Study design and participants
An online survey was conducted between September 24, 2021, and October 19, 2021. Eligible participants were mothers of children (under 18) with ADHD that had been diagnosed by medical experts. The survey link was distributed to the participants by two peer groups for parents of children with developmental disabilities, a provider of after-school care services, and a support group for children with developmental disabilities. A checkbox was set up on the top page of the survey form to confirm that mothers of children with ADHD diagnosed by medical experts were the targets of the survey. Only those who clicked on this checkbox were allowed to participate in the survey. Of the 164 respondents who responded during the survey period, 149 were included in the analysis after excluding six respondents with incomplete data and nine who did not live with their children.
Survey instrument
Attributes, ADHD tendencies, ADHD child’s attributes and severity of ADHD symptoms, parenting stressors, and mental health were assessed.
Attributes
Attributes included age, education, marital status, occupation, living with a spouse, household income, medication status, number of children, and number of children with ADHD. The mothers’ medication use for mental health problems (antidepressants, anxiolytics, hypnotics) and ADHD (ADHD medications) were questioned. A list of the generic drug names of such medications approved in Japan was provided in the questionnaire.
ADHD tendencies
Part A of the Adult ADHD Self Report Scale (ASRS-v1.1) [24] was used to define ADHD tendencies. The ASRS is a validated scale to screen adults for ADHD. The tool comprises 18 items, with six items for screening (Part A) and 12 additional questions (Part B). Respondents are considered positive on the ASRS when they answer four or more Part A questions at the threshold level [24]. The ASRS Part A screening has a sensitivity of 68.7% and specificity of 99.5% [24]. Cronbach’s alpha coefficient of the ASRS Part A in the present study was 0.831. In this study, mothers who tested positive on the ASRS Part A screening were defined as having ADHD tendencies.
ADHD child’s attributes and severity of ADHD symptoms
The attributes of child with ADHD included age, sex, diagnosis of comorbid developmental disorders (ASD, LD, DCD, other), and severity of ADHD symptoms. If the respondents had more than two children with ADHD, they were asked to respond regarding the child with the highest burden. The Japanese version of the home form of the ADHD-RS [25] was used for the severity of ADHD symptoms. The total ADHD-RS score was defined as the severity of ADHD symptoms. A higher score indicated more severe ADHD symptoms. Cronbach’s alpha coefficient of the ADHD-RS in the present study was 0.878.
Parenting stressors
The Developmental Disorder Parenting Stressor Index (DDPSI) [26] was used for parenting stressors. The DDPSI is designed to measure stressors in parents of children with developmental disabilities and has an 18-item questionnaire composed of four factors: (1) difficulties in understanding the child and coping with the child’s needs, (2) anxiety about the child’s future and independence, (3) inadequate understanding of the childʼs disorder from others, and (4) conflicting emotions with regard to the childʼs disorder. A higher score indicated higher stress experienced by the respondents. Cronbach’s alpha coefficients of the four factors in the respondents were 0.721–0.868.
Mental health
The Japanese version of the Kessler 6-Item Psychological Distress Scale (K6) [27] was used. This scale is used in the Comprehensive Survey of Living Conditions conducted triennially by the Ministry of Health, Labour, and Welfare in approximately 300,000 Japanese households to investigate basic matters of national life, such as health, medical care, welfare, pension, and income. Cronbach’s alpha coefficient of K6 for the respondents was 0.866.
Statistical methods
The 149 respondents were divided into two groups according to the presence or absence of ADHD tendencies assessed by the ASRS Part A screening. Group comparisons were conducted for attributes, ADHD child’s attributes and severity of ADHD symptoms, parenting stressors, and mental health. A student’s t-test was used to compare quantitative variables, and Pearson's chi-square test or Fisher–Freeman–Halton test was used to compare qualitative variables.
We then analyzed the association between mental health (K6 scores) and the variables of attributes, ADHD child’s attributes and severity of ADHD symptoms, and parenting stressors in each group. Pearson’s correlation analysis was used for associations with quantitative variables. Student’s t-test, Welch’s t-test, or one-way analysis of variance was used for associations with qualitative variables.
SPSS Statistics version 27 for Mac was used for all statistical analyses, and the statistical significance level was set at 5%.