Effect of Risperidone on Cognitive Functions in Adolescents With ADHD and Behavioral Disturbances

Effect of Risperidone on Cognitive Functions in Adolescents With ADHD and Behavioral

Introduction: The use of low dose risperidone and other antipsychotic drugs off-label as augmentation treatment for adolescents with Attention Deficit Hyperactivity Disorder (ADHD) and Disruptive Behavioral Disorder (DBD) has become widely common worldwide, usually to help control behavioral difficulties. While some argue that agents that block dopaminergic receptors may have a deleterious cognitive effect, others stress their moderating effects, which possibly improve function in all domains, including cognitive functions. Only a few studies have examined this topic, with inconclusive results.

Aim of study: To measure the effect of risperidone treatment on various cognitive functions in a population of ADHD diagnosed children and adolescents with normal IQ.

Design: The study is an observational prospective open label clinical controlled trial. The investigators will compare the performance in a battery of cognitive tasks using the Penn Web-Based Computerized Neurocognitive Battery (WebCNP) and the IGT, in children and adolescents diagnosed with ADHD, with and without risperidone.

Study population: Children and adolescents diagnosed with ADHD, 8-17 years old, may be eligible for this study. We will recruit subjects who their psychiatrist is considering rispieridone treatment, those who are already treated with risperidone and subjects with only stimulants treatment. All pharmacological treatment is supervised and prescribed to subjects by their personal psychiatrist unrelated to the study.

Significance: Better knowledge of the specific cognitive effects of this form of therapy will help us guide both clinical decisions, and recommended monitoring in daily clinical work.

Study Purpose: To evaluate the effect of atypical antipsychotic augmentation, specifically risperidone on specific cognitive domains in adolescents with ADHD and behavioral disturbances.

Hypotheses:

1. Risperidone will improve performance in tasks assessing attention, verbal memory, visual memory and working memory in adolescents with ADHD and DBDs
2. Risperidone will impair performance in tasks assessing spatial memory and some executive functions in adolescents with ADHD and DBDs.
3. Risperidone, but not other atypical antipsychotic, will improve performance on the IGT.

Study Design

General:

This study is an observational prospective open label clinical controlled trial.

The planned study will compare performance, with and without the effect of risperidone, in various cognitive tasks in children and adolescents diagnosed with ADHD.

Each subject will perform a battery of cognitive tasks using the Penn Web-Based Computerized Neurocognitive Battery (WebCNP) and the Iowa Gambling Test (IGT).

Experimental Procedure

Each potential subject and his parents will be screened on the phone for the study. All enrolled subjects will be instructed to avoid taking any stimulant treatment on the days of assessment sessions. On the day of enrolment, each subject will be evaluated by a standard basic medical interview and physical and neurological examinations for evidence of current neurological and physical disorders. They will also be evaluated by the Development and Well-Being Assessment (DAWBA) for evidence of any psychiatric disorders. Parents will also answer DAWBA questionnaire. Subjects who will qualify for the study and their parents will receive a comprehensive explanation on the study and will sign an informed consent form. Subjects will then complete The Penn Web-Based Computerized Neurocognitive Battery (WebCNP) and the Iowa Gambling Test (IGT). The first session will take approximately 2.5 hours. All subjects will undergo a follow up session approximately a month after the first session. The second session will take approximately 2 hours. Subjects in Groups II will be instructed to start taking their risperidone after the first session and on the day of the follow up session. Subjects on Group III will be instructed to take their risperidone or other atypical antipsychotic treatment on days of the experiment in the night before the session at least 8 hours before the sessions and in the month between them. The treatments with Risperidone will be given only according to the decision and guidance of the subject's physician. All subjects will be invited to perform the Penn Continuous Performance Test for a third time, under the influence of their stimulant treatment. Normal IQ will be ascertained using the Raven's Progressive Matrices task which is a part of the WebCNP battery.

Inclusion Criteria:

• Male children and adolescents diagnosed with ADHD Age: 8-17 years.
• Psychiatric comorbidities including: Major Depressive disorder, General Anxiety Disorder, Panic Disorder, Obsessive Compulsive Disorder, Oppositional Defiant Disorder, Conduct Disorder, Disruptive Dysregulation Mood Disorder, Intermittent Explosive Disorder and all phobias.

Exclusion Criteria:

• Any current serious medical or surgical illness.
• History of a major neurological illnesses (including brain injury).
• Psychiatric comorbidities including: All psychotic disorders, Bipolar Disorder and personality disorders.
• History of alcohol or substance abuse.
• Intellectual disability: Total IQ< 70