## 4 Discussion  
We have noticed that a significant reduction in overall mean scores has occurred in both groups, but like in some other studies, we found that total mean scores were significantly more reduced in the group treated with psychostimulants [6].  
In the group treated with psychostimulants--Methylphenidate, we noted that there was a significant reduction in symptoms after six months and one year, after treatment, followed by a plateau phase in which the total mean scores remain unchanged.  
In the group treated with Atomoxetine, there was no improvement at one year or two years after the treatment, the mean values of improvement of symptoms being still the same.  
Thus, both types of treatment, psychostimulant with Methylphenidate and non-psychostimulant with Atomoxetine, are effective in improving ADHD [6].  
In the group treated with psychostimulant agents, the level of overall functioning increased significantly more than in the group receiving non-psychostimulant medication especially at six months and at two years from the start of treatment administration [10; 11; 12].  
Today, the medical treatment of ADHD is represented by psychostimulant--Methylphenidate, and non-psychostimulant drugs--Atomoxetine [6; 10; 11; 12]. In the absence of adequate treatment, ADHD has an unfavourable prognosis and may result in complications.  
Thus, it can be said that both types of treatment are effective in reducing the aggressiveness of ADHD symptoms, but psychostimulants bring improvements faster and over a longer period of time [6; 12].  
Therefore, psychostimulants--Methylphenidate, are found to be more effective than non-psychostimulants in ADHD treatment [6; 10; 11; 12].  
Most studies conducted so far suggest that both psychostimulants and non-psychostimulants are effective in treating ADHD. However, it has been found that better and faster results are obtained with psychostimulating therapy [12].  
In a study conducted in 2010, [PERSON] et al. found that the most important improvements observed after administration of psychostimulants refer to the main symptoms of the disorder. Improvements in executive functions, interpersonal relationships, as well as reduced association of behavioural disorders in children with ADHD have also been observed [6,12].  
At the same time, in an open-label study in 2006, [PERSON] et al. suggest that Atomoxetine is as effective as Methylphenidate in treating ADHD, both drugs having very good effects in alleviating attention deficit and hyperactivity/impulsivity [13].  
In 2003, [PERSON] et al. performed eight control studies and six open-label studies to assess the efficacy of Atomoxetine in ADHD patients. An initial 10-week study on ADHD subjects revealed a 30% reduction in total mean scores on Conners Scale, after Atomoxetine administration, compared to 20% representing the drop of total mean scores when a placebo drug was administered. Similar results have been obtained in the case of reduction of the symptoms of inattention and hyperactivity/impulsivity [14].  
Another study, performed by [PERSON] et al., showed the fact, that psychostimulants reduce ADHD symptoms in 70% of the children and adolescents with this diagnosis. At the same time, the study proved that the administration of psychostimulants in childhood determines the reduction of risk of comorbidities onset during adolescence [15].  
In another study, performed in 2010 by [PERSON] et al., during a six months period, it was observed that for 85% of the included subjects, the CGI-I scale scores improved after the administration of Methylphenidate. Moreover, the registered adverse events were minimal [16].  
In 2010 [PERSON] et al. publish a study performed with 67 male subjects, aged between 6 and 13 years, diagnosed with ADHD. They observed through the study that the subjects treated with Methylphenidate had a higher level of language comprehension on the WISC-IV scale (Wechsler Intelligence Scale for Children-IV), in comparison with the subjects, who did not receive psychostimulant treatment [17].