| Researchers from Norway report that they have | | | | spontaneously hypertensive rat (SHR) displayed all the |
| found a rat model for the Predominantly Inattentive | | | | main symptoms of ADHD/HI (Hyperactive/Impulsive |
| subtype of ADHD (ADHD-PI). This type of ADHD is | | | | sub-type) and that this rat also had the predicted |
| characterized by Inattention without hyperactivity or | | | | disturbances in the brain's nervous system when they |
| impulsiveness. The researcher reported in | | | | were compared to a rat with no ADHD symptoms. |
| Neuropharmacology (2009 Dec;57), that "The WKY | | | | The discovery of an animal model for ADHD-PI is an |
| rat obtained from Charles River Germany provides a | | | | exiting finding as finally ADHD-PI can be more |
| promising model for the predominantly inattentive | | | | thoroughly studied. Treatment studies almost always |
| subtype of ADHD." | | | | use animals for testing first. If the treatment shows |
| Inattentive ADHD is less common than Hyperactive | | | | promise in the animal then the study moves on to |
| Impulsive ADHD (ADHD-HI). It affects a great many | | | | human testing. Without an animal model for ADHD-PI, |
| people but it gets less attention than ADHD-HI | | | | promising treatment possibilities cannot be explored. |
| because the symptoms are less obvious and less | | | | There is some thought though that it is not only genes |
| disruptive to the every day functioning of classrooms | | | | that are important but that both the environment and |
| and family life. The inattentive type of ADHD is | | | | genes play a role in all types of ADHD. They have |
| disabling in a different way than the Hyperactive | | | | used rats to look at the influence of environment as |
| Impulsive subtype. The discovery of this animal model | | | | well as the influence of genes. Another study of rats |
| will help researchers learn more about this subtype of | | | | was done in South Africa using SHR rats that were |
| ADHD. | | | | mothered by rats without ADHD/HI or ADHD/C |
| We know that ADHD is genetic, it runs in families and | | | | (Combined sub-type). This study found that mothering |
| is 80% inheritable. An animal with similar genes will | | | | had no impact on the ADHD behavior of rats with |
| respond to treatment similarly to a human with the | | | | ADHD/HI or the behavior of rats with ADHD/C. |
| same gene problem. The researchers will study the | | | | Studies such as this one will be performed using the |
| gene structure of the WKY rat to gain a better | | | | WKY Rat and will give us further insight into the roll the |
| understanding of the genetics involved in ADHD-PI. | | | | environment plays in people with Inattentive ADHD. |
| Several years ago researcher found that the | | | | |