1.  Introduction

Attention Deficit Hyperactivity Disorder (ADHD) is the most common childhood-onset neurobiological disorder that affects school learning and socialization. The Diagnostic Statistical Manual of Mental Disorders (DSM-V) describes ADHD as typified by pervasive and impairing symptoms of inattention, impulsivity and hyperactivity [1]. It is estimated to affect between 9.5 and 16% of all school age children [2-4]. ADHD has a negative impact on multiple domains of Quality of Life (QOL) for children, adolescents and their families including social, academic and family life. Thus, early detection and management is essential to improve overall outcome.

Attention-Deficit Hyperactivity Disorder (ADHD) is characterized by age-inappropriate impulsivity, impaired attention, hyperactivity or a combination [5]. These behaviors have a broad range of negative outcomes for patients and their families. The symptoms of ADHD have been shown to negatively impact children’s self-esteem and social function which includes their behavior, academic success and quality of life and their families [5,6]. Negative outcomes of untreated ADHD.

ADHD has been associated with a broad range of negative outcomes for children such as academic underachievement including lower grades, attendance, graduation rate and even dismissal from school. Families of children with ADHD experience increased stress. A person with ADHD could be affected as an adult when it comes to success at work and relationship forming [7-9]. Furthermore, a study of the Cost of Illness (COI) estimated annual COI of ADHD in children and adolescents at between $12,005 and $17,458 per individual which included health care costs, education (special education), and juvenile justice [10]. A European study found similar cost of illness results [11].

1.1.   Academic Failed/Lower Grades

Loe and Feldman’s (2007) [12] review of the literature found in longitudinal studies that academic underachievement associated with ADHD was persistent and began early in life. Children with ADHD repeated the academic year, achieved lower ratings in all subjects on report cards and performed comparatively poor in standardized tests than the control group. A further review of the literature by Daley and Birchwood (2010) [13] looked at the relationship between ADHD and academic performance at different developmental stages; they found that students taking stimulant medication did better academically than those with ADHD not receiving medication. Meta-analysis has demonstrated that the use of Methylphenidate (MPH) medication with children with ADHD improved math and reading abilities of these students but had a much greater improvement on their behavior [5]. Methylphenidate has been shown to improve academic performance in Primary school children and interestingly found more improvement the later the child started medication. Furthermore, it was found that these children were still below that of typical peer performance [14].

1.2.   Attendance/Graduation

School histories illustrated persistent problems in socialization with students with ADHD taking more years to complete high school and having lower rates of college attendance and graduation. [12]. A European meta-analysis showed that children with symptoms of ADHD had increased dropout rates compared to their counterparts not experiencing these symptoms and therefore this added to lower graduation rates [15].

1.3.  Lack of Success as Adult

Untreated ADHD is a principal cause of lack of success for many adults. Research has established that teenagers and young adults with untreated ADHD have less probability of attending college or university, they get in trouble with the law more frequently, are more frequently found in prisons, experience more divorce or difficulty with relationship forming and durability and do not achieve their potential at workplace. The social and emotional impairments associated with ADHD affect the quality of life for these adults and their families. If left untreated, these people could become a burden on their family and society [11,12,16-21].

1.4.  Family Wellbeing

Family wellbeing i.e. relationships within families and between siblings was often reported lower for those with untreated ADHD compared to those who do not have ADHD [22]. In a large cross-sectional study of QOL for children with ADHD, parents’ response demonstrated that QOL of children with ADHD was positively linked with treatment [6]. In a review of the literature, researchers concluded that ADHD seriously compromises quality of life, especially when seen from parents’ perspective. Reports of the family’s QOL and well-being were more compromised where increased symptoms of ADHD were experienced by the child. They also found evidence that QOL of the child improved with the use of stimulant medication [23].

1.5.  Home Disruption -Siblings

Kendall (1999) [24] in her qualitative study of parent and sibling accounts in families with at least one child diagnosed with ADHD asked siblings to write in diaries once a week for eight weeks and in-depth interviews were conducted with the siblings and parents. Results of these interviews found that disruption to home life was the most common and significant problem. Children described their family life as chaotic, full of conflict and exhausting. Some children stated that living with a sibling with ADHD meant never knowing what to expect next and hopelessness that it would never change. More recent studies of sibling perceptions also found the siblings without ADHD believed themselves to be negatively impacted by having a brother or sister at home with ADHD that received different treatment, discipline and more attention. This need for extra time and assistance often lead to feelings of being ignored. Findings signified that a child with ADHD does have a huge impact on the family. Parent Stress

Anastopoulos, et al.’s (1992) [16] study of parent stress and ADHD found that parents of children with ADHD scored extremely high, above the 90th percentile, on a well-known parenting stress index. Parental stress or quality of life was also reported to be poorer for those with untreated ADHD compared to those who do not have ADHD. Mothers found inattention and opposition most stressful but not hyperactivity, whereas, fathers were more distressed by opposition and aggression [20]. Muñoz-Silva, et al (2017) [25] also found that the association between ADHD and parent stress was attributable to children’s conduct problems and the negative impact on the family’s social life. Overall, parent and family stress impacts quality of life when there is a child with ADHD in the family [22].

1.6.  Financial Burden

Burd, et al (2003) [26] found that annual mean direct treatment costs for children aged between 0-21 years old with ADHD was $870 compared to $663 for controls. Leibson, et al (2001) [27] longitudinal study found that median direct treatment costs of children aged between 5-19 years old with ADHD was $6,158 compared to $2,780 for controls. This study was conducted over 9 years. Mandell, et al (2003) [28] looked at children aged between 3-15 years old with ADHD and no psychiatric disorder over 3 years. The mean direct treatment cost was $4,891 for ADHD patients compared to $221 for patients with no psychiatric disorder.

We know that up to 70% of those diagnosed with ADHD in childhood continue to have symptoms in adulthood [29]. Secnik et al (2005) [30] and Swensen et al (2003, 2004) [31,32] compared costs of care for adults with ADHD with controls matched on age, sex, area or residence, insurance cover and found that those with ADHD have considerably higher annual medical costs than matched controls ($4,929 to 5,651 vs $1473 to $2,771). Identification No laboratory tests reliably predict ADHD [33]. Procedure for identifying a person with ADHD starts at home or at school. Usually parents or teachers identify that there is a behavioral or academic problem with the child. Sometimes a school psychologist assists in this diagnosis, but Qatari schools generally do not have the luxury of these services. Frequently, school administrators or specialized teachers become involved to assist a child with ADHD difficulties. Sometimes parents take their child to a pediatrician, psychiatrist, or private psychologist for assistance.

1.7.  Treatment

Treatment of ADHD usually involves a multi-modal approach which includes pharmacological and non-pharmacological options. Stimulants are the first drug of choice in the management of ADHD symptoms [14]. Methylphenidate (MPH) is the first line treatment and has been used for over 50 years [34]. It is the most commonly prescribed drug treatment for this disorder [35]. MPH medications are an effective way of managing symptoms of ADHD such as improving attention span, reducing distractibility, improving memory, reducing impulsivity and hyperactivity [36,37].

There is broad public concern about rates of stimulant prescription for ADHD treatment and stimulant usage remains a contentious issue. With the plethora of negative information and articles in the popular press and on the internet with respect to the number of children being prescribed medication for behavioral issues, parents are often hesitant to agree to medication for their child who is seen to have a behavioral problem that some believes to be caused by the school [38]. In her study, Arcia (2004) [39] found that mothers preferred treatment other than medication for their child with ADHD. In a study with parents of children taking stimulant medications for ADHD, 55% were reluctant to give their child medication based on information in the local press and 38% thought that too many children receive medication for ADHD [40]. Other researchers have found similar results when examining parents’ resistance to give their children medication for behavioral difficulties [41-43].

The medically accepted treatment of stimulant medication is highly effective but does not always provide complete amelioration of the symptoms of ADHD, especially the focus and attention required in many school settings [44]. In addition, there are those children for whom stimulant medication is not providing the desired result or who experience side effects from the medication and do not or cannot take medication. Thus, the child is left without the required support that they may need to become a successful productive student and member of society. Furthermore, without support, the child ends up less successful in school and is often alienated socially with law enforcement troubles in adolescence [41,45-47].

1.8.  Side Effects of Methylphenidate Use in Children

There is a wide range of side effects experienced by children and adolescents when taking stimulant medication ranging from lack of appetite to increased aggression and somatic symptoms such as headache and gastrointestinal complaints. Participants in Efron et al.’s (1997) [48] study reported side effects like prone to crying (71%), staring (62%), anxiety (61%), sadness (56%), nail biting (45%), euphoria (43%) and less talking (42%). In another study, Haertling et al. (2015) [49] reported only 13.7% of participants experienced side effects. Yet Khajehpiri et al. reported 100% of their participants experienced side effects. Thus, it is important to look at the side effects experienced in our study and to ensure that we are aware and can assist children and families who experience these as it may deter continuation of medication treatment for children. Why this research is needed: Qatar experience. The prevalence of ADHD in school age children in Qatar has been shown to be like worldwide prevalence [50]. However, there are no studies examining ADHD treatment outcomes in Qatar. There are a limited number of studies from neighboring countries in the region on ADHD. Most of these studies explore epidemiology [51-53]. A study that included Egypt, Lebanon, and the U.A.E. explored predictors for treatment outcomes of MPH but did not examine the academic outcomes [54].

An estimate of prevalence in Qatar suggests up to 19% of Qatari children aged 6-12 years in government schools have moderate to high levels of ADHD according to teacher rating scales [50,55]. This equates to more than 15000 Qatari students who may or may not be receiving treatment for a potentially debilitating disorder that can limit a person’s success in life. A study by Rhee and Waldman (2002) [56] established familial or biological links in people with ADHD. In their clinic-referred sample, 34-40% of the subjects with ADHD reported a family history of ADHD compared to 8% of control subjects. Considering these studies of familial links there is support for further research in Qatar where consanguineous marriage is common.

2.  Materials and Methods

2.1.  Study Statement

The primary focus of this study was to examine whether MPH improves the behavior, academic success and family wellbeing of those affected with ADHD in Qatar. We also explored the adverse effects profile as a secondary focus. We aimed to explore the effects of MPH use in a comprehensive setting including the home and the academic environment as reported by teachers and parents. We hypothesized that the use of MPH will improve attention, reduce hyperactivity and improve academic achievement and family wellbeing. We also hypothesized that the side effect profile for MPH will be like those in other countries - decreased sleep and appetite being the most common.

2.2.  Participants

Participants in this study included 101 patients who fulfilled the diagnostic criteria for ADHD according to the DSM-V and had inattention, behavioral problems, hyperactivity, impulsivity and/ or aggressive behavior along with inattention affected academic difficulties due to ADHD. Participants were enrolled at Hamad Medical Corporation outpatient clinic. Seventy-five percent of participants were males and 25% females. Participants’ age ranged from 5 - 18 years old and they were all enrolled in Qatar’s Government schools. The demographics of the patient population are outlined in (Table 1). Along with ADHD, participants were also diagnosed with co-morbidities, the main ones being learning disability 17 (16.6%), autism spectrum disorder 4 (3.9%), anxiety 4 (3.9%) and depression 2 (2%). The presenting symptoms of the patient population are mentioned in (Figure 1). DSM-V The DSM-V ADHD checklist includes a list of nine symptoms of inattention and nine symptoms of hyperactivity/impulsivity [57]. It is the standard measure for ADHD diagnosis. Based on the DSM-V criteria, a child must display six out of the nine symptoms in at least one of the two areas or both areas (inattention, hyperactivity-impulsivity, inattention and hyperactivity-impulsivity) to be diagnosed with ADHD. SNAP IV Swanson, Nolan and Pelham SNAP-IV Questionnaire is an 18-item questionnaire measuring the full DSM-V criteria of ADHD (9 items questioning inattention and 9 items questioning hyperactivity) that has high reliability and validity [58]. It uses a four-point scale of frequency for each item (3 = very much, 0 = not at all). A pilot of all the survey questions was conducted prior to the study to ensure the questions are readable and comprehensible, and that the Arabic version was clearly understood. Researcher designed questionnaire.

A questionnaire was devised by the researchers to gather additional information with regards to improvement in overall family wellbeing and academic performance. Questions regarding academic performance included scores related to reading, mathematics and written expression taken from the NICHQ Vanderbilt assessment scale [59].

3.  Procedure

The parents signed a statement of informed consent and gave medical history as well as completed the SNAP-IV questionnaire during their initial appointment. The student’s teachers completed a pretreatment SNAP-IV questionnaire shortly after the initial clinical appointment. Those children and adolescents who were diagnosed with ADHD were then started on short acting methylphenidate 0.3 mg/kg to the nearest 2.5 mg using 5 and 10 mg tablets or extended-release MPH with doses ranging 18 - 54 mg. Dosages were titrated according to feedback from parents and school reports. Patients were then followed according to the Stimulant Drug Protocol [60]. Around half of them were followed for less than a year and the remaining for more than that. Once done, patients’ parents were asked to fill out the SNAP-IV survey form and researcher designed questionnaire. Statistical analysis

Mean improvement in the score for quantitative variables (inattention score, hyperactivity-impulsivity score, and ADHD Combined score) between the pre-medication SNAP-IV and post medication SNAP-IV were analyzed using paired t-tests and the results were presented with respective p-value and associated 95% confidence interval. Associations between two or more categorical variables were examined using Chi-square test or Fisher exact test as appropriate. All p- values presented were two-tailed, and p values <0.05 was considered as statistically significant.

4.  Results

4.1.   Treatment

Following the confirmation of an ADHD diagnosis, 53.5% of the patients were started on long-acting methylphenidate (Concerta) while 17.2% were prescribed short-acting methylphenidate (Ritalin). Another 16.2% of the patients were started on a combination of long-acting methylphenidate for the day, followed by a dose of short-acting methylphenidate to cover the afternoon time. The remaining 13.1% of the patients were on a combination therapy of methylphenidate and a second non-stimulant medication, which included atomoxetine or antidepressants. (Figures 2-4) provide more information on type, duration and frequency of treatment. Effect of treatment

The six months follow up appointment revealed that 91% of the children had remarkable improvement in their overall academic performance after starting medication as reported by the researcher’s questionnaire. Parents reported based on teachers’ feedback that 88% improved in writing skills, 87% improved in reading skills, and 82% improved in arithmetic as shown in (Figure 5). Furthermore, 84 % reported improvement in their overall family wellbeing, while 85 % reported improvement in behavior as demonstrated in (Figure 6).

SNAP-IV questionnaire-pre and post treatment (Parent questionnaire) in (Table 2) Paired t-test was used to compare mean score between pre and post intervention. The mean inattention score was significantly reduced at post intervention (0.95, +/- 0.46, p < 0.001) compared to pre-intervention (1.96, +/- 0.64, p<0.001). The mean hyperactivity score was significantly reduced at post intervention (0.84, +/- 0.59, p<0.001) compared to pre-intervention (1.54, +/- 0.92, p<0.001). The mean combined score was significantly reduced at post intervention (0.89, +/- 0.48, p<0.001) compared to pre-intervention (1.75, +/- 0.65, p<0.001). Side effects of treatment

Seventy-Five percent of the participants reported side effects after starting treatment. Twenty-seven reported only one side effect, while 45% reported 2 or more side effects and remaining 25% experienced no adverse effects after starting medication. The most common reported side effect was poor appetite in 42% followed by poor sleep in 25% and increased aggression after the medication wore off in 22%. Nineteen percent complained of gastrointestinal symptoms and another 19% suffered from headaches (Figure 7) provides more details about side effects as reported.

Upon comparison of patient characteristics with regards to the likelihood of experiencing side effects, girls were found to be more vulnerable with 80% experiencing one or more side effect compared to 63% of boys however the difference was not statistically significant (p=0.288) due to the small sample size. Patients who were started on both long and short-acting methylphenidate simultaneously were more likely to experience one or more side effects (94%) when compared to their peers who were taking only a single stimulant or any other form of combination therapy, (p=0.345). Seventy-eight percent of the children who were on treatment for less than 3 months experienced side effects. This dropped to around 63% in patients who had been on medication between 3-24 months and increased again to 76.5% among those on medication for more than 2 years. Overall, no statistically significant differences were noted in the side effects between patients in terms of age, gender, diagnosis, or the type, duration and frequency of medication. Results may have been more statistically significant with a larger population. (Table 3) describes this information in detail.

5.  Discussion

The results of this study on the effects of MPH for children and adolescents with ADHD in Qatar government schools demonstrate that children and adolescents who took MPH improved overall in academics, behavior and family wellbeing. Improvement occurred regardless of the prescription whether MPH or combination therapy. These results are consistent with similar international studies [5].

There was marked improvement in symptoms of inattention and hyperactivity when comparing scores for untreated ADHD and after starting treatment at a six month follow up appointment. There was also marked improvement in academics (reading, writing and math) once treatment began. The same was also observed by Daley and Birchwood (2010) [13]. Academic improvement is one of the key targets for measuring the success of treatment for those with ADHD. Previous literature found that those prescribed MPH improved their math and reading abilities [5]. We also know that untreated ADHD results in lower ratings in school subjects on report cards and poorer grades on standardized tests [12]. Although in this study a comparison of standardized grades was not assessed, feedback from teachers and parents reported academic improvements.

Family stress and quality of life due to dealing with a child with ADHD are often reported in the clinic setting. Here we demonstrated significant improvement in family stress and quality of life with improved social functioning outcomes between pre and post-treatment assessments as reported by parents. Thus, it is important for the medical profession to understand that social functioning and family life improves with stimulant intervention for children with ADHD.

Seventy-two percent of participants reported that they experienced side effects after taking MPH whether taking long or short acting medication. It is important to note that females reported more side effects compared to males and patients who were started on a combination of both long and short acting MPH simultaneously experienced more side effects than those who were only started on one MPH. The high rates of side effects experienced in this study are like what was reported by Khajehpiri et al. Seventy-six percent of patients complained of side effects after 6 months of use which indicates the need for a longitudinal study examining the duration of side effects experienced.

Limitations of this study include not using standardized assessments to compare academic improvements pre and post treatment. Additionally, although the SNAP-IV questionnaire is validated, it was not validated on a Middle Eastern population and therefore results may not be generalized.

This study enhanced and expanded on the results other studies found in Qatar regarding children with ADHD [50,55]. It brings forward a condition that is little talked about and often not recognized in this culture and provides Arabic parents with evidence-based resources to access in their own culture when they have questions about treatment for their child with ADHD. It will assist Qatari health professionals in their treatment plan for children with ADHD and may provide some evidence that they need to consider suggesting or offering medical or other treatments for children with ADHD.

Future research needs to be conducted to examine exactly what aspect of educational performance is improved and quantify those with standardized assessments to have more objective goals for family and schools. Ultimately, prescribing MPH seems to improve academic performance by improving attention and behavior in terms of hyperactivity and impulsivity as well as family wellbeing, which all have positive outcomes for the children, parents and the schooling system.

6.  Conclusion

This study showed marked improvement in overall academic performance, quality of life and behavior after starting medication. More than half reported at least one side effect with the most common being decreased appetite and insomnia.

Figure 1: Presenting Symptoms.

Figure 2: Medication Therapy for ADHD.

Figure 3: Duration of Treatment.

Figure 4: Frequency of Treatment.

Figure 5: Improvement in Academics after treatment.

Figure 6: Improvement in Behavior and well-being after treatment.

Figure 7: Side Effects reported by families on medication.

1. Epstein JN, Loren RE (2013) Changes in the definition of ADHD in DSM-5: Subtle but important. Neuropsychiatry 3: 455-458.
2. Willcutt EG (2012) The prevalence of DSM-IV attention-deficit/hyperactivity disorder: a meta-analytic review. Neurotherapeutics 9: 490-499.
3. Centers for Disease Control and Prevention (2018) ADHD Data & Statistics 2018.
4. Rowland AS, Umbach DM, Catoe KE, Stallone L, Long S, et al. (2001) Studying the epidemiology of attention-deficit hyperactivity disorder: screening method and pilot results. Canadian Journal of Psychiatry 46: 931-940.
5. Kortekaas-Rijlaarsdam AF, Luman M, Sonuga-Barke E, Oosterlaan J (2018) Does methylphenidate improve academic performance? A systematic review and meta-analysis, European Child and Adolescent Psychiatry 2018.
6. Van der Kolk A, Bouwmans CAM., Schawo SJ, Buitelaar JK., van Agthoven M, et al. (2014). Association between quality of life and treatment response in children with attention deficit hyperactivity disorder and their parents. Journal of Mental Health Policy Economics.17: 119-129.
7. Dulcan M (1997) Practice parameters for the assessment and treatment of children, adolescents, and adults with attention-deficit/hyperactivity disorder. Journal of American Academy for Child and Adolescent Psychiatry 36: 85-121.
8. Swanson JM, Sergeant JA, Taylor E, Sonuga-Barke EJ, Jensen PS, et al. (1998) Attention-deficit hyperactivity disorder and hyperkinetic disorder. Lancet 351: 429-433.
9. Kessler RC, Adler L, Ames M, Barkley RA, Birnbaum H, et al. (2005). The prevalence and effects of adult attention deficit/hyperactivity disorder on work performance in a nationally representative sample of worker. Journal of Occupational and Environmental Medicine 47: 565-572.
10. Lesesne C, Abramowitz A, Perou R, Brann E (2000) Attention-deficit/ hyperactivity disorder: a public health research agenda 2000.
11. Hakkaart-van L, Roijen BWC, Zwirs C, Bouwmans SS, Tan TWJ, et al. (2007) Societal costs and quality of life of children suffering from attention deficient hyperactivity disorder (ADHD). European Child and Adolescent Psychiatry 16: 316-326.
12. Loe IM, Feldman HM (2007) Academic and educational outcomes of children with ADHD. Ambulatory Pediatrics 7: 82-90.
13. Daley D, Birchwood J (2010) ADHD and academic performance: why does ADHD impact on academic performance and what can be done to support ADHD children in the classroom? Child care health and development 36: 455-464.
14. Van DSJ, Cicek R, Vardar S, Bos JH, de VTW, et al. (2017) Methylphenidate use and school performance among primary school children: a descriptive study. BMC Psychiatry 17: 116.
15. Barry TD, Lyman RD, Klinger LG (2002) Academic underachievement and attention-deficit/hyperactivity disorder: the negative impact of symptom severity on school performance. Journal of School Psychology 40: 259-283.
16. Anastopoulos AD, Guevremont DC, Shelton TL, DuPaul GJ (1992) Parenting stress among families of children with attention deficit hyperactivity disorder. Journal of Abnormal Child Psychology 20: 503-520.
17. DosReis S, Mychailyszyn MP, Myers MA, Riley AW (2007) Coming to terms with ADHD: How urban African-American families come to seek care for their children. Psychiatric Services 58: 636-641.
18. Hamed JH, Taha AZ, Sabra AA, Bella H (2008) Attention Deficit Hyperactivity Disorder (ADHD) among Male Primary School Children in Dammam, Saudi Arabia: Prevalence and Associated Factors. The Journal of the Egyptian Public Health Association 83: 165-182.
19. Owens JS, Goldmine ME, Evangelista NM, Hoza B, Kaiser NM (2007) A critical review of self-perceptions and the positive illusory bias in children with ADHD. Clinical Child and Family Review 10: 335-351.
20. Podolski CL, Nigg JT (2001) Parent Stress and Coping in Relation to Child ADHD Severity and Associated Child Disruptive Behavior Problems. Journal of Clinical Child and Adolescent Psychology 30: 503-513.
21. Wehmeier PM, Schacht A, Barkley RA (2010) Social and emotional impairment in children and adolescents with ADHD and the impact on quality of life. The Journal of Adolescent Health 46: 209-217.
22. Goksoyr PK, Nottestad JA (2008). The burden of untreated ADHD among adults: the role of stimulant medication. Addictive behaviours 33: 342-346.
23. Danckaerts M, Sonuga-Barke EJ, Banaschewski T, Buitelaar J, Dopfner M, et al. (2010) The quality of life of children with attention deficit/hyperactivity disorder: a systematic review. European Child and Adolescent Psychiatry 19: 83-105.
24. Kendall J (1999) Sibling accounts of attention deficit hyperactivity disorder (ADHD). Family process 38: 117-136.
25. Muñoz-Silva A, Lago-Urbano R, Sanchez-Garcia M, Carmona-Márquez J (2017) Child/Adolescent’s ADHD and Parenting Stress: The Mediating Role of Family Impact and Conduct Problems. Frontiers in Psychology 8: 2252.
26. Burd L, Klug MG, Coumbe MJ, Kerbeshian J (2003) Children and adolescents with attention deficit-hyperactivity disorder: 1. Prevalence and cost of care. Journal of Child Neurology 18: 555-561.
27. Leibson CL, Katusic SK, Barbaresi WJ, Ransom J, O'Brien PC (2001) Use and costs of medical care for children and adolescents with and without attention-deficit/hyperactivity disorder. The Journal of the American Medical Association 285: 60-66.
28. Mandell DS, Guevara JP, Rostain AL, Hadley TR (2003) Medical expenditures among children with psychiatric disorders in a Medicaid population. Psychiatric Services 54: 465-467.
29. Silver LB (2009) Attention-deficit/hyperactivity disorder in adult life. Child & Adolescent Psychiatric Clinics of North America 9: 511-523.
30. Secnik K, Swensen AR, Lage MJ (2005) Comorbidities and costs of adult patients diagnosed with Attention-Deficit Hyperactivity Disorder. Pharmacoeconomics 23: 93-102.
31. Swensen AR, Birnbaum HG, Secnik K, Marynchenko M, Greenberg P, et al. (2003) Attention-deficit/hyperactivity disorder: increased costs for patients and their families. Journal of American Academy of Child Adolescent Psychiatry 42: 1415-1423.
32. Swensen AR, Birnbaum HG, Ben HR, Greenberg P, Cremieux PY (2004) Incidence and costs of accidents among Attention-Deficit/Hyperactivity Disorder patients. Journal of Adolescent Health 35: 1-9.
33. Pediatrics (2000) Clinical practice guideline: diagnosis and evaluation of the child with attention-deficit/hyperactivity disorder. American Academy of Pediatrics. Pediatrics 105: 1158-1170.
34. Shier AC, Reichenbacher T, Ghuman HS, Ghuman JK (2013). Pharmacological Treatment of Attention Deficit Hyperactivity Disorder in Children and Adolescents: Clinical Strategies. Journal of central nervous system disease 5: 1-17.
35. Storebo OJ, Krogh HB, Ramstad E, Moreira-Maia CR, Holmskov M, et al. (2015) Methylphenidate for attention-deficit/hyperactivity disorder in children and adolescents: Cochrane systematic review with meta-analyses and trial sequential analyses of randomised clinical trials. The Cochrane database of systematic reviews 25.
36. Baumeister AA, Henderson K, Pow JL, Advokat C (2012) The early history of the neuroscience of attention-deficit/hyperactivity disorder. Journal of the History of Neurosciences 21: 263-279.
37. Advokat C, Scheithauer M (2013) Attention-deficit hyperactivity disorder (ADHD) stimulant medications as cognitive enhancers. Frontiers Neuroscience 7.
38. Freudenheim M (2004) Behavior drugs lead in sales for children. New York Times 17.
39. Arcia E, Fernandez MC, Jaquez M (2004) Latina mothers' stances on stimulant medication: Complexity, conflict, and compromise. Journal of Developmental and Behavioral Pediatrics 25: 311-317.
40. DosReis S, Zito JM, Safer DJ, Soeken KL, Mitchell JW, et al. (2003) Parental perceptions and satisfaction with stimulant medication for attention-deficit hyperactivity disorder. Journal of Developmental and Behavioral Pediatrics 24: 155-162.
41. Brinkman WB, Sherman SN, Zmitrovich AR, Visscher MO, Crosby LE, et al. (2009) Parental angst making and revisiting decisions about treatment of attention-deficit/hyperactivity disorder. Pediatrics 124: 580-589.
42. Charach A, Gajaria A (2008) Improving psychostimulant adherence in children with ADHD. Expert review of neurotherapeutics 8: 1563-1571.
43. Charach A, Skyba A, Cook L, Antle BJ (2006) Using stimulant medication for children with ADHD: what do parents say? A brief report. Journal of the Canadian academy of child and adolescent psychiatry 15: 75-83.
44. Shaw M, Hodgkins P, Caci H, Young S, Kahle J, et al. (2012). A systematic review and analysis of long-term outcomes in attention deficit hyperactivity disorder: effects of treatment and non-treatment. BMC Medical 10: 99.
45. Biederman J, Monuteaux MC, Doyle AE, Seidman LJ, Wilens TE, et al. (2004) Impact of executive function deficits and attention-deficit/hyperactivity disorder (ADHD) on academic outcomes in children. Journal of consulting and clinical psychology 72: 757-766.
46. Biederman J, Monuteaux MC, Mick E, Spencer T, Wilens TE, et al. (2006) Young adult outcome of attention deficit hyperactivity disorder: a controlled 10-year follow-up study. Psychological medicine 36: 167-179.
47. Charach A, Volpe T, Gearing KM, Boydell RE (2008) A theoretical approach to medication adherence for children and youth with psychiatric disorders. Harvard review of psychiatry 16: 126-135.
48. Efron D, Jarman F, Barker M (1997) Side effects of methylphenidate and dexamphetamine in children with attention deficit hyperactivity disorder: a double-blind, crossover trial. Pediatrics 100: 662-666.
49. Haertling F, Mueller B, Bilke-Hentsch O (2015) Effectiveness and safety of a long-acting, once-daily, two-phase release formulation of methylphenidate (Ritalin^® LA) in school children under daily practice conditions. Attention Deficit and Hyperactivity Disorders 7: 157-164.
50. Bradshaw LG, Kamal M (2014) Prevalence of ADHD in Qatari school-age children. Journal of Attention Disorders 21: 442-449.
51. Alhraiwil NJ, Ali A, Househ MS, Al-Shehri AM, El-Metwally AA (2015) Systematic review of the epidemiology of attention deficit hyperactivity disorder in Arab countries. Neurosciences 20: 137-144.
52. El-Nemr FM, Badr HS, Salem MS (2015) Prevalence of Attention Deficit Hyperactivity Disorder in Children. Science Journal of Public Health 3: 274-280.
53. Bishry Z, Ramy HA, El-Sheikh MM, El-Missiry AA, El-Missiry MA (2013) Risk factors for attention deficit hyperactivity disorder in a sample of Egyptian adolescents: a case-control study. Middle East Current Psychiatry 20: 131-139.
54. Alkhateeb JM, Alhadidi MS (2016) ADHD Research in Arab Countries: A Systematic Review of Literature. Journal of Attention disorders 2016.
55. Bener A, Qahtani RA, Abdelaal I (2006) The prevalence of ADHD among primary school children in an Arabian society. Journal of attention disorders 10: 77-82.
56. Rhee SH, Waldman ID (2002) Genetic and environmental influences on antisocial behavior: a meta-analysis of twin and adoption studies. Psychological bulletin 128: 490-529.
57. American Psychiatric Association (2013) Diagnostic and statistical manual of mental disorders Fifth Edition. Washington DC: American Psychiatric Association 2013.
58. Bussing R, Fernandez M, Harwood M, Wei H, Garvan CW, et al. (2008) Parent and teacher SNAP-IV ratings of attention deficit hyperactivity disorder symptoms: psychometric properties and normative ratings from a school district sample. Assessment 15: 317-328.
59. National Institute for Children’s Health Quality (2011) NICHQ Vanderbilt assessment scale. American Academy of Pediatrics 2011.
60. Fischer M, Newby RF (1991) Assessment of stimulant response in ADHD children using a refined multimethod clinical protocol. Journal of child clinical psychology 20: 232-244.