Gender Determines the Pattern of Correlation between Body Mass Index and Major Depressive Disorder among Children and Adolescents: Results from Iranian Children and Adolescents' Psychiatric Disorders Study.

Background: We aimed to determine the correlation of BMI with depression and to determine the role of gender in this association, in a large study sample. Methods: We used the data of participants in the Iranian Children and Adolescents' Psychiatric Disorders (IRCAP) Study, conducted in 2017. This study was a national community-based, cross-sectional study in which the urban and rural areas of all provinces of Iran were covered. Overall 30,532 children and adolescents, ages 6-18, were randomly selected with the stratified cluster sampling method. Results: Of a total of 30,532 participants, 25,321, whose BMI had been measured and who had been interviewed with Kiddie Schedule for Affective Disorders and Schizophrenia (K-SADS), entered the study (12,455 boys and 12,866 girls). We categorized the participants according to the national cutoff points for BMI classification. After controlling for age, father's and mother's job and education, and place of residence, the odds ratio (OR) of depression in underweight, healthy weight, and overweight boys compared with obese boys was 2.19 [95% confidence interval (95% CI): 1.00-4.81], 1.06 (95% CI: 0.73-1.55), and 0.80 (95% CI: 0.49-1.32), respectively. In the girls' subgroup, after controlling for the aforementioned covariates, the OR of depression in healthy weight, overweight, and obese participants compared with underweight subjects was 1.29 (95% CI: 0.52-3.19), 1.54 (95% CI: 0.59-3.98), and 1.79 (95% CI: 0.68-4.69), respectively. Conclusions: Underweight boys were more likely diagnosed with depression than normal weight and overweight boys. While in girls, the probability of depression increased by increased BMI.

Abnormalities of Alpha Activity in Frontocentral Region of the Brain as a Biomarker to Diagnose Adolescents With Bipolar Disorder.

Objectives. To investigate brain abnormalities in adolescents with new-onset bipolar disorder (BD) during acute hypomanic and depressive episodes using electroencephalogram (EEG) analysis and to derive a computer-based method for diagnosis of the disorder. Methods. EEG spectral power and entropy of 21 adolescents with BD (included 11 patients in the hypomanic episode and 10 patients in the depressive episode) and 18 healthy adolescents were compared. Moreover, using significant differences and K-nearest-neighbors (KNN) classifier, it was attempted to distinguish the BD adolescents from normal ones. Results. The BD adolescents had higher values of spectral power in all frequency bands, particularly in the frontocentral, mid-temporal, and right parietal regions. Also, spectral entropy had significantly increased in delta, alpha, and gamma frequency bands for BD. A high accuracy of 95.8% was achieved by all significant differences in the alpha band in discriminating adolescents with BD. The depressive state showed higher values of spectral power and entropy in low-frequency bands (delta and theta) compared to the hypomanic state. Conclusion. Based on BD symptoms, especially inattention, increased alpha power is a rational finding which is associated with thalamus dysfunction. Thus, it seems that EEG alpha oscillation is the main source of abnormality in BD. Furthermore, EEG slowing in the depressive episode is related to inhibition of electrical activity and reduced cognitive functions.