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INTRODUCTION: Mental retardation (MR) is a lifelong and chronic impairment which has problematic medical, social, educational and economic aspects. The combination of mental and physical disorders associated with mental retardation is higher than that of the community average. Early diagnosis and appropriate treatment are very important for increasing patients’ functionality and quality of life1 . The present study aims to examine the sociodemographic characteristics, admission complaints, the level of MR, accompanying comorbidities, the prevalence of psychotropic medication use, the medications used and the predictors of psychotropic medication in children and adolescents aged 6-18 years and diagnosed with mental retardation.
METHODS AND MATERIALS: In this study, hospital records of outpatient cases attending the Child Psychiatry of Ankara Pediatric Hematology Oncology Training and Research Hospital in the six-month period between June and December 2013 were screened retrospectively. Detected cases with mental retardation aged 6-18 years were evaluated in detail. In this evaluation, the sociodemographic characteristics, the level of mental retardation, the first presentation complaints, the psychiatric and medical history of the patients, the presence of comorbidity and drug use variables were examined. Psychiatric diagnoses were classified according to DSM-IV-TR. For measuring the intelligence quotient (IQ), Weschler Intelligence Scale for Children-Revised (WISC-R) and Stanford Binet Intelligence Scale were used. Thus, MR subtypes were defined according to the full-scale IQ score as the following; IQ=50-69 as mild MR; IQ=36-49 as moderate MR; unknown but presumed IQ score 0.05). Similarly, no significant difference was detected between children and adolescents in gender terms. Males represented 60% of all subjects (n=943). Male/female ratio was almost 1.5 (M/F=1.49). Classification of MR subtypes was the following: More than half of the whole sample (57.3%) had mild MR, 15.5% of all had moderate MR, 14.8% of all had severity unspecified MR, 12.2% of all had severe MR, and 0.3% of all had profound MR. Evaluation of the patients’ complaints revealed that the most common cause for presentation was school failure (37.7%). The others were the following: renewal of special education report, aggressive and/or violent behavior, speech delay or retardation, hyperactivity and/or attention deficit, objections to the special education reports arranged before, avoidant and/or anxious behavior, and other reasons. In this sample, 26.1% of all MR (n=410) were newly diagnosed cases of MR. In 3.1% of the sample (n=48), the diagnosis of mental retardation was changed to “borderline intellectual functioning (IQ=70-79) plus specific learning difficulties”. At least one psychiatric comorbidity was detected in 24.6% of all cases; most commonly found were disruptive behavior disorders (DBD; including conduct disorder (CD), attention deficit hyperactivity disorder (ADHD), and CD plus ADHD; 14.2%). The others were pervasive developmental disorders (PDD), anxiety disorders, elimination disorders, mood disorders and tic disorders. Non-psychiatric comorbidities accompanying MR were found as 49.7% of the entire sample. Amongst these, the most frequently identified one was epilepsy (21.9%), followed by cerebral palsy (CP) and speech and/or hearing impairment, respectively. Evaluating of the relationship between MR levels and epilepsy showed that epilepsy presence in all five MR subtypes was found significant (χ2=227.845, p<0.001), prominently with profound MR (80%) and severe MR (61.3%). Having epilepsy in profound and/or severe MR cases was significantly higher than that of the other MR patients (χ2=206,937, p<0.001). The relationship between MR level and CP was also evaluated, revealing that CP prominently accompanied 80% of profound MR and 60.2% of severe MR. It was also detected that profound and/or severe MR cases display CP comorbidity significantly more than other MR patients (χ2=278.320, p<0.001). When the relationship between MR levels and speech and/or hearing impairment comorbidity was evaluated, it was found that speech and/or hearing impairment accompanied mostly the 12.5% severity unspecified MR and 10.6% of those with mild MR. It was determined that having speech and/or hearing impairment comorbidity in mild MR, moderate MR and unspecified MR, in favour of unspecified MR (12.5%), was significantly more common than in profound and/or severe MR cases (χ2=14.117, p<0.001). Evaluation of the clinical features of the MR cases in terms of gender revealed that having any of psychiatric disorders and having pervasive developmental disorder were significantly more likely in males than in females (χ2=7456, p=0.006; χ2=15.669, p<0.001, respectively). Psychotropic medication used in children and adolescents with MR showed that 79.6% of the sample (n=1252) had not received any kind of psychotropic medication, whilst 20.4% of all had been using at least one psychotropic drug. Of these, 16.7% (n=262) had been using one psychotropic drug and 3.7% (n=58) were using combined pharmacotherapy. When assessing the distribution of psychotropic medication use, it was observed that the most commonly used psychotropic drugs were “antipsychotics” (14.2%, n=219), the most frequently used agent being risperidone (11.5%, n=180). The second-most commonly used agents were those for ADHD treatments (5.6%, n=89), including methylphenidate (MPH; 4.6%, n=72) and atomoxetine (ATX; 1.0%, n=17). The third-most preferred agents were selective serotonin reuptake inhibitors (SSRIs; 3.8%, n=57), with fluoxetine being the most preferred substance (3.4%, n=52). Analysis of the predictors of psychotropic medication use revealed that comorbid psychiatric disorders presence, having ADHD, having CD and having anxiety disorders were detected as predictors (p<0.001, Beta=0.029, 95%Cl [0.011-0.080]; p=0.002, Beta=0.190 95%CI [0.066-0.545]; p<0.001, Beta=0.088 95% CI [0.030-0.257]; p<0.001, Beta=0.029 95%CI [0.011-0.233], respectively).
DISCUSSION: In this study, we examined children and adolescents with MR in terms of their clinical characteristics, psychotropic medication use and the predictors of pharmacotherapy. In a six-month period, we found that MR is 1.5 times more frequent in males than in females. All levels of mental retardation have been more frequently described in the literature in the male gender. In a study conducted in a university hospital in Turkey, it was detected that 60.3% of 209 cases diagnosed with MR were male, and 39.7% were female2 . In another study, it was detected that 73% of 200 cases diagnosed with MR were male and 27% female3 . In our study, about two thirds of the cases were male, which is consistent with the literature. Although there is no clear evidence, the presence of mental retardation syndrome associated with the X chromosome and boys being more sensitive to certain diseases such as neonatal sepsis could be causes of these conditions. In the literature, it was stated that 85% of all MR cases are mild MR, 10% moderate MR, 4% severe MR, and 1% profound MR; these rates could vary according to age, socioeconomic factors and cultural structure1 . In our study, it was found that mild MR was the most frequently found group. However, unlike in the literature, in our study it was seen that unspecified MR (14.8%) was the third-most common group. The probable explanation for this situation could be difficulties in evaluating the intelligence level of cases with hearing and/or speech disorders who constitute 9.4% of the total sample. In a study conducted in Turkey2 the prevalence of epilepsy in patients with mental retardation was 28.2%, similarly to the rate of 21.9% we found in our study. In the literature, it was reported that the prevalence of epilepsy is 0.7% in the normal population, 3-6% in patients with mild MR, 23% in moderate MR and 50% in severe MR3 . In our study, it was determined that there was a significant correlation between the incidence of epilepsy and MR level. Profound and/or severe MR in patients with epilepsy were often found to have significantly higher incidence of epilepsy than that seen at other intelligence levels. It was consistent with findings of previous studies that the MR level increases along with an increase of the frequency of epilepsy3 . Another clinical situation that was often associated with mental retardation was CP. In a study conducted with MR cases in Turkey, CP frequency seen in these cases have been reported at a rate of 14.4%2 . The prevalence of CP in our study was found to be 17.9%, which was similar to this finding. It was reported that 10-15% of cases with MR have visual impairments and 10-15% have hearing problems4 . Similar with these reports, in our study we found that speaking and/or hearing impairment was found in 9.4% of the cases. Psychopathologies accompanying mental retardation are also seen at high rates in these patients because of their environmental features, as they have more exposure to adverse socioeconomic conditions, and this was linked to an increased psychopathology risk1 . In our study, the incidence of psychiatric comorbidity was determined as 24.6%. Similar to findings of a study conducted in Turkey3 , in our study psychiatric comorbidity was significantly more frequent in mild MR than in other subtypes of MR. This may result from a high level of presence of mild MR in our sample. There is a possibility of insufficient sensitivity of tools and methods which we used in the diagnostic process, as the mental retardation level increases and difficulty in the diagnosing process or in patients who, due to severe clinical symptoms of MR, may have more limited verbal ability and more difficulty to explain their complaints. A study conducted in Turkey reported that 79.4% of male patients with MR and 46.2% of the females have a psychiatric comorbidity3 . Similarly, in our study, psychiatric comorbidity was found in 65.9% of males and 34.1% of females, which was statistically significant in favor of males. The most frequently identified psychiatric comorbidities in MR were reported as PDD, ADHD, anxiety disorders, mood disorders, psychotic disorders, personality disorders, conduct disorder, posttraumatic stress disorder, tic disorders and eating disorders3 . In our study, MR comorbid diseases were found to be DBD, PDD, anxiety disorders, elimination disorders, mood disorders, and tic disorders, in order of frequency, and the comorbidity rates were generally lower than in the literature. The cross-sectional nature of our study and its being performed retrospectively may have led to this situation. In the United States, 30-75% of all cases with MR were reported to have been prescribed psychotropic drugs5 . In a study conducted in Turkey, 62.5% of patients with MR were found to use any psychotropic drug3 . Psychotropic drug use was found to be 20.4% in the MR cases in our sample, and we thought that this ratio is relatively low, compared to the above-mentioned rates, due to the lower comorbidity we found. Most commonly used pharmacological agents in this area were reported as antipsychotics, benzodiazepines, lithium, antiepileptics, tricyclic antidepressants, and SSRIs3,5. Likewise, in our study the most commonly used psychotropic drugs were antipsychotics, followed by MPH, ATX, and SSRIs. In our sample, given that the most common comorbidity found was DBD, this may have affected MPH and ATX use rates, which were different from the literature
CONCLUSION: Our study has the characteristic of a situation determination associated with cases who attended child psychiatry and were diagnosed with MR. The most important limitation of our study is that the evaluation was made retrospectively. The relatively large size of the sample is the most important advantage. There is a need for studies with more detailed information, designed as a prospective, multicenter study with a large sample size, to draw up a way of health policies related to children and adolescents with MR in Turkey. This type of studies in the future will provide a more comprehensive evaluation of cases with MR and intervention attempts which should continue lifelong from the early stages.