Major depressive disorder (MDD) is a global healthcare issue and one of the leading causes of disability. Machine learning combined with non-invasive electroencephalography (EEG) has recently been shown to have the potential to diagnose MDD. However, most of these studies analyzed small samples of participants recruited from a single source, raising serious concerns about the generalizability of these results in clinical practice. Thus, it has become critical to re-evaluate the efficacy of various common EEG features for MDD detection across large and diverse datasets. To address this issue, we collected resting-state EEG data from 400 participants across four medical centers and tested classification performance of four common EEG features: band power (BP), coherence, Higuchi’s fractal dimension, and Katz’s fractal dimension. Then, a sequential backward selection (SBS) method was used to determine the optimal subset. To overcome the large data variability due to an increased data size and multi-site EEG recordings, we introduced the conformal kernel (CK) transformation to further improve the MDD as compared with the healthy control (HC) classification performance of support vector machine (SVM). The results show that (1) coherence features account for 98% of the optimal feature subset; (2) the CK-SVM outperforms other classifiers such as K-nearest neighbors (K-NN), linear discriminant analysis (LDA), and SVM; (3) the combination of the optimal feature subset and CK-SVM achieves a high five-fold cross-validation accuracy of 91.07% on the training set (140 MDD and 140 HC) and 84.16% on the independent test set (60 MDD and 60 HC). The current results suggest that the coherence-based connectivity is a more reliable feature for achieving high and generalizable MDD detection performance in real-life clinical practice.

The circadian locomotor output cycles kaput (CLOCK) gene encodes protein regulation circadian rhythm and also plays some roles in neural transmitter systems including the dopamine system. Several lines of evidence implicate a relationship between attention-deficit hyperactivity disorder (ADHD), circadian rythmicity and sleeping disturbances. A recent study has reported that a polymorphism (rs1801260) at the 3'-untranslated region of the CLOCK gene is associated with adult ADHD.

Abstract  The objectives of the present study were to estimate the psychiatric comorbidity of Taiwanese heroin users seeking treatment and to identify the gender differences in psychiatric comorbidity and drug use behavior. Subjects were interviewed using a structured questionnaire on drug use behavior and the Mini International Neuropsychiatric Interview for psychiatric disorders. Of the subjects, 58.5% of the male and 62.5% of the female subjects had at least one non‐substance‐use axis I psychiatric disorder or antisocial personality disorder. Compared to male subjects, female subjects were younger, were less educated, had higher rates of unemployment and had earlier onset of illicit drug use. Female subjects were 11‐fold more likely than male subjects to exhibit suicidal behavior. Among heroin abusers in the present study, female subjects were more widely exposed to unfavorable social factors and had substantially higher incidence of suicidal behavior than male subjects. Drug treatment centers should be aware of these gender differences and pay particular attention to comorbid depressive disorders and suicidal behavior of female heroin abusers.

Objectives. The purposes of this study were to determine whether salivary levels of dehydroepiandrosterone (DHEA) and cortisol are associated with attention deficit hyperactivity disorder (ADHD) or correlated with performance on the Continuous Performance Test (CPT). Methods. Fifty ADHD patients and 50 age- and gender-matched controls aged between 6 and 12 years were included in this cross-sectional study. DHEA and cortisol levels were determined from saliva samples collected by the passive drool method at 08:00 h. ADHD patients subsequently performed a computerized Continuous Performance Test (CPT). ADHD symptoms were evaluated with the Swanson, Nolan, and Pelham, Version IV Scale for ADHD (SNAP-IV), completed by the patients' parents, and with the ADHD Rating Scale (ADHD-RS), administered by a child psychiatrist. Results. Saliva DHEA levels and DHEA/cortisol ratios differed significantly between ADHD patients and controls. Among ADHD patients, saliva DHEA levels and DHEA/cortisol ratios were independently correlated with composite scores of CPT distractibility and CPT impulsivity. Basal levels of cortisol were not significantly associated with ADHD. Conclusions. DHEA, but not the cortisol basal level, may be a biological laboratory marker for ADHD, particularly for performance on the CPT. Both the causal relationship between DHEA and ADHD and the role of DHEA in treating ADHD require further investigation.

Attention deficit hyperactivity disorder (ADHD) is a common and highly heritable disorder of childhood characterized by inattention, hyperactivity and impulsivity. Molecular genetic and pharmacological studies suggest the involvement of the dopaminergic, serotonergic and noradrenergic neurotransmitter systems in the pathogenesis of ADHD. Monoamine oxidase A (MAO-A) encodes an enzyme that degrades biogenic amines, including neurotransmitters such as norepinephrine, dopamine and serotonin. In this study we examined a 30 bp promoter variable number tandem repeat (VNTR) and a functional G/T single nucleotide polymorphism (SNP) at position 941 in exon 8 (941G/T) of MAO-A for association with ADHD in a Taiwanese sample of 212 ADHD probands. Within-family transmission disequilibrium test (TDT) was used to analyse association of MAO-A polymorphisms with ADHD in a Taiwanese population. A nominally significant association was found between the G-allele of 941G/T in MAO-A and ADHD (TDT: P = 0.034. OR = 1.57). Haplotype analysis identified increased transmission of a haplotype consisting of the 3-repeat allele of the promoter VNTR and the G-allele of the 941G/T SNP (P = 0.045) to ADHD cases which the strong association with the G-allele drove. These findings suggest the importance of the 941G/T MAO-A polymorphism in the development of ADHD in the Taiwanese population. These results replicate previously published findings in a Caucasian sample.