Wolfgang Woerner

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

Abstract 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.

Normative data and scale properties of the German parent SDQ.

Abstract.Background and objectives:The Strengths and Difficulties Questionnaire (SDQ) is a short assessment instrument which addresses positive and negative behavioural attributes of children and adolescents and generates scores for clinically relevant aspects. Although this brief questionnaire has been widely used in Germany to gather information from parents, teachers, and older children themselves, normative results obtained with the German version have not yet been reported to the international scientific community. To allow comparisons with SDQ findings in other countries, normative data for the German parentrated form as well as a communitybased evaluation of scale properties are summarised and complemented by results obtained in a number of clinical samples.Methods:Parent ratings were collected for a community-based sample of 930 children and adolescents aged between 6 and 16 years, in which both genders and all age levels were equally represented. Statistical evaluation of psychometric properties included a factor analysis verifying the proposed scale structure, assessment of scale homogeneities, and determination of age, gender and social class effects. Based on the distributions of SDQ scores observed in this normative sample, recommended bandings identifying normal, borderline, and clinical ranges were defined for each scale.Results:Exact replication of the original scale structure, satisfactory internal reliabilities, and observation of the expected associations with age and gender confirmed the equivalence of the German SDQ parent questionnaire with the English original. Differences between community-based results and clinical groups provided descriptive evidence of a dramatic impact of clinically defined psychiatric status on SDQ scores.Conclusions:After evaluating parent ratings obtained in a community-based sample, the German SDQ was shown to possess favourable psychometric properties. Thus, the German translation of this popular and versatile instrument seems to be a similarly reliable and useful assessment tool as the original English questionnaire.

Evaluation of the self-reported SDQ in a clinical setting: do self-reports tell us more than ratings by adult informants?

Abstract.Objectives:The aim of this study was to evaluate the German self-reported Strengths and Difficulties Questionnaire (SDQ) in a clinical setting. We also investigated whether this additional information gathered directly from older children and adolescents improves the prediction of clinical status when external ratings from their parents and/or teachers are already available.Methods:SDQ self-reports were collected from 214 in- and outpatients (81 girls and 133 boys) aged 11 to 17 years who were seen at the department of child and adolescent psychiatry of the University of Göttingen. Results obtained with the self-rated questionnaire were compared with the parent and teacher SDQs, corresponding CBCL/YSR scores, and the clinical diagnostic classification. Finally, the additional diagnostic benefits of the self-reports were examined.Results:The scales of the SDQ self-report proved to be sufficiently homogeneous, and acceptable correlations were found with the equivalent parent and teacher ratings. The self-rated version of the SDQ demonstrated good validity with respect to the differentiation between clinically defined cases and non-cases and in detecting various subcategories of psychiatric disorders within the clinic sample. SDQ self-reports significantly contributed to the prediction of diagnostic status, specifically if only parent or teacher ratings were available.Conclusions:The self-rated version of the SDQ was shown to be a reliable and valid method for the assessment of behavioural problems in children and adolescents. In the absence of adult informant reports from parents and teachers, the diagnostic value of self-ratings was also demonstrated.

Validation of the parent and teacher SDQ in a clinical sample.

Abstract.Objectives:This study examines whether the German translation of the Strengths and Difficulties Questionnaire (SDQ) is a reliable and valid screening instrument and whether it is as effective a tool for clinical diagnostics and scientific applications as the CBCL/TRF.Methods:We examined 543 children and adolescents (147 girls and 396 boys) with ages ranging from 5 to 17 years and correlated the results of the parent and teacher SDQ as well as the CBCL/TRF with clinical diagnoses. Furthermore, the adequacy of the scale structure of the SDQ was tested using confirmatory and exploratory factor analyses.Results:It was demonstrated that the scales of the parent and teacher versions were sufficiently homogeneous (0.72–0.83). Correlations between SDQ scales and corresponding CBCL/TRF scales showed a high degree of congruence, while an exact replication of the original SDQ scale structure could also be achieved. Parent and teacher versions of both questionnaires presented with good validity, not only with regard to the discrimination between child psychiatric patients and a representative community sample, but also in the identification of different categories of disorders within the clinical sample.Conclusion:The parent and teacher SDQs proved to be valid and helpful questionnaires for use in the framework of a multi-dimensional behavioural assessment, and appear to be well suited for screening purposes, longitudinal monitoring of therapeutic effects, and scientific research purposes.

Normierung und Evaluation der deutschen Elternversion des Strengths and Difficulties Questionnaire (SDQ): Ergebnisse einer repräsentativen Felderhebung

OBJECTIVE The (SDQ) is a short questionnaire which addresses positive and negative behavioural attributes of children or adolescents. Being rated by parents or teachers, or as an equivalent self-report version, the 25 SDQ items were designed to include both strengths and difficulties. Although several reports have demonstrated the validity of the German SDQ, normative data have not yet been established. METHODS In a nationwide representative field study, parent ratings were completed for 930 children and adolescents aged between 6 and 16 years. Following verification of the scale structure by factor analysis, the observed distributions of scores were used to define normal, borderline, and abnormal score ranges. Possible effects of gender, age, and social class were also investigated. RESULTS Factor analysis yielded an exact replication of the original scales. Several associations with gender, age, and social status attained statistical significance, but cut-off scores for the five subscales remained stable in different subgroups. Age- and sex-specific bandings for the total problem score reflected small differences between homogeneous subgroups. CONCLUSIONS After replication and confirming the original scale factors, the availability of normative data further enhances the diagnostic value of the SDQ and facilitates future validation studies. Present evidence suggests that the SDQ may serve as a useful and economical screening measure, and in many other clinical and research settings.Zusammenfassung: Fragestellung: Der Strengths and Difficulties Questionnaire (SDQ) ist ein kurzer Fragebogen zu Verhaltensauffalligkeiten und -starken bei Kindern und Jugendlichen, der in Eltern- u...

The Strengths and Difficulties Questionnaire overseas: evaluations and applications of the SDQ beyond Europe.

Abstract.Background:During the few years that have passed since it became available, the Strengths and Difficulties Questionnaire (SDQ) has been extensively evaluated and widely applied to assess behaviour disorders of children and adolescents in European countries. In contrast, relatively few reports have published SDQ results obtained in other parts of the world, although its briefness and availability in over 40 languages make this instrument particularly attractive for international collaborations and cross-cultural comparisons concerning clinical and epidemiological issues.Objectives:This initial overview summarises some of these non-European experiences with the SDQ by presenting a selection of projects that have either psychometrically evaluated this novel questionnaire, applied it to screen for behaviour disorders, or employed its parent-, teacher- or self-rated versions as research tools. Since a large part of the mentioned studies are ongoing or have only recently been completed, much of the work reported here is still unpublished.Conclusions:Across a huge variety of cultures and languages, experience gained with the SDQ in other continents has supported European evidence of good psychometric properties and clinical utility of this questionnaire. Since worldwide usage of the SDQ can be expected to increase in the future, more international coordination is encouraged, in order to fully exploit the promising potentials of this versatile assessment tool and systematically investigate cross-cultural differences and similarities in child and adolescent behaviour.

Abnormal early stages of task stimulus processing in children with attention-deficit hyperactivity disorder – evidence from event-related gamma oscillations

OBJECTIVES Attention-related differences in early stages of stimulus processing were assessed in healthy controls and children with attention-deficit hyperactivity disorder (ADHD) by analyzing phase-locked gamma band (31-63 Hz) responses to auditory stimuli in a selective-attention task. METHODS A total of 28 children aged 9-12 years (ADHD and matched healthy controls) pressed a button in response to each target stimulus presented at the attended side (right or left). Auditory gamma band responses (GBRs) within 0-120 ms were analyzed at 8 electrodes with wavelet transform. Effects of attended channel, stimulus type, and group were evaluated for GBR power and phase-locking. RESULTS For both groups, GBRs had a frontal-central distribution, were significantly larger and more strongly phase-locked to target than to non-target stimuli, and did not differentiate the attended from the unattended channel. ADHD children produced larger and more strongly phase-locked GBRs than controls only to right-side stimuli, irrespective of whether these were the attended or the ignored stimuli. CONCLUSIONS The association between auditory GBR and motor task stimulus in children suggests that phase-locked gamma oscillations may reflect processes of sensory-motor integration. ADHD-related deviations of GBRs indicate that early mechanisms of auditory stimulus processing are altered in ADHD, presumably as a result of impaired motor inhibition.

Disturbed sleep in children with Tourette syndrome: A polysomnographic study

OBJECTIVE To evaluate objective data on sleep quantity/quality and motor activity during night sleep in children with Tourette syndrome (TS). METHOD Polysomnography of 17 unmedicated TS children (ages: 7;11-15;5, mean: 11;10 years) without comorbid attention-deficit hyperactivity disorder (ADHD) was compared with 16 age-, sex- and IQ-matched healthy controls. Sleep analyses according to the procedure of Rechtschaffen and Kales were supplemented by counting epochs with short arousal-related movements (<or=15 s), thus allowing to calculate correlations between motor activity and sleep parameters. RESULTS Children with TS demonstrated changes in sleep parameters, including longer sleep period time, longer sleep latency, reduced sleep efficiency, and prolonged wakefulness after sleep onset. Their sleep profiles showed significantly more time awake and less sleep stage II. However, REM sleep variables, slow-wave sleep, and number of sleep stage changes were unaffected. Movement time was similar in both groups, but epochs with short arousal-related movements were increased in TS. Further analyses showed no significant correlations between sleep parameters and nighttime nontic movements, level of psychopathology or tic severity during daytime. Periodic limb movements during sleep (PLMS) were only seen in one TS patient (low PLMS index of 7.8/h). CONCLUSIONS Children with TS have disturbed sleep quality with increased arousal phenomena, which both may be intrinsic to the disorder and might trigger tics and other behavioral problems during daytime. This indicates the need for sleep evaluation in patients with TS.

Developmental event‐related gamma oscillations: effects of auditory attention

This study describes maturational changes in topographical patterns, stability, and functional reactivity of auditory gamma band (31–63 Hz) responses (GBRs) as brain electrical correlates relevant for cognitive development during childhood. GBRs of 114 healthy children from 9 to 16 years were elicited in an auditory focused attention task requiring motor responding to targets, and analyzed by means of the wavelet transform (WT). The effects of age and task variables (attended side and stimulus type relevance) were examined for GBR power and phase‐locking within 120 ms after stimulation. Similar to the spontaneous gamma band power, the power and phase‐synchronization of GBRs did not depend on the age. However, the functional reactivity of GBRs at specific locations changed in the course of development. In 9–12‐year‐old children, GBRs at frontal locations were larger and better synchronized to target than to nontarget stimulus type, and were larger over the left hemisphere (contralateral to the responding hand), thus manifesting sensitivity to external stimulus features and motor task. In 13–16‐year‐old adolescents, GBRs at parietal sites were enhanced by active attending to the side of stimulation, thus being associated with a maintenance of attentional focus to stimulus location. The results indicate that (i) specific aspects of task‐stimulus processing engage distinct spatially localized gamma networks at functionally relevant areas, and (ii) the neuronal substrates of gamma band networks and the ability to synchronize them in relation to task‐specific processes are available in all age groups from 9 to 16 years. However, the mode and efficiency with which gamma networks can be entrained depends on the age. This age‐dependent reactivity of GBRs to different task variables may reflect a transition in processing strategies emerging at approximately 12–13 years in relation to the maturation of cognitive and executive brain functions.

Frontocortical activity in children with comorbidity of tic disorder and attention-deficit hyperactivity disorder

Comorbidity of tic disorder (TD) and attention-deficit hyperactivity disorder (ADHD) in children is common but not fully understood. Thus we investigated the effect of TD and ADHD on the amplitude of the postimperative negative variation (PINV) in children with combined tic + hyperactivity symptoms (TD + HA). PINV was chosen as an indicator of frontal lobe functioning that is closely related to self-regulation of behavior. PINVs of four groups of children (healthy controls, pure TD, pure ADHD, and combined TD + HA; total number 43) were elicited in an auditory warned reaction task in three conditions (control = CC, loss-of-control = LoCC, and lack-of-control = LaCC) at midfrontal (Fz) and midcentral (Cz) leads of the scalp. Effects of TD and ADHD were revealed only in the noncontrol conditions, being independent in the LaCC, but interactive in the LoCC. Thus, the additive model of psychopathological classification concerning the comorbidity of TD and ADHD was only partially supported by the observed pattern of psychophysiological results.