Objectives: The objective of this research was to explore the effects of risperidone on DB in subjects with autism for period of time of one year.
Methods: 47 subjects with autism were included, medicated with risperidone for one year. Drug effectiveness in DB was evaluated using Autism Treatment Evaluation Checklist (ATEC) at baseline and at defined times (T) after start of risperidone therapy (1, 3, 6 and 12 months). The reduction in average scores indicates significant clinical improvement. Inclusion criteria were: diagnosis of autism (ADI-R/ADOS positive results); no profound intellectual disability (Global Intellectual/Developmental Quotient>35 or mental age>18months); severe DB with no response to non-medication treatments (presence of two or more DB with Moderate Problem or Serious Problem classification at ATEC: sleep problems; hyperactive; hits or injures self; hits or injures others; destructive; anxious/fearful; shouts or screams; often agitated); without any psychotropic medications for at least 3 months. Statistic analysis (SPSS17) was performed comparing the variation of scores in each assessment times with ANOVA or Friedman repeated measures tests. Significance level(σ)=0.05.
Results: 39 of 47 (83%) subjects completed one year of medication with risperidone (30M/9F:3.3/1). Although the mean risperidone dose was increased progressively throughout the year, the largest increase was found from the 3rd (1,29±0,71mg/day) to the 6th month (1,36±0,66mg/day). There was a significant progressive reduction in the global average score of ATEC in T1,T3,T6,T12 after baseline (T0), beginning with a score=68.87 (T0) to a minimum=33.87 (T12). This improvement score was 51% and showed statistical significance (ρ<0.0001). The average scores in subscales of ATEC (I-Speech;II-Sociability; III-Sensory/Cognitive Awareness; IV-Health/Physical/Behaviour) have revealed significant changes over the year of treatment (T0-T12:ρ<0.0001), this improvement was more evident in subscale-IV. The reduction in the average score of disruptive behaviour during the T0-T1 of medication (T0=23.44 to T1=12.1) was 48%. The decrease in DB continued to register until T12, showing an improvement of 73%. In the Subscales I, II and III improvement between T0-T12 was 34%, 49% and 31%, respectively.In any of the cases excessive sedation or extrapyramidal side-effects were verified.
Conclusions: These findings demonstrate that risperidone, in low doses and with minor adjustments, can rapidly improve some symptoms often associated with autism, particularly in the DB. This benefit, which occurred as early as T0-T1 of treatment, was increased over a year. There was also a significant improvement in the other subscales, but on a lower degree. As in other previous studies, the results obtained confirm the rapid efficacy of risperidone in the treatment of DB in autism, maintaining a positive response in the long term which discourages its suspension.