The Strengths and Difficulties Questionnaire (SDQ)

This study was a first attempt to examine the psychometric properties of the Strengths and Difficulties Questionnaire (SDQ) in Dutch youths. A large sample of normal children and adolescents (N = 562) and their parents completed the SDQ along with a number of other psychopathology measures. Factor analysis of the SDQ yielded five factors that were in keeping with the hypothesised subscales of hyperactivity-inattention, emotional symptoms, peer problems, conduct problems, and prosocial behaviour. Furthermore, internal consistency, test-retest stability, and parent-youth agreement of the various SDQ scales were acceptable. Finally, the concurrent validity of the SDQ was good: that is, its scores correlated in a theoretically meaningful way with other measures of psychopathology. It can be concluded that the psychometric properties of the parent- and self-report version of the SDQ were satisfactory in this Dutch community sample. Moreover, the current data provide further support for the utility of the SDQ as an index of psychopathological symptoms in youths. Accepted: 30 September 2002 Correspondence to Peter Muris, Ph. D.     

The Strengths and Difficulties Questionnaire among Finnish school-aged children and adolescents

 The emotional and behavioural problems of 7- to 15-year-old Finnish children and adolescents (n = 735) were assessed in a community population by a brief screening instrument, the Strengths and Difficulties Questionnaire (SDQ). The parent-, teacher- and self-reports of the SDQ were obtained. The results show that for the total scores, the inter-rater agreement between the pairs of reports was 0.38–0.44. The internal consistency in all three questionnaires was 0.71. Functioning above the 90th percentile of the SDQ total difficulties scores in parent-, teacher- and self-reports was strongly associated with help-seeking variables and problematic behaviour according to parents. The correlation of the parental SDQ total scores and the Child Behaviour Checklist total scores was 0.75 and the correlation of the self-report SDQ total scores with the Youth Self Report total scores was 0.71. The differences in sex, grade and informants of the SDQ total difficulties scores are reported. The study gives further evidence of the usefulness of the SDQ as a promising screening instrument for epidemiological research and clinical purposes. Accepted: 17 April 2000     

Comparing the German versions of the Strengths and Difficulties Questionnaire (SDQ-Deu) and the Child Behavior Checklist

 The Strengths and Difficulties Questionnaire (SDQ) is a brief behavioural screening questionnaire that can be completed in about 5 minutes by the parents and teachers of 4–16 year olds. The scores of the English version correlate well with those of the considerably longer Child Behavior Checklist (CBCL). The present study compares the German versions of the questionnaires. Both SDQ and CBCL were completed by the parents of 273 children drawn from psychiatric clinics (N = 163) and from a community sample (N = 110). The children from the community sample also filled in the SDQ self-report and the Youth Self Report (YSR). The children from the clinic sample received an ICD-10 diagnosis if applicable. Scores from the parent and self-rated SDQ and CBCL/YSR were highly correlated and equally able to distinguish between the community and clinic samples, with the SDQ showing significantly better results regarding the total scores. They were also equally able to distinguish between disorders within the clinic sample, the only significant difference being that the SDQ was better able to differentiate between children with and without hyperactivity-inattention. The study shows that like the English originals, the SDQ-Deu and the German CBCL are equally valid for most clinical and research purposes. Accepted: 22 February 2000     

Psychometric properties of a Swedish version of the “Strengths and Difficulties Questionnaire”

A new English instrument for screening mental health in children and adolescents, the Strengths and Difficulties Questionnaire (SDQ), was translated into Swedish and used for parental ratings of 900 children aged 6–10 years from the general population. The SDQ which comprises 25 items, divided into 5 subscales (prosocial, hyperactivity, emotional symptoms, conduct problems, and peer problems) was developed from the Rutter scales. An earlier English validation study has shown the two instruments to have equal ability to identify child psychiatric cases, but the SDQ also provides screening on empathy and prosocial behaviour which are aspects of child development emphasized in current child psychiatry. The design of the SDQ with both strengths` and difficulties` items supposedly increases acceptability of the instrument on behalf of informants and makes the questionnaire especially suitable for studies of general population where the majority of children are healthy. Our results, which are novel findings on the instrument, confirmed the postulated factor structure and showed significant gender-differences in results on the total scale, prosocial and hyperactivity subscales and on some of the single items. Moreover, our investigation showed that a Swedish translation of the parental version of the SDQ worked well. Accepted: 5 October 1998     

The strengths and difficulties questionnaire: A pilot study on the validity of the self-report version

 The self-report version of the Strengths and Difficulties Questionnaire (SDQ) was administered to two samples of 11–16 year olds: 83 young people in the community and 116 young people attending a mental health clinic. The questionnaire discriminated satisfactorily between the two samples. For example, the clinic mean for the total difficulties score was 1.4 standard deviations above the community mean, with clinic cases being over six times more likely to have a score in the abnormal range. The correlations between self-report SDQ scores and teacher or parent-rated SDQ scores compared favourably with the average cross-informant correlations in previous studies of a range of measures. The self-report SDQ appears promising and warrants further evaluation. Received: 19 August 1997 Accepted: 16 January 1998     

A natural history of hyperactivity and conduct problems: self-reported outcome

At the age of 16–18 years, outcome was prospectively assessed in a general population sample of four behavioural groups, defined at 6–7 year old: a pure pervasively hyperactive group (N=31), a mixed hyperactive conduct problem group (N=20), a pure conduct problem group (N=18) and a normal control group (N=29). The objective of the present paper is to describe outcome in those domains for which self-report is recognised as a valid source of information. Differential effects for hyperactivity and conduct problems on outcome were studied. It was found that early hyperactivity and conduct problems predicted different patterns of conduct problems in adolescence. Drug use in adolescence was not predicted by either type of behavioural problem in childhood. Overall social adjustment was worse in the hyperactive groups, whereas no differences in self-esteem were found. Hyperactivity was a strong predictor of relationships problems in adolescence. The results suggest that hyperactivity and conduct problems in childhood are differential predictors of outcome in adolescence. Accepted: 28 April 1999     

The development of the Chinese version of Impact of Event Scale – Revised (CIES-R)

Background: This is an exploratory study on the psychometric properties and normative data of the Chinese translation of the Impact of Event Scale – Revised (CIES-R). Methods: The original Impact of Event Scale – Revised was translated into Chinese and the comparability of content was verified through back-translation procedures. The study consisted of a sample of 116 patients from the Accident and Emergency Department. Results: The reliability of the Chinese version was verified. The validity of the Chinese version as a measure of psychological distress was supported by the positive correlations between the various subscale scores of CIES-R (i. e., Intrusion, Avoidance, and Hyperarousal) and General Health Questionnaire-20. However, the independence of the three subscales was not supported. Conclusions: The present result suggests that normative information for different age groups and clinical samples might be different. Further study with clinical sample and investigation of the relationship between CIES-R and other diagnostic measures of PTSD are discussed. Received: 22 August 2002 / Accepted: 13 September 2002 Correspondence to Kitty K. Wu     

Social Anxiety Scale for Adolescents (SAS-A): Measuring Social Anxiety Among Finnish Adolescents

The aim of this study was to investigate symptoms of social anxiety and the psychometric properties of the Social Anxiety Scale for Adolescents (SAS-A) among Finnish adolescents, 13–16 years of age. Study 1 (n = 867) examined the distribution of SAS-A scores according to gender and age, and the internal consistency and factor structure of the SAS-A. In a subsample (n = 563; Study 2) concurrent and discriminant validity of the SAS-A were examined relative to the Social Phobia Inventory and the Beck Depression Inventory. Test–retest stability was examined over a 30-month period by repeated measures every 6 months in another subsample (n = 377; Study 3). Results mostly revealed no gender differences in social anxiety, except that boys reported more general social avoidance and distress than girls. Older adolescents (14–16-year-olds) reported higher social anxiety than younger adolescents (12–13-year-olds). Internal consistency for the SAS-A was acceptable for both genders and for all three SAS-A subscales. Confirmatory factor analysis replicated the original 18-item three-factor structure of the SAS-A, accounting for 61% of the variance between items. Evidence for concurrent and discriminant validity was found. Test–retest stability over 6 months was satisfactory. Results support the reliability and validity of the Finnish adaptation of the SAS-A, and further indicate that gender differences in adolescents’ social anxiety may vary across Western countries.     

Appraisals of stress in child-rearing in Swedish mothers pre-schoolers with ADHD

Dutch self-report questionnaire for measuring parental: i) subjective stress, ii) global appraisal of the child-rearing situation, iii) attribution of child-rearing outcomes, and iv) expectation for help was translated into Swedish and applied to mothers of two groups of 3- to 7-year-olds: one with DSM-IV ADHD (n = 131) and one without DSM-IV ADHD (n = 131). The suggested factor structure of the original Dutch report was tested with confirmatory analysis on data from the mothers of children with ADHD [131]. There was no perfect fit to the data, but close enough to judge the factors as applicable to this sample. Factor reliability testing was performed. Results indicated good psychometric properties. Highly significant differences on all the measures in the four different sections (i) through (iv) were found between the ADHD group and the comparison group. The questionnaire is suggested to be useful in clinical work and research projects on problematic child-rearing situations.     

Does socioeconomic status predict course and outcome in patients with psychosis?

Background We examined the relationship between socioeconomic status (SES) and course and outcome of patients with psychosis. Two hypotheses were examined: a) patients with higher best-ever SES will have better course and outcome than those with lower best-ever SES, and b) patients with greater downward drift in SES will have poorer course and outcome than those with less downward drift. Method Data were drawn from the baseline and 2-year follow-up assessments of the UK700 Case Management Trial of 708 patients with severe psychosis. The indicators of SES used were occupational status and educational achievement. Drift in SES was defined as change from best-ever occupation to occupation at baseline. Results For the baseline data highly significant differences were found between best-ever groups and negative symptoms (non-manual vs. unemployed – coef −10.5, p=0.000, 95 % CIs 5.1–15.8), functioning (non-manual vs. unemployed – coef −0.6, p=0.000, 95 % CIs 0.3 to −0.8) and unmet needs (manual vs. unemployed – coef 0.5, p=0.004, 95 % CIs 0.2–0.9). No significant differences between best-ever groups were found for days in hospital, symptoms, perceived quality of life and dissatisfaction with services. Significant differences for clinical and social variables were found between drift and non-drift SES groups. There were no significant findings between educational groups and clinical and social variables. Conclusions Best-ever occupation, but not educational qualifications, appeared to predict prognosis in patients with severe psychosis. Downward drift in occupational status did not result in poorer illness course and outcome. Accepted: 3 August 2001     

Suicide in first- and second-generation immigrants in Sweden A comparative study

Background: Studies of suicide in first-generation immigrants have consistently shown higher rates compared to their country of origin. Little is known about the risk of suicide in second-generation immigrants and intercountry adoptees. The aim of this study was to investigate rates of suicide death in second-generation immigrants and intercountry adoptees in comparison with their parental generation and the majority population. Method: The study was based on multivariate analyses of register data on suicide death during 1990–98 in a Swedish national cohort of 2.7 million residents (10–68 years). Results: Second-generation immigrants tended to have higher odds than the first-generation immigrants compared to the majority population in all six minority groups studied. The Finnish minority had the highest and the Middle Easterners the lowest odds for suicide death in both generations of immigrants. The intercountry adoptees had very high odds for suicide death (adjusted OR: 5.0; 95 % CI 3.5–7.0). Conclusions: Second-generation immigrants are at greater risk for suicide death than their parental generation. Intercountry adoptees should be of particular concern in suicide prevention. Accepted: 10 April 2002     

Reassessment of ADHD in a historical cohort of children treated with stimulants in the period 1969–1989

The operational diagnostic criteria for ADHD or HKD were not at hand in Denmark before 1994, when WHO's International Classification of Diseases −10 (ICD–10) was introduced. The criteria for ADHD/HKD were well known at our clinic, but when treating children with stimulants the criteria used clinically prior to 1994 were less specific than today. The aims of this paper are to examine the prevalence of ADHD in a historical cohort of children treated with stimulants during the period 1969–1989 and to reassess a wide range of comorbid disorders and sociodemographic characteristics in order to compare aspects of the given treatment with the modern recommendations. At our clinic 208 children (183 boys) were given stimulants during the period 1969–1989. Case records on these probands were reassessed retrospectively for DSM-IV criteria regarding ADHD and comorbid disorders as well as for characteristics of stimulant treatment. Sixty-five percent met full criteria for an ADHD diagnosis. Including Subthreshold ADHD as many as 81 % of the cohort were re-diagnosed with ADHD. Prevalence rates of conduct problems and anxiety disorder were similar to previous prospective ADHD studies. The use of stimulants during the period 1969–1989 were in accord with modern guidelines. This cohort is comparable to other clinically based ADHD cohorts as regards inattentive, hyperactive/impulsive symptoms, comorbidity, impairment, gender differences, intelligence and socio-economic status (SES). Accepted: 27 April 2001     

Screening mental health problems during adolescence: Psychometric properties of the Spanish version of the Strengths and Difficulties Questionnaire

The main purpose of the present study was to test the psychometric properties of the Strength and Difficulties Questionnaire (SDQ), self-reported version, in Spanish adolescents, introducing a five-point Likert response scale. The sample consisted of 1474 adolescents with a mean age of 15.92 years (SD = 1.18). The level of internal consistency of the SDQ Total score was .75, ranging from .56 to .71 for the subscales. Results from exploratory factor analysis revealed a three-factor structure as the most satisfactory. Confirmatory factor analyses showed that the five-factor model (with modifications) displayed better goodness of-fit indices than the other hypothetical dimensional models tested. Furthermore, strong measurement invariance by age and partial measurement invariance by gender was supported. The study of the psychometric properties confirms that the Spanish version of the SDQ, self-reported form, is a useful tool for the screening of emotional and behavioural problems in adolescents.     

Australian data and psychometric properties of the Strengths and Difficulties Questionnaire

OBJECTIVE: We examine the Australian psychometric properties of the Strengths and Difficulties Questionnaire (SQD), a brief screening measure of behavioural and emotional problems in children and adolescents. METHOD: Using a large community sample (n = 1359) of young Australian children (4-9 years), we assessed the internal consistency, stability, and external validity of the parent-report SDQ. Normative data and cut-offs were also produced. RESULTS: Moderate to strong internal reliability was exhibited across all SDQ subscales, and support was found for the original five-factor structure of the measure. Adequate validity was evidenced in the relationship of these scales to one another, while correlations between the SDQ subscales, teacher ratings, and diagnostic interviews demonstrated sound external validity. SDQ total difficulties scores were associated with concurrent treatment status and scores over a 12-month period were stable. CONCLUSIONS: The current study of the SDQ with Australian children presents evidence of sound psychometric properties. Being the first study to empirically support the use of the SDQ in Australia, it is recommended that the youth and teacher-report forms of the measure receive similar attention in the future.     

Reliability and validity of a child-specific cross-cultural instrument for assessing posttraumatic stress disorder

 The Posttraumatic Stress Symptoms in Children (PTSS-C) was developed as a cross-cultural semi-structured interview to diagnose posttraumatic stress disorder (PTSD) and to identify PTSD-non-related posttraumatic stress symptoms in children after various traumatic experiences. The psychometric properties were studied in two different child populations in Iraqi Kurdistan (the survivors of the military operation “Anfal”, and the orphans), in a sample of Kurdistanian refugee children in Sweden, and in a comparison sample of Swedish children. The instrument yielded satisfactory internal consistency, high interrater agreement, and excellent validity on cross-validation with the Child Posttraumatic Stress Disorder Reaction Index (CPTSD-RI) and the Diagnostic Interview for Children and Adolescents (DICA) according to the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV). Accepted: 14 March 2000     

DSM-IV Conduct Disorder symptoms in adolescents as markers of registered criminality

A nationwide sample of 1,079 Norwegian adolescent psychiatric in-patients, 581 males and 498 females, were followed up after 11–33 (mean 23.2) years. On the basis of detailed records from index hospitalisation they were re-diagnosed and retrospectively scored on 14 of the 15 behaviour items listed as diagnostic criteria for conduct disorder in DSM-IV. The patient list was linked to the national criminal registry, and 48 % were found to have a criminal record. The ability of the 14 behaviour items to identify overall and specific kinds of registered criminality was investigated. In males, “stealing” was the strongest marker for overall and violent crime. “Having forced someone into sexual activity” was a strong marker for later sex offences. In females, “running away from home” was strongly associated with overall and violent registered criminality. ROC curves were constructed to test the sensitivity and specificity of the sum of conduct disorder behaviour items fulfilled in the identification of individuals with registered criminality. The area under the curve was 0.81 (95 % c. i. = 0.78–0.85) in males and 0.75 (95 % c. i. = 0.71–0.80) in females. A cut-off at 3 criteria fulfilled seemed optimal in males and somewhat high in females. Accepted: 17 May 2001     

Self-reported strengths and difficulties in a large Norwegian population 10–19 years

This study reports young people’s assessment of own problems and strengths from a Norwegian survey (n=29,631, age range 10–19), based on the self-report version of the Strengths and Difficulties Questionnaire (response rate 84.3%). Differences according to the age and gender are illuminated. Girls reported most emotional problems and boys most conduct and peer problems. Compared to other countries, Norwegian adolescents reported more hyperactive behaviour. Total problem scores were highest in early-adolescence for boys (Mean=10.8, SD=6.1), and for girls it is in late adolescence (Mean 11.3, SD=5.2). One third of the subjects reported at least minor perceived difficulties. All symptom scales were strongly associated with perceived difficulties, impact and burden to others (P<0.001) with significant gender and age effects. Impact scores were included in the estimate of possible caseness. Combining symptom scores and impact scores, 3.7% of the sample was defined as a high risk group, while 8.8% needed special attention from mental health services. The results also suggested that SDQ could be a valuable screening instrument for older adolescents.     

Scale properties of the Japanese version of the Strengths and Difficulties Questionnaire (SDQ): a study of infant and school children in community samples

The Strengths and Difficulties Questionnaire (SDQ) is a short screening instrument which addresses the positive and negative behavioral attributes of infants, children and adolescents. The SDQ is widely used to evaluate child developmental disabilities, psychological and psychiatric conditions or disorders in Japan. However, we did not have normative data for the Japanese version until now. To establish the community-based data and properties for the Japanese version, we collected and evaluated parent ratings of a total of 2899 Japanese children aged 4–12 years, including 1463 boys and 1436 girls. Statistical evaluation of psychometric properties included a factor analysis verifying the proposed scale structure, an assessment of scale homogeneities, and the determination of age, gender and relationship of each difficulties scale, or prosocial scale. The total difficulties score in boys (8.70 ± 5.03) was higher than in girls (7.86 ± 4.88). Based on the distributions of SDQ scores observed in the Japanese community sample, recommended bandings identifying normal, borderline, and abnormal (clinical ranges) were defined for each scale, and some gender difference was found in some difficulties and prosocial SDQ scores. After evaluating parent ratings obtained in a community-based sample, the Japanese SDQ was shown to possess favorable psychometric properties. Thus, the Japanese translation of this popular and versatile instrument seems to be approximately as reliable and useful as the original English questionnaire.     

Evaluating a Short Form of the Academic Competence Evaluation Scales: Expanded Examination of Psychometric Properties

The Academic Competence Evaluation Scales (ACES; DiPerna and Elliott in School Psychol Rev 31(3):293, 2002) is a 73-item teacher rating scale that assesses academic skills and enablers. The ACES Short Form (ASF) is a newly extracted 32-item short form of the ACES that has promising psychometric properties (Anthony and DiPerna in School Psychol Q 32(4):552, 2017; School Mental Health 10(3):314–321, 2018). The goals of this study were to examine the factor structure and extend the psychometric assessment of three subscales of the ASF (interpersonal skills, motivation, and engagement) with an independent sample. Participants were 193 students (63.2% White; 46.1% female) in grades K through 4, in the classrooms of 12 teachers. Teachers completed three subscales of the ACES and reported on student inattention, hyperactivity/impulsivity, social functioning, and academic functioning. We also obtained parent and peer assessments of student social functioning. Results corroborated the factor structure found by Anthony and DiPerna (School Mental Health 10(3):314–321, 2018) and the high internal consistency (α’s > .90; ω’s > .80) of the three subscales. In an extension of previous work, correlations with parent, peer, and teacher report on other measures provided evidence for convergent and divergent validity of the three ASF subscales. ASF scores also differed significantly for students with and without academic, behavioral, and social difficulties, in a manner similar to that of the ACES. These findings, along with those of Anthony and DiPerna (School Psychol Q 32(4):552, 2017; School Mental Health 10(3):314–321, 2018), provide evidence that the subscales of ASF, although substantially shorter than the respective subscales of the ACES, retain the strong psychometric properties and clinical utility of the full-length measure.     

Self-reported competencies and problems among Swedish adolescents: a normative study of the YSR. Youth Self Report

The aim of the study was to provide a standardisation of self-reported competencies and emotional/behavioural problems among Swedish adolescents, using the Youth Self-Report (YSR). The YSR was completed by 2522 adolescents aged 13–18 years, recruited from secondary and upper secondary schools in different regions in Sweden. The results showed that effects of gender and age were small but significant with girls scoring higher than boys on most problem scales, and 15- to 16-year-olds scoring higher than younger and older adolescents on the problem scales. Small effects were also found for residence as well as for parental SES. The correlations between internalising and externalising problems were 0.51 for boys and 0.49 for girls, whereas the correlation between competence and problem scores was low. We conclude that the individual variation in YSR-scores is much greater than can be attributed to factors such as gender, age, SES, or residential area. Consequently, the YSR has the potential to serve as an instrument for assessing individual adolescents' self-reported competencies and problems in Sweden. Given the almost orthogonal relation between self-reported competencies and problems, the competence scale is surprisingly little used in psychopathology research. Accepted: 10 January 2001