The role of NMDA receptors in bipolar disorder: A systematic review.

OBJECTIVES: Glutamatergic transmission and N-methyl-D-aspartate receptors (NMDARs) have been implicated in the pathophysiology schizophrenic spectrum and major depressive disorders. Less is known about the role of NMDARs in bipolar disorder (BD). The present systematic review aimed to investigate the role of NMDARs in BD, along with its possible neurobiological and clinical implications. METHODS: We performed a computerized literature research on PubMed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement, using the following string: (("Bipolar Disorder"[Mesh]) OR (manic-depressive disorder[Mesh]) OR ("BD") OR ("MDD")) AND ((NMDA [Mesh]) OR (N-methyl-D-aspartate) OR (NMDAR[Mesh]) OR (N-methyl-D-aspartate receptor)). RESULTS: Genetic studies yield conflicting results, and the most studied candidate for an association with BD is the GRIN2B gene. Postmortem expression studies (in situ hybridization and autoradiographic and immunological studies) are also contradictory but suggest a reduced activity of NMDARs in the prefrontal, superior temporal cortex, anterior cingulate cortex, and hippocampus. CONCLUSIONS: Glutamatergic transmission and NMDARs do not appear to be primarily involved in the pathophysiology of BD, but they might be linked to the severity and chronicity of the disorder. Disease progression could be associated with a long phase of enhanced glutamatergic transmission, with ensuing excitotoxicity and neuronal damage, resulting into a reduced density of functional NMDARs.

Current nonstimulant medications for adults with attention-deficit/hyperactivity disorder.

INTRODUCTION: Stimulants, including methylphenidate and amphetamines, are the first-line pharmacological treatment of ADHD in adults. However, in patients who do not respond or poorly tolerate stimulants, non-stimulant medications are usually recommended. AREAS COVERED: The authors provide a narrative review of the literature on non-stimulant treatments for adult ADHD, including controlled and observational clinical studies conducted on adult samples. Atomoxetine has been extensively studied and showed significant efficacy in treating adult ADHD. Issues related to dosing, treatment duration, safety, and use in the case of psychiatric comorbidity are summarized. Among other compounds indicated for ADHD in adults, antidepressants sharing at least a noradrenergic or dopaminergic component, including tricyclic compounds, bupropion, and viloxazine, have shown demonstratable efficacy. Evidence is also available for antihypertensives, particularly guanfacine, as well as memantine, metadoxine, and mood stabilizers, while negative findings have emerged for galantamine, antipsychotics, and cannabinoids. EXPERT OPINION: While according to clinical guidelines, atomoxetine may serve as the only second-line option in adults with ADHD, several other nonstimulant compounds may be effectively used in order to personalize treatment based on comorbid conditions and ADHD features. Nevertheless, further research is needed to identify and test more personalized treatment strategies for adults with ADHD.

Development of a self-report screening instrument for emotional dysregulation: the Reactivity, Intensity, Polarity and Stability questionnaire, screening version (RIPoSt-SV).

BACKGROUND: Emotional dysregulation (ED) refers to the inability to manage emotional experiences or expressions hindering goal-oriented behavior. Moderate impairment on at least two domains among temper control, affective lability, and emotional over-reactivity has been proposed to identify ED in adults with attention-deficit/hyperactivity disorder (ADHD). No screening measure designed for use in diverse psychiatric samples exists. We aimed to develop a self-report screening tool for ED based on the 40-item version of the Reactivity, Intensity, Polarity, and Stability questionnaire (RIPoSt-40). METHODS: 150 adult outpatients with non-psychotic conditions were enrolled between February and July 2023 at the Second Psychiatry Unit of Pisa University Hospital. Clinically significant ED (CSED) was defined based on the previously suggested approach for ADHD. Differences between patients with and without CSED were tested. To develop our screening instrument, a decision tree algorithm was trained by hyperparameter tuning through 5-fold cross-validation in 120 subjects and tested on the remaining 30. RESULTS: 75 subjects met criteria for CSED (50 %). CSED was associated with lower age and higher prevalence of psychiatric conditions, including minor mood disorders, ADHD, cannabis use disorders, and eating disorders. We identified a decision tree consisting of six items from RIPoSt-40 that effectively detected CSED, with accuracy, sensitivity, specificity, positive and negative predictive values of 80 % or higher in both the training and testing sets. LIMITATIONS: Tertiary-level; no consensus on criteria; sample size. CONCLUSION: The screening version of the Reactivity, Intensity, Polarity, and Stability questionnaire (RIPoSt-SV) demonstrates promise as a valuable tool for ED screening in clinical settings.

History of Childhood/Adolescence Referral to Speciality Care or Treatment in Adult Patients with Attention-Deficit/Hyperactivity Disorder: Mutual Relations with Clinical Presentation, Psychiatric Comorbidity and Emotional Dysregulation.

Attention-deficit/hyperactivity disorder (ADHD) is a neurodevelopmental condition that only rarely remits in adulthood. While several studies underlined differences between child and adult ADHD, the relationship between adult clinical presentation and early referral/treatment has been rarely investigated. In our study, 100 adults with ADHD were recruited and subdivided according to a history of referral to speciality care or treatment with methylphenidate (MPH) during childhood/adolescence. The early referral was associated with a history of disruptive behaviors during childhood/adolescence. Current ADHD symptoms were more pronounced in patients first referred during childhood/adolescence but never treated with MPH. Early MPH treatment was associated with lower rates of mood disorders and lower severity of emotional dysregulation at the time of assessment. Negative emotionality mediated the relationship between MPH treatment and mood disorders comorbidity. ADHD patients first referred during childhood/adolescence are characterized by more externalizing features than those first referred in adulthood. MPH treatment during the developmental age may have a role in preventing mood disorders in patients with ADHD, possibly by reducing emotional dysregulation.