Attention deficit hyperactivity disorder (ADHD) for children is one of the behavioral disorders that affect the brain’s ability to control attention, impulsivity, and hyperactivity and its prevalence has increased over time. The cure for ADHD is still unknown and only early detection can improve the quality of life for children with ADHD. At the same time, children with ADHD often suffer from various comorbidities like autism spectrum disorder (ASD), major depressive disorder (MDD), etc. Various researchers developed computational tools to detect children with ADHD depending on handwriting text. Handwriting text-based systems are depending on a specific language that causes problems for non-native speakers of that language. Moreover, very few researchers considered other comorbidities such as ASD, MDD, etc., in their studies to detect ADHD for children. In this study, handwriting patterns or drawing is assumed as an aspect to identify/detect ADHD children who have ASD using machine learning (ML)-based approaches. We collected handwriting samples from 29 Japanese children (14 ADHD with coexisting ASD children and 15 healthy children) using a pen tablet. We asked each child to draw two patterns, namely zigzag lines and periodic lines (PL) on a pen tablet and repeated them three times. We extracted 30 statistical features from raw datasets and these features were analyzed using sequential forward floating search (SFFS) and selected the best combinations or subsets of features. Finally, these selected features were fed into seven ML-based algorithms for detecting ADHD with coexisting ASD children. These classifiers were trained with leave-one-out cross-validation and evaluated their performances using accuracy, recall, precision, f1-score, and area under the curve (AUC). The experimental results illustrated that the highest performance scores (accuracy: 93.10%; recall: 90.48%; precision: 95.00%; f1-score: 92.68%; and AUC: 0.930) were achieved by the RF-based classifier for the PL predict task. This study will be helpful and provide evidence of the possibility of classifying ADHD children having ASD and healthy children based on their handwriting patterns.

Attention deficit hyperactivity disorder (ADHD) for children is one of the most common neurodevelopmental disorders and its prevalence has increased globally. Children with ADHD are faced with various difficulties, including inattention, impulsivity, and hyperactivity. Therefore, it is important to use an early detection system that is simple, non-invasive, and automated. Children with ADHD also suffer from other coexisting one or more disorders, including major depressive disorder (MDD), autism spectrum disorder (ASD), etc and it creates more challenges to detect ADHD children. Very few researchers considered such kinds of these comorbidities in their studies to detect ADHD for children. In this work, we proposed a deep learning (DL)-based algorithm to identify ADHD children with coexisting ASD. Functional near-infrared spectroscopy (fNIRs) signals from thirteen ADHD children who have coexisting ASD and fifteen typically developing (TD) children were recorded during the drawing of handwriting patterns. We asked each child to draw periodic lines (PL) and zigzag lines (ZL) under the predict and trace condition and repeated them three times. Finally, a hybrid approach was designed by combining convolutional neural networks (CNN) and bidirectional long short-time memory (Bi-LSTM) to determine children with ADHD who have ASD. The experimental results showed that our proposed hybrid approach could determine ADHD children with coexisting ASD with a classification accuracy of 94.0%, a sensitivity of 89.7%, specificity of 97.8%, f1-score of 93.3%, and AUC of 0.938, respectively, for the PL predict task.

The classification of different age groups, such as adult and child, based on handwriting is very important due to its various applications in many different fields. In forensics, handwriting classification helps investigators focus on a certain category of writers. This paper aimed to propose a machine-learning (ML)-based approach for automatically classifying people as adults or children based on their handwritten data. This study utilized two types of handwritten databases: handwritten text and handwritten pattern, which were collected using a pen tablet. The handwritten text database had 57 subjects (adult: 26 vs. child: 31). Each subject (adult or child) wrote the same 30 words using Japanese hiragana characters. The handwritten pattern database had 81 subjects (adult: 42 and child: 39). Each subject (adult or child) drew four different lines as zigzag lines (trace condition and predict condition), and periodic lines (trace condition and predict condition) and repeated these line tasks three times. Handwriting classification of adult and child is performed in three steps: (i) feature extraction; (ii) feature selection; and (iii) classification. We extracted 30 features from both handwritten text and handwritten pattern datasets. The most efficient features were selected using sequential forward floating selection (SFFS) method and the optimal parameters were selected. Then two ML-based approaches, namely, support vector machine (SVM) and random forest (RF) were applied to classify adult and child. Our findings showed that RF produced up to 93.5% accuracy for handwritten text and 89.8% accuracy for handwritten pattern databases. We hope that this study will provide the evidence of the possibility of classifying adult and child based on handwriting text and handwriting pattern data.

Attention-deficit/hyperactivity disorder (ADHD) is a neurodevelopmental disorder characterized by the symptoms of inattention, hyperactivity, and impulsivity that significantly affect daily functioning. It is usually 1st diagnosed in childhood and often lasts into adulthood. Various researchers introduced different statistical tools to identify children with ADHD based on phonotype, vision, and image-based data. The main causes of children with ADHD are still unknown and its diagnostic accuracy rate remains low. There is still some scopes to establish valid biomarkers for ADHD and improve classification accuracy, which will help for children enhance their quality of life. This study aimed to establish and determine potential biomarkers for children with ADHD and then proposed a machine learning (ML)-based ADHD detection system. A multicenter approach was employed to collect Reverse Stroop Task (RST) data, including age, behavioral, and physiological indicators from 72 children with ADHD (aged 6-13 years) and 171 typically developing (TD) children. Moreover, we also collected the signal information from each subject using functional near-infrared spectroscopy (fNIRs) and quantified the change in prefrontal cortex oxygenated hemoglobin during RST. At the same time, we also computed the mean signal for every channel during the last 20 seconds of RST. We selected 70% of the dataset as a training set (ADHD: 51 and TD: 120) and the remaining dataset was used as a testing set (ADHD: 21 and TD: 51). To determine the potential biomarkers for ADHD, we employed independent t-test ( p < 0.05) on training data that contained behavioral, physiological, and signal indicators. These significant biomarkers were used to train six ML-based approaches, including support vector machine, k-nearest neighbors, logistic regression, neural network, linear discriminate analysis and random forest (RF) with 10-fold cross-validation and repeated 10 times for selecting the optimum value of hyperparameters using the classification accuracy. The trained ML-based approaches were used to predict children with ADHD and validate their performance on the testing data. The experimental results showed that the RF-based model obtained a classification accuracy of 91.67%, sensitivity of 95.92%, specificity of 82.61%, precision of 92.16%, F1-Score of 94.00%, Cohen’s Kappa of 80.38%, geometric mean of 89.02%, positive likelihood ratio of 5.51%, negative likelihood ratio of 0.05%, and area under the curve of 0.955. Our proposed system can be used for the diagnosis of children with ADHD.