. Part I consisted of 4-month open-label treatment with risperidone, starting at the established optimal dose; part II was an 8-week randomized, double-blind, placebo-substitution study of risperidone withdrawal. Primary outcome measures were the Aberrant Behavior Checklist irritability subscale and the Clinical Global Impression improvement scale. Results: Part I included 63 children. The mean risperidone dose was 1.96 mg/day at entry and remained stable over 16 weeks of open treatment. The change on the Aberrant Behavior Checklist irritability subscale was small and clinically insignificant. Reasons for discontinuation of part I included loss of efficacy (N=5) and adverse effects (N=1). The subjects gained an average of 5.1 kg. Part II included 32 patients. The relapse rates were 62.5% for gradual placebo substitution and 12.5% for continued risperidone; this difference was statistically significant. Conclusions: Risperidone showed persistent efficacy and good tolerability for intermediate-length treatment of children with autism characterized by tantrums, aggression, and/or self-injurious behavior. Discontinuation after 6 months was associated with a rapid return of disruptive and aggressive behavior in most subjects

Nivel de conocimiento sobre higiene oral asociada a prevalencia de caries en adolescentes de una institución educativa pública, Celendín, 2022

Objetivo: El objetivo del estudio fue determinar el nivel de conocimiento sobre higiene oral asociada a prevalencia de caries en adolescentes de una Institución Educativa Pública, Celendín 2022. Metodología: El estudio fue básico, con diseño no experimental y corte transversal. La muestra estuvo conformada por 110 adolescentes de la institución educativa, los que cumplieron los criterios de inclusión. Se usó una encuesta para medir el nivel de conocimiento sobre higiene oral y se usó el índice CPO-D para valorar la prevalencia de caries. Resultados: No se encontró asociación entre las variables nivel de conocimiento sobre higiene oral y prevalencia de caries en los adolescentes (p= 0,731), el nivel de conocimiento fue regular (53,6 %), la prevalencia de caries fue 100 %, con una media del índice de CPO-D de 17,0, además no se halló diferencia estadística significativa (p = 0,255) entre el índice de CPO-D y el género al igual que con el grupo etario (p=0,063). Conclusión: No existió asociación entre el nivel de conocimiento sobre higiene oral y prevalencia de caries, descartando una correlación positiva y significativ

Genome-wide association study of Tourette Syndrome

Tourette Syndrome (TS) is a developmental disorder that has one of the highest familial recurrence rates among neuropsychiatric diseases with complex inheritance. However, the identification of definitive TS susceptibility genes remains elusive. Here, we report the first genome-wide association study (GWAS) of TS in 1285 cases and 4964 ancestry-matched controls of European ancestry, including two European-derived population isolates, Ashkenazi Jews from North America and Israel, and French Canadians from Quebec, Canada. In a primary meta-analysis of GWAS data from these European ancestry samples, no markers achieved a genome-wide threshold of significance (p<5 × 10−8); the top signal was found in rs7868992 on chromosome 9q32 within COL27A1 (p=1.85 × 10−6). A secondary analysis including an additional 211 cases and 285 controls from two closely-related Latin-American population isolates from the Central Valley of Costa Rica and Antioquia, Colombia also identified rs7868992 as the top signal (p=3.6 × 10−7 for the combined sample of 1496 cases and 5249 controls following imputation with 1000 Genomes data). This study lays the groundwork for the eventual identification of common TS susceptibility variants in larger cohorts and helps to provide a more complete understanding of the full genetic architecture of this disorder