ADHD - Combined Type

To identify the prevalence and types of cardiovascular abnormalities in children diagnosed with ADHD

The investigators' goal is to develop neuroimaging biomarkers to predict response to treatment with methylphenidate, which then can be used in the development of novel pharmacological treatments for attention-deficit/hyperactivity disorder (ADHD). The overall objective of this study is to measure the changes in task-related neural activity related to symptoms of ADHD (measured by functional MRI) and brain glutamate levels (measured by magnetic resonance spectroscopy, MRS) after treatment with methylphenidate (MPH). This will be a double-blind crossover of methylphenidate and placebo in adults with ADHD. Participants will complete neuropsychological testing along with fMRI and MRS scans after a single dose of each treatment.

The primary objective of this study is to explore and evaluate the use and utility of a guided Internet-delivered psychological treatment for adults with ADHD with a combined focus on: i) Evaluating the impact of potential predictors to treatment adherence, treatment response, treatment use and utilty. ii) Evaluating the feasibility, clinical benefits and implementation process of the treatment in routine outpatient care. iii) Evaluate the cost-effectiveness of the treatment program.

There are currently no approved medications for the treatment of anxiety in children and youth with neurodevelopmental disorders (NDDs), both common and rare. Sertraline, a selective serotonin reuptake inhibitor, has extensive evidence to support its use in children's and youth with anxiety but not within NDDs. More research is needed to confirm whether or not sertraline could help improve anxiety in children and youth with common and rare neurodevelopmental conditions. This is a pilot study, in which we plan to estimate the effect size of reduction in anxiety of sertraline vs. placebo. across rare and common neurodevelopmental disorders, and determine the best measure(s) to be used as a primary transdiagnostic outcome measure of anxiety, as well as diagnosis specific measures in future, larger-scale clinical trials of anxiety in NDDs.

This clinical trial aims to evaluate the feasibility and efficacy of NeuroTrainer cognitive training in improving attentional and executive control functions in students with and without attention-related difficulties.

The goal of this clinical trial\] is to learn about the effect of methylphenidate in children and adolescents with KBG syndrome. The main question it aims to answer is: • What is the effectiveness of methylphenidate on attention deficit and ADHD-related symptoms in children and adolescents with KBG syndrome? Participants will receive multiple blocks of treatment with methylphenidate and placebo and fill out various questionnaires.

Psychoneuromentalism Disorder is a disorder arising in the mind; that is related to the mental and emotional state of a person. It is the science of mental life. The body has a natural design to heal itself. This is a mental phenomena that cannot be explained, until now. Psychoneuromentalism Disorder is a new condition resulting from behavioral impairments, neurodiversity, and neurobehavioral dysfunctions that are related to the mental and emotional state of a participant.