Introduction
Asperger syndrome is a form of Autism Spectrum Syndrome with generally higher functioning and better cognitive skills. Autism, also referred to as autism spectrum syndrome, is a developmental syndrome that can cause severe and pervasive impairment in thinking, feeling, communication, and interaction with others. Signs of autism appear at a very young age of 2-3 years. Still, associated development delays can be diagnosed as early as 18 months with symptoms of repetitive behaviors or interests and deficits in social interaction, verbal communication, and nonverbal communication. Sensory sensitivities and medical issues such as gastrointestinal syndromes, seizures, or sleep syndromes with anxiety, depression and attention issues are other factors associated with autism.
Asperger was added to the American Psychiatric Association’s Diagnostic and Statistical Manual of Mental Syndromes (DSM-IV) in 1994 as a separate syndrome from autism and replaced by Autistic Syndrome, Asperger syndrome and other pervasive developmental syndromes with the umbrella diagnosis of autism spectrum syndrome in 2013.
People with Asperger’s may be socially awkward and have an all-absorbing interest in specific topics with good rote memory skills but problematic ideas about abstract concepts.
What distinguish Asperger syndrome from classic autism are its less severe symptoms and the absence of language delays. Children with Asperger syndrome may be only mildly affected and frequently have good language and cognitive skills.
Key points about Asperger Syndrome
- It affects boys and girls equally, though more difficult to diagnose in girls.
- Can be subject to meltdowns
- Face difficulty in understanding non-verbal stimuli and in interpreting the feelings, thoughts and motives of others
- Experience sensory difficulties
- Motor difficulties in the form of inability to execute a sequence of actions, atypical eye movement and deficiencies in motor learning
A word about Atomoxetine and Asperger
Atomoxetine is an FDA-approved medication used in the treatment of ADHD in children. It belongs to a class of drugs called selective norepinephrine reuptake inhibitors that work by increasing the levels of norepinephrine, a natural substance in the brain that is needed to control behavior.
With regard to ADHD and Asperger’s, the symptoms often overlap, making it difficult to make a diagnosis. Studies have proved that 60-70 percent of children with Asperger syndrome have signs compatible with an ADHD diagnosis, sometimes making it even more difficult for clinicians to diagnose the exact condition and initiate adequate treatment protocols.
Diagnosis and Statistical Manual of Mental Syndromes has regulated that a diagnosis of ADHD cannot be given along with a diagnosis of Autistic syndrome. But when ADHD symptoms are present in Asperger syndrome and respond to psychostimulants, it becomes easier for clinicians to provide relief to the patient.
It has been observed that many children with Asperger Syndrome do not have a favorable response to stimulants like Methylphenidate or amphetamines, whether administered individually or in concomitant form. Some children even exhibit increased adverse reactions in the form of tics or increased repetitive behaviors to amphetamine use. Researchers explain the phenomenon to be accelerated by anxiety and advise conventional ADHD medications as a comorbid treatment option.
Atomoxetine is one such ADHD medication effective as adjunctive therapy for the comorbid ADHD associated with Asperger syndrome. It is important to understand the mechanism of Atomoxetine to understand the medication’s effectiveness better.
Several neurotransmitters are responsible for dampening or facilitating cellular activities in the brain. Studies have shown that the concentration of neurotransmitters is different in Asperger’s and influences the brain functioning pattern. A higher level of N-acetyl aspartate/choline (NAA/Cho) in Asperger is found in the right anterior cingulated cortex. It is responsible for various cognitive functions, including emotional expression, attention allocation, and mood regulation. In addition, F-Dopa influx(k) – an assessment parameter for the dopamine system – increase in the striatum, putamen, caudate nucleus, and frontal cortex indicates involvement of the dopaminergic system in the condition.
Dopamine in the dorsal striatum contributes to the sensorimotor coordination of consummatory behavior and develops a ‘response set’ in motor preparatory processes for skilled responses. Putamen is enriched with dopamine and associated with dopamine-related phenotypes, including neuropsychiatric and neurodegenerative syndromes that manifest with motor impairment, impulsive behavior, and cognitive deficits.
Inhibition of the presynaptic norepinephrine transporter by Atomoxetine prevents the reuptake of norepinephrine throughout the brain. It inhibits dopamine reuptake in specific brain regions, such as the prefrontal cortex, where dopamine transporter (DAT) expression is minimal. An increase in dopamine levels improves the desired cognitive and psychological balance and enables the individual’s normal functioning.
Can Atomoxetine help people with Asperger syndrome?
In a study conducted to evaluate the effectiveness of Atomoxetine for hyperactivity in autism spectrum syndromes, children aged five to fifteen on the spectrum with prominent ADHD symptoms were randomly assigned in a crossover of clinically titrated Atomoxetine and placebo for six weeks each, separated by a one-week washout. Slopes for each condition were compared by paired t-test. Twelve boys and four girls were included in the study, of which 7 had autistic syndrome, 1 had Asperger’s, and 8 had pervasive developmental syndrome. All subjects completed three weeks of treatment, including medication and placebo intervention. Out of the sixteen enrolled subjects, nine responded to Atomoxetine and recorded an improvement in their hyperactivity symptoms. The study proved that Atomoxetine appeared safe and effective for treating hyperactivity in some children with autism spectrum syndromes, and Asperger’s, being included in autism spectrum syndromes, can respond to Atomoxetine satisfactorily.
Atomoxetine is better tolerated than Methylphenidate (a first-line treatment option for ADHD) and associated with fewer chances of syndrome sleep in pediatric ADHD patients as a side effect of using the drug. It is rapidly absorbed and achieves therapeutic results without long-lasting adverse reactions or side effects.
While there was an initial loss in expected height and weight among Atomoxetine recipients, this eventually returned to normal in the longer term.
Study of height and weight in Strattera; brand name of Atomoxetine
Animal studies have proved that Atomoxetine increases extracellular levels of histamine in the prefrontal cortex involved in the pathophysiology of ADHD. Histamine plays an important role in cognitive function and memory. When stimulated by the drug, it can play an important role in improving the brain development affected by ADHD defects.
A dose of Atomoxetine once or twice daily is as effective in the short-term treatment of ADHD symptoms as the drug’s efficacy when used on a long-term basis. The drug has been equally effective in children and adolescents, including stimulant-naive patients using ADHD medications for the first time. Atomoxetine use was considered similar in effectiveness to immediate-release Methylphenidate and superior to standard therapy of other medicines and behavioral counseling. Health-related quality of life improved with the drug in both short-term and long-term use better than other treatment measures. The drug was well tolerated in all age groups with ADHD. Overall, it can be used as a comorbid Asperger therapy irrespective of the age and gender of the individual.
Key points in the use of Atomoxetine for Asperger’s
- The efficacy of the medication is similar in children and adults
- Atomoxetine is less effective than osmotically released Methylphenidate and extended-release mixed amphetamine salts.
- It is impacted by the metabolism of the CYP2D6 enzyme and shows changed pharmacodynamics in poor CYP2D6 enzyme metabolizers.
- It is less effective than drugs like extended-release amphetamine salts and osmotically released Methylphenidate
- headache, abdominal pain, decreased appetite, vomiting, somnolence, and nausea are the most common side effects of using the drug
- The use of the drug is associated with the risk of liver injury and should be avoided in patients with liver syndromes
- Treatment algorithms have determined it to be a cost-effective treatment method
- Further research is required to draw a concrete conclusion on the efficacy of Atomoxetine in Asperger syndrome
References
https://pubmed.ncbi.nlm.nih.gov/17003665/
https://www.autismspeaks.org/what-autism
