Ali Khaleghi

Electroencephalogram complexity analysis in children with attention-deficit/hyperactivity disorder during a visual cognitive task

ABSTRACT Objective: The aim of this study was to investigate electroencephalogram (EEG) dynamics using complexity analysis in children with attention-deficit/hyperactivity disorder (ADHD) compared with healthy control children when performing a cognitive task. Method: Thirty 7–12-year-old children meeting Diagnostic and Statistical Manual of Mental Disorders–Fifth Edition (DSM–5) criteria for ADHD and 30 healthy control children underwent an EEG evaluation during a cognitive task, and Lempel–Ziv complexity (LZC) values were computed. There were no significant differences between ADHD and control groups on age and gender. Results: The mean LZC of the ADHD children was significantly larger than healthy children over the right anterior and right posterior regions during the cognitive performance. In the ADHD group, complexity of the right hemisphere was higher than that of the left hemisphere, but the complexity of the left hemisphere was higher than that of the right hemisphere in the normal group. Conclusion: Although fronto-striatal dysfunction is considered conclusive evidence for the pathophysiology of ADHD, our arithmetic mental task has provided evidence of structural and functional changes in the posterior regions and probably cerebellum in ADHD.

Is transcranial direct current stimulation an effective modality in reducing food craving? A systematic review and meta-analysis

Non-invasive electrical stimulation of the brain has recently been extensively investigated to regulate food craving. However, the existing literature is controversial and there are some important questions which need to be addressed about clinical and technical factors contributing to efficacy of this method. A systematic search was performed in reliable scientific databases, and 15 eligible studies were identified. The pooled standardized mean differences for the effects of transcranial direct current stimulation (tDCS) on Visual Analogue Scale, energy intake and food craving questionnaire were −0.78 [−1.12, −0.44], −0.91 [−1.38, −0.44], −0.54 [−0.85, −0.24], respectively. Subgroup analysis showed that the most important factors associated with the impact of tDCS on food craving were the population under study, current intensity of stimulation, and number of stimulation sessions. The findings of this study support a significant impact of neuromodulation of dorsolateral prefrontal cortex (DLPFC) on energy intake and food craving using tDCS. It is recommended that multisession bilateral stimulation of the DLPFC with the current intensity of 2 mA be used to reduce food craving.

Visual and auditory steady-state responses in attention-deficit/hyperactivity disorder

We designed a study to investigate the patterns of the steady-state visual evoked potential (SSVEP) and auditory steady-state response (ASSR) in adolescents with attention-deficit/hyperactivity disorder (ADHD) when performing a motor response inhibition task. Thirty 12- to 18-year-old adolescents with ADHD and 30 healthy control adolescents underwent an electroencephalogram (EEG) examination during steady-state stimuli when performing a stop-signal task. Then, we calculated the amplitude and phase of the steady-state responses in both visual and auditory modalities. Results showed that adolescents with ADHD had a significantly poorer performance in the stop-signal task during both visual and auditory stimuli. The SSVEP amplitude of the ADHD group was larger than that of the healthy control group in most regions of the brain, whereas the ASSR amplitude of the ADHD group was smaller than that of the healthy control group in some brain regions (e.g., right hemisphere). In conclusion, poorer task performance (especially inattention) and neurophysiological results in ADHD demonstrate a possible impairment in the interconnection of the association cortices in the parietal and temporal lobes and the prefrontal cortex. Also, the motor control problems in ADHD may arise from neural deficits in the frontoparietal and occipitoparietal systems and other brain structures such as cerebellum.

Transsexualism: A Different Viewpoint to Brain Changes

Transsexualism refers to a condition or belief which results in gender dysphoria in individuals and makes them insist that their biological gender is different from their psychological and experienced gender. Although the etiology of gender dysphoria (or transsexualism) is still unknown, different neuroimaging studies show that structural and functional changes of the brain result from this sexual incongruence. The question here is whether these reported changes form part of the etiology of transsexualism or themselves result from transsexualism culture, behaviors and lifestyle. Responding to this question can be more precise by consideration of cultural neuroscience concepts, particularly the culture–behavior–brain (CBB) loop model and the interactions between behavior, culture and brain. In this article, we first review the studies on the brain of transgender people and then we will discuss the validity of this claim based on the CBB loop model. In summary, transgender individuals experience change in lifestyle, context of beliefs and concepts and, as a result, their culture and behaviors. Given the close relationship and interaction between culture, behavior and brain, the individual’s brain adapts itself to the new condition (culture) and concepts and starts to alter its function and structure.

Epidemiology of psychiatric disorders in children and adolescents; in Tehran, 2017

OBJECTIVE This survey was conducted to investigate the prevalence of various psychiatric disorders among children and adolescents aged 6-18 years in urban areas of Tehran. METHODS In the study, which was done with random sampling method, 2095 children and adolescents in the range seniors aged 6-18 years, have been studied and based on Persian version of K-SADS-PL, we reviewed the psychiatric disorders related to them. RESULTS The overall prevalence of psychiatric disorders in children and adolescents was 28.2%. The most commonly diagnosed disorders were anxiety disorders (21.9%), followed by behavioral disorders (9.6%). CONCLUSION According to the results, 28.2% of the children and adolescents in Tehran province had psychiatric disorders, that is with increasing rate, compared with similar studies. Therefore, as a public health policy, the necessary tools for identifying, preventing and treating psychiatric disorders in children and adolescents should be considered in Tehran.