Psychosocial problems such as behavioral and emotional complications are highly prevalent in children and adolescents [1–3]. Studies have demonstrated that approximately 3%-18% of children and about 10–25% of adolescents suffer from psychopathological problems [1–5]. Although no comprehensive study has investigated the prevalence of psychosocial problems in Iran, its frequency has been reported to be 6.4–17.9% in adolescents [6–10]. Mohammadi et al. (2013) assessed the prevalence of psychological problems in adolescents (11- to 17-year-olds) in 5 provinces of Iran using the Strengths and Difficulties Questionnaire (SDQ), which was reported equal to 7.6–28.4% [11].
Despite relatively high prevalence rates of mental health problems, only a limited number of people suffering mental health problems seek mental health services at psychiatrist or psychologist offices and clinics. Furthermore, many mental health problems show subtle signs at earlier ages and may be missed or overseen without valid and reliable screening or diagnostic tools. Therefore, access to an instrument for detecting and measuring emotional and behavioral problems, especially in children and adolescents, is extremely important and necessary [12, 13] for early detection and early intervention purposes. It can also be helpful to clinicians in treatment planning [14, 15] and in estimating treatment outcomes.
SDQ is considered as an important screening instrument for child and adolescent psychiatric disorders in different countries [16–18]. SDQ scores have shown correlation with other measures of psychopathology in a significant way [19]. The early detection of the signs of psychosocial or socio-emotional developmental delays and disorders, followed by early intervention, along with paying attention to the early stages of development is important. Such actions can provide remarkable benefits with respect to mental health, overall wellbeing, and general child development. Valid and reliable screening instruments are necessary for the early detection of subtle developmental delays which are hardly recognizable otherwise.
The SDQ is a relatively short and user-friendly screening instrument. It is among the most widely applied tools for detecting the signs of emotional and behavioral disorders (“difficulties”), as well as assessing prosocial behaviors (“strengths”) in children aged 3–16 years [12, 17, 20]. This instrument was originally developed based on Rutter’s questionnaires and was later updated by Goodman, who added some items to the concentration, peer relationship problems, and prosocial behavior subscales of it. The improved questionnaire may be used on many children, particularly if focusing on children's strengths and weaknesses increases parental compliance [12, 21]. The “self-report”, “teacher-report” and “parent-report” versions of the SDQ are available. Adolescents aged 11–16 years and the parents and teachers of children aged 3 to 16 years, can complete the above-mentioned questionnaires, respectively, and report the difficulties and strengths. Previous studies have suggested that all three versions of the questionnaire are acceptable, reliable and valid [15, 20, 22–24]. The SDQ has 5 subscales, including emotional symptoms, conduct problems, hyperactivity/inattention, peer relationship problems, and prosocial behavior. Each of these subscales consists of 5 items. The first 4 subscales provide a “total difficulties” score, whereas the prosocial behavior scale independently reflects information on strengths. The SDQ has 5 subscales; 4 of which assess “difficulties”, as follows: emotional symptoms (e.g., fears), conduct problems (e.g., lies or cheats), hyperactivity/inattention (e.g., restlessness, hyperactivity), and peer relationship problems (e.g., picked on or bullied by other children). One subscale assesses prosocial behavior or “strengths” (e.g., being considerate of others’ feelings). Several studies have supported the 5-factor solution for the SDQ structure [25–30] and many others have not [27, 29, 31–33]However, the tool is still being used in the 5-subscale form by many researchers and clinicians worldwide. Scoring is based on the guideline provided at the SDQ website [34]. The total “difficulties”’ score is determined by computing the sum of scores acquired in the 4 related subscales. The obtainable minimum and maximum total scores for the “difficulties” sections are 0 and 40, respectively. For each of the 5 scales, the score can range from 0 to 10 if all items are completed [34]. Higher achieved scores in the 4 subscales assessing “difficulties” indicate the higher levels of difficulties, and worse emotional symptoms and behavioral status, consequently. Moreover, in the prosocial behavior subscale, higher scores indicate the higher levels of strengths or better emotional and behavioral symptoms. The SDQ has been translated into more than 40 languages and applied to assess the behavioral disorders in children and adolescents in various countries around the world [17, 19, 20, 22, 24, 35–37].
Although there have been previous attempts to validate the Persian self-report version of the SDQ in the Iranian population in two different studies conducted by Alavi et al [38] and Ghanizadeh et al. [39], some short-comings or differences regarding the methodology and implementation strategies, as well as statistical methods, brought about the need to reassess the psychometric properties of this tool once again in a representative sample of healthy Iranian young adolescents using sound methodology and statistical analyses, in order to provide newer and trustworthy results. For example, although Alavi et al. conducted their study on a large population of adolescents in Tehran city, recruited from 22 clusters, there are ambiguities regarding the sampling method. We do not know whether adolescents were recruited from their homes or from other settings, and if the former is true, which is the most likely possibility, how was it possible to acquire the informed consent of parents and adolescents themselves and to complete the questionnaire, all in a one-and-first-time visit at the door? In addition, examiners were employed for completing a questionnaire which was supposed to be a self-report questionnaire. This may have caused under-reporting of “problems” as well as over-reporting of “pro-social behavior” by the adolescents at the presence of a stranger at the door, asking for prompt replies to sometimes-uneasy questions regarding their behaviors. Moreover, the psychometric evaluation of this tool by Alavi et al. has been limited to assessing the Cronbach’s alpha coefficient, Pearson’s coefficient for the correlation between each subscale score with the total score, as well as comparing the 90th percentile cut-off point with that of Goodman’s study. In addition, regardless of the possible methodological shortcomings and differences between Alavi’s study and the present study, Alavi’s study was conducted in the year 2007 (and reported in the year 2009), when Iran had a population of 70 million people, 20% of which were under 20 years old. It is noteworthy that the Iranian population in the year 2015 (the year the latest Census was carried out in Iran) has risen to 80 million, with 45% under 20, and as Alavi et al. have correctly stated themselves (29), the “rapid pace of cultural changes in Iran and the ongoing shifts in the socio-cultural behaviors” raise the need for re-evaluation of the validity and reliability of the scores of a tool such as the SDQ, which is supposed to assess such behaviors in the ever-changing young adolescent population in Iran.
In the study conducted by Ghanizadeh et al., the target population was children and adolescents living in Shiraz city. Shiraz city is an important Iranian city in terms of historical as well as artistic roots. However, the population living in Shiraz is about 0.35 of that living in Tehran, Moreover, it is not comparable to Tehran city in terms of cultural diversity which is a dominant characteristic of Tehran due to the rather high rate of on-going migration to it from other cities and villages, which makes Tehran a miniature reflection of almost all the different socio-economic and cultural diversities present in the country. In addition, Ghanizadeh’s study was reported in 2007 and conducted earlier, which has not been mentioned in the article. So, just like Alavi’s study, the results are difficult to be trusted and relied on after more than 12 years.
In terms of methodology, there are also short-comings in Ghanizadeh’s study. The population recruited from schools was only those in primary schools, that is, those under 11 years old. Among 330 adolescents aged 11 to 18 years who participated in the study, 155 (almost half) were recruited from only one psychiatric clinic, with no reported criteria excluding those with diagnosed psychopathologies. The authors have themselves acknowledged this limitation. It has not been clearly stated how and where the rest of this age group were recruited. Thus, this adolescent population is far from representative of normal Iranian adolescents.
Moreover, in statistical terms, the Cronbach’s alpha coefficient and the correlation between items and subscale scores were the only psychometric analyses for which data was reported. The authors have claimed that EFA as well as CFA have been performed, resulting in a 3-factor solution for the tool, however data in terms of relevant tables, graphs or diagrams have not been provided.
So an urgent need for conducting another study aiming at determining the psychometric properties of the Persian self-report version of the SDQ was felt. In conducting the study, we aimed to answer three questions: (1) Are the scores of the Persian version of the SDQ (P-SDQ) reliable (in terms of internal consistency assessed by the Cronbach’s alpha coefficient) in the present Iranian young adolescent population? (2) Are all sub-scale scores of the P-SDQ reliable and have the best fit? (3) Are P-SDQ scores valid according to Confirmatory Factor Analysis (CFA)?