Vol. 24, Issue 2: Spring 2017
16 Years Past Diagnosis: A Look on the Outcomes of Individuals with ADHD
Attention Deficit Hyperactivity Disorder, more commonly known as ADHD, is characterized by three different qualities: inattention, hyperactivity, also known as being overactive, and impulsivity, or acting without thinking. Often thought of as a childhood disorder that goes away with age, contrasting new evidence has suggested that ADHD is a lifelong disorder. Lily Hechtman and a team of researchers at various institutions including McGill University and UC Berkeley conducted a longitudinal study that followed individuals diagnosed with ADHD in their youth in order to determine outcomes 16 years past diagnosis. These individuals were compared to a “control” group of individuals that had never been diagnosed with the disorder.
It turns out that the brain is capable of forming mental maps that are stored as unique electrical signals between cells in the hippocampus, a structure in the brain’s temporal lobe that plays a central role in memory. The cells primarily responsible for spatial memory and orientation are grid cells, place cells and head direction cells. These three cell types each play a special role in helping the brain process stimuli and navigate appropriate responses. The grid cells form a grid or graph of the surrounding environment. Each grid cell has its own firing pattern across the environment, and each cell’s firing pattern is slightly shifted relative to other cells. Place cells allow you to know when you are in a particular location, as each cell has a unique firing pattern and will only be active at certain locations. The firing of head direction cells allow for the interpretation of orientation. The different orientations of the head correspond to different firing rates of the head direction cells. These cell types work together to create a map of the environment - the grid cells form the graph paper, while the place cells indicate meaningful locations or coordinates on the graph. As you move around, the electrical activity passes from one cell to another, allowing you to know where you are in the environment based on your movements. Understanding how these cells work together to create a virtual grid across an environment may be key to researching and treating diseases related to spatial recognition, such as Alzheimer’s and epilepsy.
There has been evidence pointing to differences in functional outcomes between adults who were diagnosed with ADHD in childhood and individuals with no diagnosis. In a variety of previous studies, individuals diagnosed with ADHD during childhood were found to report substantially greater impairment regarding educational, occupational, social, and emotional criteria as adults, as compared to the adult control group with no childhood diagnoses. However, some of the previous studies used small sample sizes in which the persistence of ADHD symptoms had not been “optimally defined,” making subgrouping symptoms difficult. As symptomatology varies between individuals and diagnoses, homogeneity in the adult outcomes has not yet been displayed. This variance indicates a varying degree of functionality despite the disorder. Some adults continue to have severe symptoms, whereas others do not. This range of functionality can be attributed to “persisting” or “desisting” ADHD symptoms. In the desisting case, symptoms lessen or cease to exist. Individuals with this diagnosis were of importance in the study conducted by Hechtman and her team.
Hechtman’s study followed 579 people diagnosed with ADHD between ages 9 and 12. These individuals were assigned to four varying conditions related to their ADHD treatment plan: treatment in community care, treatment through medication, treatment through therapy, or a combined treatment of therapy and medication. Following the initial “baseline” assessment, follow-ups were done in set intervals for the next sixteen years. The study suggests that outcomes differ between the control group and those diagnosed with ADHD as children across the four domains studied: educational, occupational, social and emotional. These outcomes resulted in three overarching result patterns, the most evident one being the control group having the “best outcomes.” Those whose ADHD symptoms persisted into adulthood had the worst outcomes and the desisting ADHD individuals occupied a middle ground between the two.
Learning more about the outcomes outlined in this study can assist in intervention and treatment of both children and adults diagnosed with ADHD. This study determines three different patterns of outcomes which can be applied to future research. The “healthy control” group fared best, whereas individuals with ADHD symptoms still present had the worst outcomes in regards to education, occupation, social interactions and emotional stability. Individuals who were diagnosed with ADHD and are symptom-desisted inhabited a middle ground. The study showed that individuals who had childhood ADHD suffer more multi-faceted impairment in their daily lives, even when symptoms have desisted. This indicates that it is important to focus on intervening to improve functional outcomes early after diagnosis.