Current Research

Genetics Research

ADHD is an extraordinarily complicated and polygenic disorder. Several Genome Wide Association Studies (GWAS) and candidate gene studies have been conducted with varying success. Although there will likely not be a single gene that causes ADHD symptoms, the goal of such studies is to identify the possible genes. The genetic variation on a gene is called an allele, in which a copy is passed to child from the parents.

Among the most popular candidate genes studied are within the dopaminergic and serotonin pathways.

• DAT1 – Dopamine Transporter
• DRD4 – Dopamine Receptor 4
• DRD5 – Dopmaine Receptor 5
• 5HTT – Serotonin Transporter
• HTR1B – Serotonin 1B receptor
• CHRNA4 – Nicotinic Acetylcholine Receptor 4
• SNAP25 – Synaptosomal-associated Protein

Treatment Research

Although there are no perfect treatment options, current treatments have done a good job of minimizing side effects and helping patients with their everyday life. Research on treatment options is generally difficult for a number of reasons: completely randomized trials are difficult in medicine to maintain ethicality and long term effects are difficult to measure because there are a lot of factors to consider.

Diet Research

There are some lines of research that have explored whether or not diet may be a potential supplementary treatment option. Other research has focused on whether excessive diet in one direction will cause ADHD. However, given that human metabolism and nature of complex metabolites is extremely complex, it is unclear whether or not these dietary treatment supplements have a positive or negative effect on alleviating ADHD symptoms. In parallel, it is also not clear if certain diets will cause ADHD.

Some of the most common dietary research is on:

• Omega-3 and -6 fatty acids
• Feingold Diet
• Oligoantigenic Diet
• Sugar and Aspartame
• Iron Deficiency
• Zinc Deficiency

Pharmaceutical and Behavioral Therapy

Pharmaceuticals options vary depending on the age of the individual. Pharmaceuticals can also vary in the method of delivery and the period of time of release. Parents and doctors should decide together what is best for the child. In the US, less than 1 in 3 children are treated with both pharmaceuticals and behavior therapy. Medical treatments are known to have positive effects in the short-term, with minimal side effects, but the long term effects are generally unclear.

Among the most popular medications that are used and researched are:

• Adderall (amphetamine)
• Adderall XR (amphetamine extended release)
• Concerta (methylphenidate)
• Daytrana (methylphenidate patch)
• Dexedrine (dextroamphetamine)
• Comorbidity

Comorbidity

Many mental disorders are closely related such that individuals with ADHD are more likely to be diagnosed with other certain mental disorders such as anxiety or bipolar disorder. The conditions often mirror each other making it difficult to distinguish between the two. Current research employs mostly surveying methods of clinical data to analyze trends in comorbidity of disorders with ADHD. Surveying and self-report by the individual or parent can help aid the doctor in diagnosis of ADHD as well.

Animal Models of Research

Basic science research generally tries to use an animal model to replicate and explore some of the basic biology behind ADHD. These animal models are extremely helpful in developing new pharmaceuticals and elucidating mechanistic details behind ADHD pathways. Rodents are commonly used because of their quick reproductive cycles and high degree of mammalian correlates.

The current animal model will try to replicate three types of validity:

• Face Validity – The animal has fundamental behavioral characteristics of ADHD
• Construct Validity – the model fits with theoretical rationales for ADHD
• Predictive Validity – the model is effective in predicting novel aspects of ADHD such as treatment effects.