The purpose of this program is to: (a) meet the demands of families for the improvement of the educational attention to students with ADHD; (b) improve teacher training and effectiveness of teachers, orientation teams, and Education Inspection teams; (c) implement strategies and resources to adapt the educational proposal to the students' needs; (d) channel all investigations or actions carried out, which requires the supervision of the Council of Education or the Council of Health; (e) facilitate coordination with the Council of Health to determine procedures and instruments for the detection, identification, and intervention; and, finally, (f) identify these students and their interventions, using specific norms, and specify the actions of Council of Education and Health of the Government of the Canary Islands (Spain).

In order to design, implement, evaluate, and model programs and materials for intervention with students with ADHD, we propose to carry out experimental workshops for these students. The following workshops are planned: (a) development of executive functions: stimulation of attention, working memory, planning, etc.; (b) stimulation of intellectual skills: logical, mathematical, and verbal reasoning contextualized in the curricular areas; (c) development of skills for independent learning: study techniques (study environment, well organized study, underlining, summarizing, outlining, memorizing) and planning; and (d) development of social competence: basic social skills, interpersonal problems, assertiveness, etc.

Within this program of comprehensive care for students with ADHD and their families developed by technicians of the Government, it was considered appropriate to study the anxiety level perceived by the children and by their parents, because numerous studies of children and adolescents with ADHD show that their functioning is similar in many domains, including comorbidities with behavioral disorders, anxiety, and school problems (Colomer-Diago et al., 2012). Children with ADHD have a higher rate of symptoms of anxiety and depression than typically developing children or children with learning difficulties (Biederman et al., 1996). The comorbidity of ADHD with anxiety is estimated between 20-25% on average (Barkley et al., 1997; Michanie, 2000). In the study carried out by Shea et al. (2014), this percentage is 27.5, and of these, more than 50% presents comorbidity with oppositional defiant disorder or conduct disorder.

The key conclusion in the study of Colomer-Diago et al. (2012) confirms the importance of children's stressful characteristics as a risk factor, showing the relationship between psychopathology and personal characteristics such as high negative emotionality or low control of effort (Muris and Ollendick, 2005). In the study of López-Villalobos et al. (2004), the results show that children with ADHD present alterations in academic, relational,  family, and clinical dimensions.

The anxious child tends to display a permanent state of worry or apprehension that is difficult to control, and, sometimes, parents do not perceive their child's anxious feelings (Artigás-Pallarés, 2003).

Abad-Más et al. (2013) propose that psychopedagogical interventions should consider individualized treatment within a multidisciplinary methodology, always taking into account the children’s context, their academic performance, and the appropriate pharmacological interventions for each case. There are also programs aimed at minimizing aggressiveness, improving self-esteem and social problems, as well as for anxiety and depression. These intervention strategies should be combined with training in executive functions (Abad-Más et al., 2011; Miranda et al., 1997) or curricular adaptations (if necessary) to improve children's cognitive and academic skills.

On the other hand, Tai et al. (2012) conclude that the sooner ADHD is identified and treated, the greater the possibility of controlling subsequent anxiety. Comorbidity between ADHD and other disorders, including anxiety, mainly affects the family and risk activities in adulthood (dangerous driving, illegal behaviors, substance abuse, and inappropriate sexual behavior). Therefore, the results obtained by Miranda et al. (2014) illustrate the importance of developing a multimodal approach to help adults with ADHD to deal with the associated comorbid disorders, offering them support in the organization of daily activities, and incorporating the family in the treatment plan.

Participants

Participants were 76 students enrolled in primary education or compulsory secondary education, 62 boys and 14 girls (Table 1). Mean age is 11.15 years (SD = 1.79; age range 8 to 15 years). One parent of each child participated, 76 in total, 33 fathers and 43 mothers. The parents' mean age was 43.54 years (SD = 6.74; age range 30 to 59 years). The sample was extracted from the population of students participating in the above-mentioned "Program for educational attention to students with ADHD" (Table 1).

Instrument

The SCARED in its 41-item version (Birmaher et al., 1999) is a self-report developed to assess a wide range of symptoms of anxiety in children from the general population according to the DSM-IV-TR (APA, 2000). It was adapted to the Spanish population by Domènech-Llabería (2002). In most adaptations, an internal five-factor structure was found, as in the original version (Birmaher et al., 1999): Panic/Somatic (PN), Generalized Anxiety (GD), Separation Anxiety (SP), Social Phobia (SC), and School Phobia (SH). In all the studies, the psychometric properties of the four scales related to the anxiety disorders of the DSM-IV-TR are high (Hale et al., 2011) but School Phobia provides controversial results (Doval et al.,  2011). Each item rates each symptom frequency over the past three months on a scale ranging from 0 to 2 points. The total score can range from 0 to 82.

Hale et al. (2011) performed a meta-analysis of the cross-cultural psychometric properties of the Screen for Child Anxiety Related Emotional Disorders (SCARED). Studies were collected from the PsycINFO, PubMed, SSCI, SCI-Expanded, ERIC, and A&HCI databases from the year of the SCARED's first publication (1997) to the present. The inclusion criteria focused on all studies that examined the psychometric properties of the SCARED. Twenty-one articles were retained, reporting a total of 25 studies predominantly from Europe (Belgium, Germany, Italy, the Netherlands) and the USA, as well as South Africa and China, that matched the authors' inclusion criteria. It was found that the psychometric properties were robust for the SCARED scales related to the symptoms of the Diagnostic and Statistical Manual of Mental Disorders-IV-TR criteria for anxiety disorders, that females scored significantly higher than males, and that age had a moderating effect on sex differences in the scores. This meta-analysis suggests that the SCARED can be utilized as a screening instrument for DSM-IV-TR anxiety disorder symptom dimensions for children and adolescents from various countries.

Design and procedure

The questionnaires were applied by the researchers in the closing session of the 2013/2014 course of the above-mentioned program. The students received a copy of the questionnaire and precise instructions on how to complete it in the workrooms. On the same day and time, their parents completed the version for parents of the questionnaire in another classroom. Previously, the parents had received a formal written invitation to participate in the study. The participation of parents and students was voluntary. 

Figure 1 presents the mean scores (standardized on a scale from 0 to 2) of each of the factors of the SCARED separated by gender. It can be seen that the perception of anxiety was always higher in mothers than in fathers. Likewise, girls' scores tended to be higher than boys' scores in all the factors except for Panic/somatic.

Symptom prevalence was calculated from the cutoff points of the SCARED (≥25). Thus, it was observed that 49.2% of the boys were above this cutoff point compared with 57.1% of the girls. In the case of the parents, their perception of their children's anxiety shows that 50% of the fathers scored higher than the cutoff point of the SCARED (≥25) compared to 72.5% of the mothers.

No   significant   differences   between  boys’  and  girls' means were found either in the total score or in any of the factors (Table 2). However, the girls' mean in all the factors, including the total score, was higher, except for the Panic/Somatic factor, where the boys' mean score was higher.

Significant differences between mothers and fathers were only found in Generalized Anxiety (p < .015). In this case, the mothers' perception of anxiety was higher, with a mean of 10.23 versus the fathers' mean of 7.97 (Table 3). In all the factors, including the total factor, the mother's mean score was always higher than that of the fathers.

The mean difference between boys/girls and parents in the total anxiety score was significant (p < .011). The parents obtained a total mean score of 30.71 versus the children's total mean score of 25.37 (Table 4). There was also a significant mean difference between the children and the parents in Generalized Anxiety (p < .000), where the parents reached a mean score of 9.25 versus the children's mean score of 7.03. In the remaining factors, no significant differences were found, although the parents' perception of anxiety was always higher than that of the children.

Analysis of the correlations between factors (Table 5) revealed differences in the number of significant correlations depending on the type of participant (children or parents) and on their gender (boy or girl, father or mother).

The Panic/Somatic Factor had significant correlations with the rest of the factors, especially in the boys, fathers, and mothers. In particular, in the boys, the correlation varied between r = .706 with Separation Anxiety and r = .449 with Social Phobia. In the fathers, the correlation ranged from r = .779 with School Phobia to r = .370 with Social Phobia. In the case of mothers, the correlation varied from r = .675 with School Phobia to r = .367 with Social Phobia. Lastly, in the case of the girls, significant correlations were only found with the factors of Generalized Anxiety (r = .681) and Separation Anxiety (r = .552).

The Generalized Anxiety Factor also showed significant correlations with the remaining factors in boys and mothers, but not with Social Phobia in fathers, and only with School Phobia in girls (r = .601) in addition to the above-mentioned   correlation   with    Somatic/ Panic (r = .681).

In the case of the boys, the correlation ranged from r = .705 with Separation Anxiety to r = .387 with School Phobia. In the case of the mothers, the correlation varied from r = .542 with Separation Anxiety to r = .372 with Social Phobia factor. Finally, in the case of the fathers, the correlations of  this  factor  ranged  from r = .626  with Separation Anxiety to r = .472 with School Phobia. There was no significant correlation with Social Phobia.

The Separation Anxiety factor had significant correlations with Social Phobia and School Phobia in boys and mothers but only with School Phobia in fathers (r = .578), in addition to the above-mentioned correlations with the Panic/Somatic (r = .726) and Generalized Anxiety factors (r = .626). No significant correlations were observed in girls, except for the above-mentioned correlation with the Panic/Somatic factor (r = .552). In the specific case of the boys, the correlation varied between r = .706 with Panic/Somatic and r = .387 with School Phobia. In the case of the mothers, the correlation ranged between r = .578 with Panic/Somatic and r = .372 with Social Phobia.

Lastly, Social Phobia only had significant correlations with School Phobia in boys (r = .398), in addition to the above-mentioned correlations with Panic/Somatic (r = .631), Generalized Anxiety (r = .387), and Separation Anxiety (r = .539). In the case of the girls, the mothers and the fathers, no significant correlations between this factor and School Phobia were found.

Table 6 shows the correlations between the factors assessed by the SCARED and the participants' age. Although no correlation was significant, it can be observed that both in girls and boys, the scores on the different factors have a small negative correlation with age: the older the children, the less anxiety, and vice versa. On the other hand, in the parents, there was a small positive correlation  between  the  SCARED  factors  and  parents' age, indicating that the older the parents, the more anxiety they perceived, and vice versa. This relationship is more evident in the factor of School Phobia. 

In accordance with several authors (Muris et al., 2002; Romero et al., 2010; Sandoval et al., 2006; Wren et al., 2004), in our study, the girls present more symptoms of anxiety on the SCARED than the boys, although these differences were nonsignificant. The lack of significant differences found in our study in this respect may be due to the sample size (only 14 girls versus 62 boys). If the number of girls were increased, the mean differences would probably be significant in favor of the girls in all the factors of the SCARED except for the Panic/Somatic Factor, the only factor where the boys'  mean  score  was higher than that of the girls.

Similarly, the mothers perceive higher values of anxiety than the fathers in all the SCARED factors, but this difference was only significant in the Generalized Anxiety Factor. However, in the Global Anxiety score, there were more than 20 points difference between mothers and fathers. Compared to 50% of the fathers who exceeded the cutoff point of the SCARED (≥25), 72.5% of the mothers exceeded this point.

In all the factors, the children's anxiety levels as perceived by their parents were higher than the children's own perceptions, although these differences were only significant in the global SCARED score and in the Generalized Anxiety Factor.

Regarding the differences between boys, girls, mothers, and fathers, it can be concluded that the SCARED cutoff point (≥25) was exceeded by 49.2% of the boys, 50% of the fathers, 57.1% of the girls, and 72.5% of the mothers, indicating considerable similarity between the boys and the fathers, with moderate values, higher levels of anxiety in the girls, but above all, a greater perception of anxiety in the mothers.

Although anxiety disorders are characterized by homotypal (prediction of the disorder by the same disorder) and heterotypal continuity (prediction of the disorder by another disorder), certain anxiety disorders appear to covary more than others (Gregory et al., 2007). The Panic/Somatic and Separation Anxiety Factors show a close developmental relationship, called the separation anxiety hypothesis (Klein, 1964; Silove et al., 1996). The two factors share common physiological disturbances, such as somatic symptoms (Pine et al., 2005; Slattery et al., 2002).

In our study, we found multiple significant correlations between all the factors of the SCARED in the boys. In the case of the girls, there were fewer significant correlations between the SCARED factors: only between the Panic/Somatic Factor and the Generalized Anxiety and the Separation Anxiety Factors, as well as the correlation between the Generalized Anxiety Factor and the School Phobia Factor.

In the case of the fathers, the number of significant correlations between factors was notable, although not generalizable to all the factors. The Social Phobia Factor had the fewest interactions with the other factors.

Lastly, in the case of the mothers, the number of significant correlations was also fairly remarkable but again, not generalizable to all the factors. There was no correlation between the Social Phobia Factor and the School Phobia Factor.

It can therefore be concluded that there is a trend towards multiple significant interactions among factors in the boys. Also, in the case of the fathers and mothers, multiple significant interactions among factors emerged, with a few exceptions related to the School Phobia and Social Phobia Factors. The girls show a lower number of interactions between the SCARED factors; again, the sample size (only 14 girls) may be an explanation for this difference with the remaining participants.

In terms of age, although not significant, the correlations between age and the different factors measured by the SCARED indicate that, as the boys' and girls' age increases, the values of anxiety decrease. Conversely, the older the parents, the higher the levels of perceived anxiety in all the factors, especially in School Phobia. Similarly, other authors (Birmaher et al., 1997; Compton et al., 2000; Essau et al., 2002; Hale et al., 2005; Ogliari et al., 2006; Su, Wang et al., 2008) point out that, regarding age differences, the results indicate that although separation anxiety decreases as the adolescent matures, other anxiety disorders increase with age.

The results of our study should be interpreted in the light of its limitations. One of them is the small sample size (N = 76), made up only of children and adolescents who   voluntarily  attend   the   "Program   for  educational attention to students with ADHD" of the Council of Education of the Government of the Canary Islands, although most of those diagnosed by the psycho-pedagogical orientation services of the public centers attend this program. Another limitation was that, to diagnose anxiety, we did not carry out a structured interview, but instead, it was measured by means of the self-reports performed by the children and adolescents and their fathers and/or mothers through the SCARED.

Few studies have used the information gathered by parents' self-reports about the anxiety that their children suffer. Thus, Magiati et al. (2014), using the Spence Children’s Anxiety Scale Parent Version (SCAS-P) and the Child Self-report (SCAS-C), found that there was agreement between caregivers and children about the anxiety symptoms shown by the latter. Similar results were found in several studies (Li et al., 2011; Nauta et al., 2004; Whiteside and Brown, 2008) performed in Australia, Hong Kong, and the United States, respectively, using the same instrument, with normally developing youngsters with and without anxiety disorders.

Early identification of the possible comorbidities between ADHD and anxiety disorders is very important for the quality of life of adults with ADHD, in order to treat and reduce their negative effects, as various cited studies have proposed (Miranda et al., 2014; Tai et al., 2012).

We wish to thank the General Direction of Organization, Innovation and Educational Promotion of the Council of Education, Universities and Sustainability, Government of The Canary Islands (Spain), which is responsible for the Program for the Educational Attention to Students with ADHD.

The authors have not declared any conflict of interests.