East Asian Arch Psychiatry 2016;26:141-7

THEME PAPER

Ms Janice Y. N. Chan, BA, MPhil, Department of Psychiatry, The Chinese University of Hong Kong, Hong Kong SAR, China.
Prof. Kelly Y. C. Lai, MB, BS, MRCPsych, FHKAM (Psych), FHKCPsych, Department of Psychiatry, Chinese University of Hong Kong, Hong Kong SAR, China.

Address for correspondence: Prof. Kelly Y. C. Lai, Department of Psychiatry, The Chinese University of Hong Kong, Shatin, Hong Kong SAR, China.

Email: kellylai@cuhk.edu.hk

Submitted: 7 September 2015; Accepted: 1 February 2016

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Introduction

Autism spectrum disorders (ASD) are complex neurodevelopmental disorders characterised by impaired social communication skills and repetitive, stereotyped behaviours.¹ These core deficits are frequently associated with a broad range of challenging behaviours including temper tantrums, self-injury, aggression, and sensory hyper- or hypo-sensitivity. Prevalence estimates suggest an increasing trend: approximately 1 in 68 children are now thought to be affected.² This means that the number of families and siblings living with children with ASD has also significantly increased.

Although increased parental stress in looking after a child with ASD is well recognised, recent literature has drawn attention to the need to understand the adjustment of their typically developing siblings. Not least because factors such as parental stress can impact on the psychological health of typically developing children, siblings may also be directly affected by the experience of living with a child with ASD. Nevertheless, a review of 12 studies published between 1997 and 2008 by Meadan et al,³ as well as studies subsequent to the review^4-7, found results to be inconsistent and inconclusive. While some studies suggested no significant impact, others found an increase in internalising and externalising problems, as well as peer relationship difficulties. Methodological differences across studies could certainly be one reason for the inconsistent findings, as studies have generally suffered from small sample size; measures, informants and comparison groups are also different; and the characteristics of the autistic proband were seldom described.³

Mixed findings may also reflect the complex nature of the array of factors that interact to influence sibling adjustment. Several factors having been studied included sibling’s age and gender,^8-10 birth order,^9,11 severity of the ASD, and patterns of behaviour of the child with ASD,^12-14 but no clear associations have been found. Bauminger and Yirmiya¹⁵ proposed a diathesis-stress model and suggested that it is the interaction between genetic and environmental risk factors that affect sibling adjustment. More specifically, it postulates that the genetic basis of ASD may have placed siblings at increased risk of having subthreshold symptoms of autism (often referred to as ‘broad autism phenotype’ [BAP]), which, under stressful situations such as the presence of behavioural problems in the child with ASD or adverse family situations, increases sibling vulnerability to adjustment problems.^9,10,12,16

Most of the studies to date have come from the western world. Only a handful have been carried out among Chinese populations. Gau et al¹⁷ studied 115 Taiwanese families’ adjustment to having a child with ASD, and found siblings to have a small increase in internalising and externalising scores when compared with those without a sibling with ASD. A qualitative study that involved 5 families from Singapore¹⁸ found that children coped differently to having a sibling with ASD — some were empathetic and accommodating, while others became resentful and non-compliant. The data also evidenced “double-standard parenting” — mothers were more lax towards the misbehaviour of the child with ASD so siblings complained about unfair treatment in the family. An unpublished thesis from Hong Kong comparing the adjustment of 3 groups of siblings — siblings of children with autism, learning disability, or typical development — found no significant difference in internalising and externalising problems among the 3 groups, even though the siblings of the 2 handicapped groups experienced a higher level of stress.¹⁹ With such a small number of studies involving Chinese families, it is not possible to conclude if sibling adjustment is affected. At the same time, cultural differences between western and Chinese societies mean it cannot be assumed that western findings are applicable among Chinese families. The Confucius tradition of the Chinese culture — with its emphasis on filial piety, forgoing of self-interest for the benefit of the family and harmony, and one’s duty to the care of family members — could make the subjective experience of living with a sibling with ASD very different to that of the West, and consequently influence sibling adjustment.

Many of the children with ASD in Hong Kong are known to child mental health services. Mental health services are grossly under-resourced and the focus of care is typically on the child with ASD so sibling adjustment is seldom brought up for discussion. With an increasing awareness that sibling adjustment has, until recently, been neglected, there is now a recognised need to better understand sibling experience, and explore this in a Chinese population. This will help to understand the potential risks for the adjustment of siblings and the services that need to be in place so that they do not suffer in silence. Contrary to previous published studies, this study also attempted to procure a more homogenous sample. We recruited only families of children with ASD co-morbid with learning disability who attended a school for children with learning disability, where training and support would be routinely in place, in contrast to children with ASD in mainstream schools where the level and intensity of support varies greatly.

Methods

Participants

Target participants were Chinese families from Hong Kong who had a child with ASD co-morbid with learning disability and studying in a school for children with learning disability. Ethical approval was granted by the Joint Chinese University of Hong Kong–New Territories East Cluster Clinical Research Ethics Committee. Inclusion criteria included: (1) having a child with ASD co-morbid with learning disability; (2) sibling(s) aged between 6 and 18 years, attending a mainstream school and with no past or current psychiatric contact; and (3) parents able to understand Chinese. For each of the families recruited, 1 parent and 1 sibling of the child with ASD were included for the current study. If there was more than 1 sibling, the sibling whose age was closest to the child with ASD was chosen. The participants were recruited by convenient sampling on a voluntary basis through the child and adolescent psychiatric clinic of a university teaching hospital in Hong Kong and special schools for children with learning disability in the same catchment area as the clinic.

Procedures

Of the clinic participants, those with a diagnosis of ASD and co-morbid learning disability were identified when they attended follow-up at the children and adolescent psychiatry clinic and consent from their parents was sought for participation in the study. For the school participants, letters were first sent to schools for children with learning disability within the same catchment area as the clinic to explain the purpose of the study and inclusion criteria. The first author then held information sessions in the schools and invited parents to attend. Parents who agreed to take part signed the consent form and a convenient time was arranged for them to complete the questionnaires with the first author’s presence and assistance. Parents were also asked to bring the sibling who would be the subject of the study to the session to complete the sibling questionnaire.

Measures

Strengths and Difficulties Questionnaire

The Strengths and Difficulties Questionnaire (SDQ)²⁰ is a behavioural screening questionnaire for children aged 4 to 16 years. The current study used the parent’s version of the questionnaire. It consists of 4 problem subscales (emotional symptoms, conduct problems, hyperactivity / inattention, peer relationship problems) which when summed together to give the total difficulties score. A fifth subscale (prosocial behaviour) reflects the strength of the child in terms of prosocial behaviours. The scale has been translated into Chinese and validated in Hong Kong, with adequate reliability and validity.²¹ Cronbach’s alpha was reported to be 0.81 and test-retest reliability 0.86 for total difficulties score. Children whose total difficulties score was above 17 (which represents 85th percentile) were considered at high risk for psychopathologies.

General Health Questionnaire

The original version of the General Health Questionnaire (GHQ) was developed by Goldberg²² and is regarded as one of the most commonly used and reliable indicators of psychological stress. The 12-item version (GHQ-12) was used in this study and parents responded on a 4-point scale on how often they experienced the symptoms in the past 2 weeks, with a higher total score representing higher psychological stress. The Chinese version of the GHQ-12 was translated by Lai and Yue²³ and found it to be psychometrically sound (alpha = 0.85). The GHQ cut-off score was set at ≥ 3 by Tse et al.²⁴

World Health Organization Quality of Life Assessment (Brief Version)

The World Health Organization Quality of Life assessment (brief version) is a 26-item self-report questionnaire that assesses generic quality of life across 4 domains: physical health, psychological health, social relationships, and environment. The Hong Kong version was translated into Chinese by Leung et al,²⁵ with 2 indigenous questions added to the psychological health domain — ‘the availability of food’ and ‘acceptance by others’ — as these were considered to be culturally important. Parents assessed their satisfaction of life for the 4 domains over the past 2 weeks on a 5-point Likert scale, with higher scores representing a better quality of life. The Chinese translated version has been found to have sound psychometric properties, with satisfactory Cronbach’s alphas for the physical health (0.79), psychological health (0.76), social relationships (0.67), and environment (0.77) subscales. Satisfactory test-retest reliabilities, ranging from 0.64 to 0.90, are also reported.²⁵

General Functioning Scale of the Family Assessment Device

Parents completed the 12-item General Functioning Scale (GFS) of the Family Assessment Device (FAD). The FAD is a 60-item self-report questionnaire that measures family functioning along 7 dimensions: problem solving, communication, roles, affective responsiveness, affective involvement, behavioural control, and a GFS.^26,27 The GFS has sound psychometric properties and can be used as an independent scale. Mean scores of ≥ 2 on the GFS are indicative of family dysfunction. A Chinese translation of the GFS is available and has a Cronbach’s alpha of 0.92.²⁸

Sibling Stress Scale

Siblings were asked to complete the Sibling Stress Scale (SSS), a 33-item self-report questionnaire developed by Chan²⁹ to assess perception of sibling relationships. Siblings indicated whether they agreed or disagreed to the statements. The scale is scored by summing the total number of responses that indicate stress, with a maximum total score of 33. A higher score indicates higher stress. The Cronbach’s alpha was 0.78. Permission to use the questionnaire was granted by the original author.

Statistical Analysis

Data analysis was carried out using the Statistical Package for the Social Sciences Windows version 20.0 (SPSS Inc., Chicago [IL], US) when comparing scores between groups. Student’s t test and Chi-square test were used for dimensional variables and categorical variables, respectively. Pearson’s correlation was used to determine the correlations between SDQ scores and demographic and parents’ questionnaire scores. Analysis of variance was used to determine if there were score differences according to different demographic considerations. Linear regression was used to determine the contribution of different variables towards sibling adjustment as reflected by the SDQ score.

Results

Demographics

Altogether 116 siblings were recruited, 45 of whom were boys and 71 were girls. Their mean (± standard deviation) age was 12.3 ± 3.6 years and 82 (71%) were older than the child with ASD. Of the children with ASD, 102 (88%) were boys. Their mean age was 10.4 ± 4.1 years. Mean age spacing between the children with ASD and their siblings was 3.6 ± 2.2 years. The number of siblings (including the child with ASD) ranged from 2 to 5.

All except 10 of the families were two-parent families. The mean age of the fathers was 46.4 ± 5.6 (range, 35-61) years and 43.6 ± 5.2 (34-57) years for the mothers. The majority of parents had received secondary (57% of fathers, 63% of mothers) or tertiary education (35% of fathers, 28% of mothers).

Sibling Adjustment

Mean (± standard deviation) total difficulties score of the siblings was 13.5 ± 5.4. Boys had a mean score of 13.7 ± 5.6 that was not statistically different to the community’s normative score of 12.3. Girls had a mean score of 13.2 ± 5.6, significantly higher than the community norm of 11.2 (p < 0.01, Cohen’s d = 0.38). Adopting a score of 17 as the cut-off,²⁰ over a quarter of the siblings (n = 33, 28%) were rated as being at high risk of adjustment problems. Analysis by gender found slightly more boys than girls scored above the cut-off (31.7% vs. 28.4%) but the difference was not statistically significant. Using Pearson’s correlations, no significant correlation was found between the age of siblings and total difficulties score. Using the age of 12 to arbitrarily distinguish between childhood and adolescence, the proportion of siblings who scored above the cut-off was similar in both age-groups (27% vs. 30%). Further data are shown in Table 1.

When comparing sibling subscale scores against community norms, both boys and girls had a significantly elevated peer relationship problem score (p < 0.001, Cohen’s d = 1.02 in both genders), and lower (poorer) prosocial behaviour score (boys: p < 0.01, Cohen’s d = 0.59; girls: p < 0.001, Cohen’s d = 0.86). Girls also had a slightly elevated hyperactivity score (p < 0.05, Cohen’s d = 0.28).

Sibling Stress

The mean total SSS score was 13.5 ± 5.6 (range, 5-26). The proportion of “agree” and “disagree” responses for many of the statements was largely evenly distributed, indicating that about 50% of sibling endorsements indicated stresses in their sibling relationship. Several items stood out because a much higher percentage of sibling endorsements indicated stress, e.g. the statement that parents “expect me to be considerate to his / her (child with ASD) needs” was agreed by two-thirds of the siblings; and only a third agreed to the statements that “He / she is always my playmate” and “When he / she throws a temper tantrum, I know how to handle it”. Only a quarter agreed to the statement “I am proud of him / her”. Yet, siblings were also concerned for the welfare of their autistic sibling; two-thirds confirmed that they were worried about their siblings’ future and that other people would tease or play tricks on him / her.

Parental Psychological Stress and Family Functioning

Mean GHQ score for parents was 2.1 ± 3.0 (range, 0-12). Based on a cut-off score of 3, nearly a third (n = 35, 30%) of the parent respondents were considered at risk of psychological distress.

The mean score of GFS of the FAD was 2.14 ± 0.42, and 78% (n = 91) of the parent ratings had a mean score of ≥ 2, which indicated problematic family functioning.

Subjective quality of life (QoL) of parents was also poor. Scores of all 4 domains were significantly lower when compared with the local normative data, including physical health (t[114] = –10.573, p < 0.001), psychological health (t[114] = –8.052, p < 0.001), social relationships (t[114] =–5.295, p < 0.001), and environment (t[114] = –8.149, p < 0.001). This indicates that parent perception of these 4 areas were significantly less favourable than those of the Hong Kong population.

Factors Predicting Sibling Adjustment

Demographic Risk Factors

To examine whether sibling gender or birth order were demographic risk factors, a 2 x 2 (sibling gender x sibling birth order) analysis of variance was carried out and SDQ total difficulties score was used as the dependent variable. Results showed no significant main or interaction effect. Further analysis using SDQ problem subscales and prosocial scores as dependent variables, and 2 x 2 (sibling gender x sibling birth order) multivariate analysis of variance again found no main or interaction effect.

Psychosocial Risk Factors

The relationship between sibling adjustment (SDQ total difficulties score) and family stressors (parental distress, QoL, family functioning and sibling stress) was first examined using Pearson correlations. Results found significant correlation of SDQ total difficulties score with parent score on QoL physical health (r = –0.22, p < 0.05), social relationships (r = –0.25, p < 0.01) and environment (r = –0.30, p < 0.01) domains, as well as GFS score (r = 0.20, p < 0.05). The GHQ score (for parents) and SSS score (for siblings) were not associated with SDQ total difficulties score. Entering these significantly correlated factors as predictors and SDQ score as a dependent variable into multiple linear regression analysis revealed a significant prediction that accounted for approximately 10% of the variance of the SDQ total difficulties score (F[4,112] = 3.30, p < 0.05; R² = 0.105). Nonetheless, none of the predictors independently predicted the total difficulties score. Further data are shown in Table 2.

Of the SDQ subscale scores, because the peer relationship problem score was significantly elevated compared with the community norm, further analysis was made by examining correlations between that subscale and the above predictors. No association was found with any of the predictors. In terms of prosocial score, the only significant correlation was with parent QoL environment score (r = 0.45, p < 0.001), such that a higher satisfaction in QoL environment score was associated with a higher (better) prosocial score.

Discussion

This study explored the adjustment of 116 siblings of Chinese children with ASD and factors that influence their adjustment. Ratings from parent SDQ total difficulties score were mildly elevated when compared with community norms, and this was slightly more marked for girls. Nonetheless, parents did not find the siblings to have more emotional or behavioural problems, but were concerned about their peer relationships and perceived them to be engaged in fewer prosocial behaviours than community children. This pattern of results is similar to those reported in western studies which also reported increased concern about siblings’ peer relationships and prosocial behaviours.^3,7 In line with the concept of the BAP,¹⁵ such concerns could reflect subtle autism spectrum difficulties in the siblings due to their genetic predisposition. On the contrary, it is also possible that sibling’s apparent difficulties with peer relationships are due to issues such as feeling stigmatised due to having a sibling with ASD, or parental increased sensitivity or expectations about their typically developing social competencies.⁴

Despite having similar mean scores to community children, when a cut-off score was used to screen for those who are potentially at risk of mental health problems, over a quarter were considered at risk. This is a much higher percentage than the community prevalence rates of mental health problems among adolescents in Hong Kong, previously estimated to be 16.4%.³⁰ This observation has also been reported in western studies, where a significantly higher percentage of siblings had clinically significant scores although the whole sample mean scores were within the average range.^7,31 Ours was a screening prevalence that would be expected to be higher than a diagnostic prevalence. Nonetheless, when considered along with parental concern about siblings’ poor peer relationships and weak prosocial behaviours, it becomes evident that attention to sibling adjustment is warranted.

Similar to most of the published findings, this study found that siblings’ adjustment was not predicted by age, gender, or sibling order. Nonetheless, family stresses, as reflected by parental subjective QoL and family functioning, emerged as significant predictors. In our study sample, family functioning was rated by many to be problematic, and parents’ QoL across physical health, psychological health, social relationships, and environment domains were worse than those of community populations. While it again highlights the stresses families experience in looking after children with ASD, it is not surprising that such stresses impact on the adjustment of the siblings, and has been a consistent finding among studies.^6,10,12,13

Another finding from this study was that many siblings endorsed experiences that could be indicative of a stressful sibling relationship. Although this did not emerge as a predictor of their adjustment, it is important that parents and professionals managing children with ASD are attuned to the voices of the siblings, and be aware that they may feel burdened by their everyday encounters with the ASD sibling. This may be an area that is particularly difficult for siblings and families to acknowledge and discuss, given the cultural expectation that an individual’s needs are subordinated below that of family needs, and that siblings, especially if they are not disabled, should help care for and tolerate a disabled sibling’s condition, thus for typically developing siblings to express such stress or ambivalence could be perceived as non-filial and therefore disapproved of. Clinicians have an important role to play in being the advocate and facilitating a discussion.

The current study represents one of very few to explore the psychological adjustment of siblings of autistic probands in Hong Kong. One of the strengths of the study is its relatively large sample size compared with previous local studies¹⁹ and the use of an assessment instrument that, besides emotional and behavioural concerns, taps into peer relationship and prosocial behaviours. Nonetheless, no conclusion can be drawn about the objective nature of the parents’ concern about sibling peer relationships and their prosocial behaviours at this juncture as this study did not screen for the presence of autistic symptoms among the healthy siblings, and parents were the only source of information. Moreover, a qualitative approach by interviewing the siblings would also shed more light on their experience and concerns.

Other limitations of the study also need to be noted. First, the profile of the probands’ behaviour was not systematically assessed. Although all probands had co-morbid learning disability and were attending schools with stipulated support in place, the pattern of the proband behaviours could have been very different and it is conceivable that the impact thus brought upon family members would affect their adjustment. Second, the absence of a control group meant that it was not possible to compare the adjustment of siblings of children with other developmental or chronic conditions. It is unclear whether parent concerns are specific to siblings of a child with ASD. Future studies should address these shortcomings to gain further insight.

From this study, we can tentatively conclude that although there appeared to be no marked overall negative impact on the emotional and behavioural adjustment of typically developing siblings of children with ASD, parents were concerned about their peer relationships and prosocial behaviours. It will be important in future studies to examine this in more detail. While it may be due to siblings having subtle autistic difficulties, there may also be other aspects of living with a sibling with ASD that affect their social behaviour, such as the feeling of stigmatisation. At the same time, parental QoL and family functioning were significant predictors of sibling adjustment. This should alert professionals who manage children with ASD that it is paramount to assess and address the psychosocial needs of the whole family, and adopt a holistic approach when helping these families. Sibling adjustment should also be part of the discussion and any concerns should be addressed.

Declaration

The authors have disclosed no conflicts of interest.

References

1. Diagnostic and Statistical Manual of Mental Disorders, 5th edition (DSM-5). Washington, DC: American Psychiatric Association; 2013.
2. Centers for Disease Control and Prevention, 2012. Available from: http://www.cdc.gov/ncbddd/autism/data.html. Accessed 2016.
3. Meadan H, Stoner JB, Angell ME. Review of literature related to the social, emotional, and behavioural adjustment of siblings of individuals with autism spectrum disorder. J Dev Phys Disabil 2010;22:83-100.
4. Dempsey AG, Llorens A, Brewton C, Mulchandani S, Goin-Kochel RP. Emotional and behavioural adjustment in typically developing siblings of children with autism spectrum disorders. J Autism Dev Disord 2012;42:1393-402.
5. Hesse TL, Danko CM, Budd KS. Siblings of children with autism: predictors of adjustment. Res Autism Spectr Disord 2013;7:1323-31.
6. Hastings RP, Petalas MA. Self-reported behaviour problems and sibling relationship quality by siblings of children with autism spectrum disorder. Child Care Health Dev 2014;40:833-9.
7. Griffith GM, Hastings RP, Petalas MA. Brief report: Fathers’ and mothers’ ratings of behavioural and emotional problems in siblings of children with autism spectrum disorder. J Autism Dev Disord 2014;44:1230-5.
8. Tomeny TS, Barry TD, Bader SH. Are typically-developing siblings of children with an autism spectrum disorder at risk for behavioural, emotional, and social maladjustment? Res Autism Spectr Disord 2012;6:508-18.
9. Petalas MA, Hastings RP, Nash S, Lloyd T, Dowey A. Emotional and behavioural adjustment in siblings of children with intellectual disability with and without autism. Autism 2009;13:471-83.
10. Orsmond GI, Seltzer MM. Adolescent siblings of individuals with an autism spectrum disorder: testing a diathesis-stress model of sibling well-being. J Autism Dev Disord 2009;39:1053-65.
11. Tomeny TS, Barry TD, Bader SH. Birth order rank as a moderator of the relation between behaviour problems among children with an autism spectrum disorder and their siblings. Autism 2014;18:199- 202.
12. Meyers KA, Ingersoll B, Hambrick DZ. Factors influencing adjustment in siblings of children with autism spectrum disorders. Res Autism Spectr Disord 2011;5:1413-20.
13. Petalas MA, Hastings RP, Nash S, Hall LM, Joannidi H, Dowey A. Psychological adjustment and sibling relationships in siblings of children with autism spectrum disorders: environmental stressors and the broad autism phenotype. Res Autism Spectr Disord 2012;6:546-55.
14. Benson PR, Karlof KL. Child, parent, and family predictors of latter adjustment in siblings of children with autism. Res Autism Spectr Disord 2008;2:583-600.
15. Bauminger N, Yirmiya N. The functioning and well-being of siblings of children with autism: behavioural-genetic and familial contributions. In: Burack JA, Charman T, Yirmiya N, Zelazo PR, editors. The development of autism: perspectives from theory and research. London: Lawrence Erlbaum Associates Publishers; 2001: 62-80.
16. Walton KM, Ingersoll BR. Psychological adjustment and sibling relationships in siblings of children with autism spectrum disorder: risk and protective factors. J Autism Dev Disord 2015;45:2764-78.
17. Gau SS, Chou MC, Lee JC, Wong CC, Chou WJ, Chen MF, et al. Behavioural problems and parenting style among Taiwanese children with autism and their siblings. Psychiat Clin Neurosciences 2010;64:70-8.
18. Chan WL, Goh EC. My parents told us that they will always treat my brother differently because he is autistic’ — Are siblings of autistic children the forgotten ones? J Soc Work Pract 2014;28:155-71.
19. Sheh CS. The psychological adjustment of the siblings of autistic children [thesis]. Hong Kong: The University of Hong Kong; 1996.
20. Goodman R. The Strengths and Difficulties Questionnaire: a research note. J Child Psychol Psychiatry 1997;38:581-6.
21. Lai KY, Luk ES, Leung PW, Wong AS, Law L, Ho K. Validation of the Chinese version of the strengths and difficulties questionnaire in Hong Kong. Soc Psychiatry Psychiatr Epidemiol 2010;45:1179-86.
22. Goldberg DP. The detection of psychiatric illness by questionnaire: A technique for the identification and assessment of non-psychotic illness. London: Oxford University Press; 1972.
23. Lai JC, Yue XD. Measuring optimism in Hong Kong and mainland Chinese with the revised Life Orientation Test. Pers Individ Dif 2000;28:781-96.
24. Tse AW, Lai LH, Lee CC, Tsoi KK, Wong VW, Chan Y, et al. Validation of self-administered questionnaire for psychiatric disorders in patients with functional dyspepsia. J Neurogastroenterol Motil 2010;16:52-60.
25. Leung KF, Tay M, Cheng SS, Lin F. Hong Kong Chinese version: World Health Organization Quality of Life Measure–abbreviated version Report of the Hong Kong Project Team on the Development of the Hong Kong Chinese version, WHOQOL. Hong Kong: Hospital Authority; 1997.
26. Epstein N, Baldwin L, Bishop D. The McMaster Family Assessment Device. J Marit Fam Ther 1983;9:171-80.
27. Kabacoff RI, Miller IW, Bishop DS, Epstein NB, Keitner GI. A psychometric study of the McMaster Family Assessment Device in psychiatric, medical and non-clinical samples. J Fam Psychol 1990;3:431-9.
28. Shek DT. The General Functioning Scale of the Family Assessment Device: does it work with Chinese adolescents? J Clin Psychol 2001;57:1503-16.
29. Chan YE. An exploratory study of the stress and adjustment in siblings of exceptional children [thesis]. Hong Kong: The University of Hong Kong; 1994.
30. Leung PW, Hung SF, Ho TP, Lee CC, Liu WS, Tang CP, et al. Prevalence of DSM-IV disorders in Chinese adolescents and the effects of an impairment criterion: a pilot community study in Hong Kong. Eur Child Adolesc Psychiatry 2008;17:452-61.
31. Ross P, Cuskelly M. Adjustment, sibling problems, and coping strategies of brother and sisters of children with autistic spectrum disorder. J Intellectual Dev Disabil 2006;31:77-86.