In the present study, the age of the studied children ranged from 6 to 12 years. The selection of this age group is important because this period of life is crucial for healthy physical, emotional, and social development and acquisition of effective coping skills .
The results of the present study showed that 19.0% and 18.7% of the studied sample of children as reported by parents and teachers, respectively, had probable CPD, according to SDQ. Similar findings were revealed in US children surveillance, where a total of 13–20% of the studied children experienced a mental disorder . Moreover, other studies had shown that between 13% and 18% of preschool children suffer from some sort of psychopathology .
However, in an Egyptian study of emotional and behavioral disorders among children aged 6 to 12 years old in Minia using SDQ, the prevalence was higher than that of our present study (34.7% and 20.6% as reported by teachers and parents, respectively) . A high prevalence of CPD (34.5%) was found also in Pakistan and Bangladesh [26, 27]. It is possible that this pattern of high prevalence of problem symptoms is a specific feature of developing countries during the period of transition .
Our results revealed there was no statistically significant difference between parents and teachers regarding the diagnostic result of SDQ. Alternatively, other studies revealed higher frequency of CPD using SDQ reported by teachers than that reported by parents (11.1% vs 8.7% in UK and 34.7% vs 20.6% in Egypt) [4, 28]. This result may be due to the fact that high rates of externalizing problem behaviors are usually reported by teachers among their students and this might account for the greater problem rates . On the other hand, some parental expectations are of stricter self-control among younger children, leading to higher rates of perceived (but perhaps non-pathological) problems . So, many researchers stressed on the importance of collecting information from the two informants (parents and teachers) .
In the present study, CPD was statistically associated with older age group (children aged 9–12 years old). This result agrees with that of other studies, where mental disorders in childhood were found to increase with age .
Research results show that a higher percentage of males (25.3%) was diagnosed by SDQ to have CPD compared to a lower percentage of females (14.9%). This result agrees with that of another Egyptian study that was conducted in Minia where 22.0% of the studied males were diagnosed to have CPD compared to a lower percentage of females (19.2%) .
Moreover, our result agrees with that of another study, where a person’s socioeconomic class was found to outline the psychosocial, environmental, behavioral, and biomedical risk factors that are associated with mental health . Also, in another study, mental illness and poverty were considered to interact in a negative cycle .
Also, there were statistical significant relations between CPD of the studied children and their body mass index (BMI), maternal history of problems with pregnancy, history of receiving medications during pregnancy, abnormal general condition of baby at birth, and family history of mental disorders (P < 0.05). A significantly higher percentage of children’s mothers with CPD (66.7%) had experienced problems during pregnancy compared to (13.4%) with no history of problems during pregnancy. Similarly, another study suggested increased rates of schizophrenia in offspring for women suffered from problems during pregnancy .
Moreover, many of the putative prenatal risks such as maternal smoking, stress, and diseases in pregnancy are ones that tend to be associated with postnatal risks including offspring psychiatric disorders. However, as mothers transmit genes to their offspring, there is a possibility that the associations arise through mothers and offspring sharing some of their genome rather than because of a true prenatal risk effect . Swanson & Wadhwa  reported that exposure to early adversity during a sensitive period of development is thought to lead to structural, physiological, and metabolic changes in the fetus that do not cause recognizable defects but increase susceptibility to later disease. Also, malnutrition, low birth weight, and certain micronutrient deficiencies (such as iodine deficiency) significantly increased the risk to brain development, as do risky health behaviors in pregnancy, especially the use of tobacco and drugs [33, 34].
Moreover, another study found a significant relation between BMI and CPD among young children which become a risk factor to eating disorder . An increased risk of psychosocial distress such as negative self-perception, social, or behavior problems was found among a subset of obese children and adolescents .
In the present study, there were significant relations between CPD of the studied children and history of congenital diseases, acute medical disorders, chronic diseases, and receiving medications. Similarly, several surveys have found that chronically ill children are at greater risk for developing behavioral or emotional problems than healthy children, although such effects have not been found for all categories of chronic diseases . The increasing understanding of brain plasticity (neuroplasticity) raises questions of whether infections or toxins trigger a change in the brain chemistry, which can develop into a mental disorder .
In the current study, there was high statistically significant relation between CPD among the studied sample of children and past history of trauma (psychic or physical). Similarly, several studies proved that exposure to trauma (psychic or physical) that is associated with marked effect on body or feelings was associated with increased risk of CPD in the children .
Added results, there was high statistically significant relation between CPD among the studied children and family problems, living with single parent, parent(s) death, major changes in the family, and parent(s) addiction. Loss of one or both parents can have negative effect on the psychosocial status of children. The individual may feel fear, guilt, anger, or loneliness. This can drive a person into solitude and depression .
Other risk factors for CPD include living with a parent who is a drug abuser, stress, homelessness, poor housing, and social disadvantage [36, 38].
Our finding revealed that statistical significant relations between CPD among the studied children and their academic achievement, the interrelation between academic achievement and CPD has been proved by many researches as there is clear evidence that children who are emotionally or mentally healthy achieve more at school . Also, children with mental problems can also adversely affect the social and academic environment for others in their school  However, a continuing debate on the relative impact of the home/work/school environment and peer groups on children mental health is still an important issue that needs further research activity . The results of the present study revealed statistically significant relations between CPD among the studied children and problems with teachers, problems with peers, and exposure to violence. Similarly, other studies suggested several risk factors for childhood psychosocial problems including, childhood abuse, trauma, violence or neglect, social isolation, and loneliness or discrimination .
In the current study, there was no statistically significant relation between CPD among the studied children and living nearby a source of pollution and long use of television and computer (P > 0.05). However, a Swedish study found a link between exposure to air pollution and dispensed medications for certain psychiatric disorders in children and adolescents even at the relatively low levels of air pollution . Furthermore, children in Spain who attended schools with higher traffic-related air pollution have been observed to have a smaller improvement in cognitive development than children who attended schools with lower traffic-related air pollution . This discrepancy may be explained by lack of awareness of sources of pollution among surveyed parents.
Strengths and limitations of the study
One of the most important strengths of this study was assessing CPD among the studied sample of children using SDQ which is a standardized validated questionnaire which allows comparison of results among different countries and cultures. Also, in the present study, data was collected from the two informants (parents and teachers). However, one of the weaknesses of the study is that no independent confirmation of the diagnosis was made in children identified with probable disorders. Reliability and validity of the designed questionnaires were not tested. Also, Reliability of the teachers as a source of information in public schools due to large number of students in classes that may be one explanation of lower psychosocial comorbidities relative to other studies.