Introduction
Anxiety is among the most prevalent disorders [1]. In children and adolescents, its prevalence is 4.7%-9.1% worldwide [2]. The most anxiety types include Generalized Anxiety Disorder (GAD) and Social Anxiety Disorder (SAD). Emotions significantly affect anxiety [6]; thus, anxiety and depression are comorbid conditions in children and adolescents [7]. Depression and anxiety in children might be related to their laterality status. However, the difference between sinistral and dextral depressed children in terms of GAD and SAD remains unclear. Studies have suggested that hemispheric lateralization defects (limb preference as an indicator for hemisphere dominance) are associated with the development of mental disorders [12 ،11]. Various studies also investigated the relationship between depression and lateralization in healthy populations. For example, sinistral individuals are significantly more prone to depressive symptoms than dextral individuals. However, it is difficult to identify a clear pattern in the relationship between handedness and depression [16]; in particular, the role of lateralization and depression concerning other disorders, like children's anxiety, remain undiscovered. However, Logue et al. [18] have documented that left-handedness is a phenotypic risk factor for mental disorders, such as depression and anxiety, and increases the severity of such disorders.
There is evidence regarding the relationship between depression and anxiety and laterality. Prior research also explored the depression and anxiety levels among left- and right-handed individuals. Therefore, this study aimed to compare GAD and SAD in the nonclinical samples of depressed children with different lateral dominance (sinistral and dextral).
Participants and methods
This was a cross-sectional study with a causal-comparative design. The study population consisted of all primary students (fourth to sixth grade) of Arak Province, Iran, in the 2017-2018 academic year. The study samples were determined by a convenience sampling method. Prior to the study, they completed the following questionnaires: Children's Depression Inventory of Kovacs and Beck [23], Generalized Anxiety Disorder Scale developed by Spitzer et al. [27], and Liebowitz Social Anxiety Scale for Children and Adolescents developed by Masia-Warner et al. [29]. Then, those with depression scores of ≥19 were purposively selected and assigned into two groups of sinistral (n=31) and dextral (n=35). Their obtained data were compared using Multivariate Analysis of Variance (MANOVA).
Results
The MANOVA results indicated a significant difference in GAD and SAD between the study groups [Wilks’ lambda= 0.594; F63,2= 21.547; Eta squared =0.406; P=0.001]. Univariate ANOVA test was used to investigate the between-group differences in terms of the dependent variables. The achieved results reported that depressed sinistral children had higher GAD scores, compared to depressed dextral children; however, they were not significantly different in terms of SAD scores.

Conclusion
The study results revealed that depressed sinistral children had higher GAD scores, compared to depressed dextral children; however, they were not significantly different in terms of SAD scores. Various studies have suggested that left-handed individuals generally exhibit more mental disorders (especially depression and anxiety), compared to right-handed individuals [11-17]; however, we found no study that accurately addressed the difference between depressed sinistral and dextral children in terms of GAD and SAD. 
The collected results revealed that depressed sinistral children exhibit more GAD scores. This finding is consistent with those of Logue et al. [18] and Bruder et al. [20]. Our study also reported no difference between the depressed sinistral and dextral children in terms of SAD; these data are consistent with those of Bruder et al. [20]. Furthermore, depression and anxiety are typically highly comorbid; the two groups of children with depression are expected to experience high anxiety levels; however, what justified the difference in anxiety levels between the two depressed groups was probably related to their lateral dominance. In other words, the depressive psychological context in sinistral children, compared to dextral children, makes them more susceptible to anxiety disorders, especially GAD. Therefore, left-handedness increases anxiety risk in depressed children.
Based on the results, in addition to preventing and treating depression, children require further preventive and treating measures for anxiety disorders, especially GAD; this helps to improve their health by reducing depression and anxiety. Therefore, it is recommended that mental health practitioners anticipate and implement specific programs and training for children with depression, especially sinistral ones.
Ethical Considerations
Compliance with ethical guidelines
The authors observed the standards of writing based on the recommendations of the International Committee of Medical Journal Publishers.
This study obtained its ethical approval from the Research Ethics Committee of Arak University of Medical Sciences (code: IR.ARAKMU.REC.1397.298).


Funding
This study was part of a research proposal approved by the Deputy of Research and Technology of Arak University (code:97/15017).
Authors' contributions
Conceptualization, methodology, formal analysis: Tooraj Sepahvand; Investigation, resources, data curation, writing -original draft preparation, writing-review & editin: Tooraj sepahvand, Jalil Moradi.
Conflicts of interest
The authors declared no conflicts of interest.
Acknowledgements
 The authors would like to thank the Deputy of Research and Technology of Arak University.

References