Understanding ADHD Symptoms
Danielle Daniel
Doctorate Research Paper
Attention Deficit/Hyperactivity Disorder is one of the most commonly diagnosed neurodevelopmental disorders in children today (Vargo 2015). “The essential feature of attention-deficit / hyperactivity disorder (ADHD) is a persistent pattern of inattention and/or hyperactivity-impulsivity that interferes with functioning or development” (APA 2013, pg. 61). Since ADHD is characterized primarily by inattention, and/or hyperactivity/impulsivity, these behaviors can lead to impaired cognition and difficulty in functioning (Volkow et al. 2011). Because there are many crossover symptoms in ADHD with other mental health diagnosis, professionals need to take precaution to not misdiagnose ADHD for another presenting concern such as a learning disability, stress, anxiety, oppositional defiant disorder, intermittent explosive disorder, reactive attachment disorder, addictions, bipolar disorder, depression, other neurodevelopmental disorders such as an intellectual disability, or even a medication-induced symptom of ADHD (APA 2013). The inability to sustain focus and attention may not be due to the neural pathways that are indicative of ADHD which is why it is important to understand this diagnosis, what contributes to the development of ADHD, how it presents in the brain, how it presents in an individual and the various intervention options to improve symptoms.
ADHD is more frequently diagnosed in males than in females and more prevalently seen in the caucasian populations in the United States (APA 2013). With the central features of ADHD being inattention, hyperactivity, or impulsivity), persons with this diagnosis have difficulty sustaining attention and this generally first manifests in young school age children resulting in an inability to stay on task, focus or stay organized in accordance to the developmentally appropriate standards of that child's age (APA 2013). Hyperactivity is a subfeature that can accompany this diagnosis and refers to excessive motor activity such as restlessness, that manifest in various ways like fidgeting, tapping, getting out of one's seat when not appropriate, or over talkative (APA 2013). Lastly, impulsivity is a feature of ADHD such as hasty actions without prior planning or forethought potentially having a safety risk such as harm to oneself or harm to another (APA 2013). Something important to note as a key factor in this diagnosis is that these behaviors are present not only in the school setting for example, but also in other environments such as home or in the community (APA 2013).
Being that the main features of ADHD are inattention and/or hyperactivity and impulsivity, it is important to recognize that these features can crossover and present in other mental health diagnosis however, the primary cause of these symptoms may not have the same etiology in other mental health diagnosis as it does in ADHD. For example, children with a specific learning disability may also display inattention because of frustration with a limited ability in their learning comprehension rather than due to the neuropathology found in ADHD (APA 2013). Plus when these children with a specific learning disability are not in a learning environment, these same symptoms of inattention would not persist, therefore helping to further distinguish the diagnosis. Children on the autism spectrum may also display inattention or impulsivity due to difficulty with stimulation and social environments (APA 2013).
In looking at the psychopathology of ADHD, there are several theories and various research studies finding multiple pathways and communication systems implicated. The frontal lobe in the brain is the primary cognitive control center carrying out our major executive functions such as impulse control, organization, planning, mental flexibility, self-monitoring, maintaining attention, implementing goal-oriented behavior, strategic planning and many more important tasks (Vargo 2015), (Carter et al. 2009), (Aman et al. 1998). The pre-frontal cortex uses a short-term memory called working memory to process and collect information, allowing us to implement goal-oriented behavior and strategic planning. The distractibility, forgetfulness, impulsivity, hyperactivity and poor planning skills seen in ADHD have suggested a correlation in the miscommunication of these brain pathways including impairment in the dopaminergic transmissions in these brain functions (Carlson 2013).
When examining structural abnormalities, there is evidence that the right parietal
lobe along with the frontal lobe regions of the brain are implicated in ADHD. As already mentioned, the frontal lobes of the brain are thought to play a major role in performing executive functions such as controlling impulses, inhibiting responses, and strategizing. The parietal lobes are responsible for sensory input from sensory areas and visual regions of the brain. MRI studies have confirmed these structural differences and though these structural differences exist, it could be due to other neurological deficits that affect both the frontal and parietal functioning (Aman et al. 1998). The nucleus accumbens is heavily involved in reward processing and has been found in fMRI studies in ADHD to have atypical activation and signaling in this region during reward tasks (Psychology & Psychiatry Journal 2013). One research article studied the neuropathology in ADHD and found that there is a dysfunction in the reward and motivation systems of the midbrain. The dopamine pathways in the mesoaccumbens of the brain where the rewards system projects into the nucleus accumbens, shows via positron emission tomography (PET) that there is lower dopamine D2/D3 receptors available in the nucleus accumbens and midbrain regions in persons diagnosed with ADHD compared to controls (Volkow et. al. 2011). The nucleus accumbens and dopamine pathways are the key brain regions for reward and therefore motivation. This study showed that compared with controls, those with ADHD have a decreased response in the brain for rewards therefore the motivation to stay on tasks is lower. This study also showed a positive correlation between these dopamine receptors D2/D3 in the midbrain and positive emotionality (Volkow et. al. 2011). The research suggests that higher rewards be implemented as an intervention to improve motivation and therefore inattention symptoms. They also suggest that impaired motivation may be an underlying contributor to the inattention in ADHD and propose that a new symptom be included in the diagnosis of ADHD of motivation deficit (Volkow et. al. 2011).
ADHD symptoms are associated with multiple neurotransmitter pathways (Psychology & Psychiatry Journal 2013) such as the dopaminergic and noradrenergic activating systems in the forebrain (Kolb & Whishaw 2014). Low dopaminergic activity has been commonly seen in ADHD as previously discussed in the midbrain, however, dopaminergic activity in the hippocampus which is essential for both learning and memory is also reported low. In a study with animal model ADHD, researchers found low dopamine receptor density in the hippocampus (Medin 2013). Another article reported that low dopaminergic activity is found associated predominantly in the hyperactive-impulse behaviors of ADHD, and the inattentive type has been more dominantly associated with changes in norepinephrine. Serotonin levels have also been found implicated in ADHD and serotonin is associated with impulse control and aggression whereas dopamine and norepinephrine neurotransmitters are associated with reward processing (Gromisch 2010).
Dopamine transporter genes and dopamine D4 and D5 receptor genes have been strongly linked to the inattentive symptoms and the hyperactive-impulse symptoms of ADHD per another article (Gizer et. al. 2012). Another studied confirmed the involvement of dopamine D4 and found that D4 receptors play a key role in modulating striatal glutamate release and due to the abnormal levels of D4, it causes a weaker control of glutamate neurotransmission and could be the main mechanism behind the pathology of ADHD (Gonzalez et. al. 2012). One more article noted an imbalance in the GABAergic transmission as well as the dopaminergic in ADHD (Psychology & Psychiatry Journal 2013).
In summary of the neuropathology in ADHD, much has been discovered in regards to the implications of the rewards system in the brain and dopaminergic transmission as well research is seeing implication in communication pathways of the neurotransmitters norepinephrine, serotonin, GABA and Glutamate. However, there is still more to be researched before any singular pathology can be determined conclusive for identifying ADHD.
The most common psychopharmacological treatment is through the use of methylphenidate drugs such as Ritalin. Long term use of this drug is not yet fully researched, however short term usage has been shown to help improve attention and hyperactivity via the dopaminergic pathways as Ritalin blocks dopamine reuptake, allowing one to experience the effects of dopamine longer in the brain. Ritalin use however is raising concerns of addictive behavior in teens and may increase the risk of heart attack, high blood pressure, and produce psychotic symptoms in some (Comer 2010).
There are other various factors to consider when looking at ADHD holistically. Stress is one of those and should not be underestimated as it causes neurochemical changes in the brain and has been found to cause brain damage in developing brains. Glucocorticoids, which are steroid hormones, including cortisol, a hormone that is released in the response to stress, destroy neurons. This has been found in turn to cause hippocampal deterioration, neuronal communication disruption, and it even has been found to alter the development of the amygdala. The hippocampal formation plays a primary role in memory and learning and when degeneration of the brain structure happens, memory loss becomes the side effect. (Carlson 2013). Stress can interrupt neuronal communication and especially negatively affect a child’s developing brain, being extremely detrimental to their brain function and development. Providing a low stress, loving environment for children is essential to their healthy brain development and function.
Elimination diets have been researched as well and many have found benefits from following these diets. Because behavioral reactions have been seen with certain food consumption, elimination diets can be a useful way to improve certain behaviors. The main elimination diet that has been studied in regards to ADHD is the gluten-free and/or casein-free (GFCF) diet. Because digestion of gluten and casein produces opioid peptides to permeate the bloodstream that then travel to the brain and bind to opioid receptors in the brain, in a child with ADHD who is experiencing a disrupt already in abnormal neurotransmission, the extra opioid receptors can exacerbate behavioral symptoms in these children (Verena et. al. 2017). Other popular elimination diets are cutting out salicylates such as from aspirin, food additives such as preservatives, artificial flavors and coloring. Salicylates are said to increase hyperactive behavior in some and artificial additives are thought to have a slight allergic reaction in the body therefore increasing ADHD symptoms due to the activation of the immunoglobulin (Ig) antibodies causing a myriad of defenses to ignite in the immune system in the gut (Verena et. al. 2017).
Other studies have found that the gut-brain connection with intestinal microbiota is linked to ADHD. Gut flora, or good bacteria in the intestines, is involved in various processes for the body including that of energy utilization, digestion and absorption of nutrients. The microbiome plays a critical role in the immune system and ultimately the health of the body and has been found to influence activity in the frontal lobe such as organizing, planning, and task completion. Gut dysbiosis, or overgrowth of bad bacteria in the intestines, has been linked to several mental health dysfunctions including inflammation, cancer, obesity neurological disorders and several other human diseases (Verena et. al. 2017). The microbiome has been shown to directly impact mood, stress response, and several other aspects of behavior due to its direct gut-brain pathways of the central nervous system. This bidirectional connection is thought to start with the intestinal system connection to the Vagus nerve which thens mediates signals to the brain depending on the nature of the stimuli. Next this stimuli interacts with the immune system causing neuroactive metabolites to occur which alter gene expression and interact with nerve cells by stimulation of the sympathetic nervous system. Lastly in this chain of command is the effects from the microbiome on neurotransmission such as serotonin, GABA, dopamine, norepinephrine and acetylcholine (Verena et. al. 2017), (Cenit et. al. 2017). Various studies have investigated the association of probiotics and behavior showing positive results. Psychobiotics, or probiotics with a psychological benefit, can help with immune system functioning, cortisol processing from stress, and influence neurotransmission (Cenit et. al. 2017). Particular bacterial strains have been studied to mediate behavioral effects via the vagus nerve and reduce stress hormones such as norepinephrine and cortisol. Lactobacillus and Bifidobacterium have been shown to produce GABA; Escherichia, Bacillus and Saccharomyces can aide in norepinephrine production; Candida, Streptococcus, escherichia and enterococcus have a direct involvement with supporting serotonin; Bacillus produces dopamine, and Lactobacillus produces acetylcholine (Cenit et. al. 2017). These neurotransmitters, such as the dopamine and norepinephrine pathways, project to the prefrontal cortex and striatum and have been seen to modulate cognitions and behaviors involved in the reward perception which play a crucial role in ADHD (Cenit et. al. 2017). What is interesting to note is that many of the environmental factors associated with ADHD, are also associated with risk to the gut microbiome leading to gut dysbiosis so there is strong evidence of this gut-brain connection and the health benefits of psychobiotics for symptoms of ADHD (Cenit et. al. 2017).
In looking at other alternative interventions to support the symptology of ADHD, aromatic compounds are showing promising results. In this paper, I will focus just on the symptoms of inattention in regards to aromatic compounds and review the research findings that show improved attention and alertness. Aromatic compounds are lipophilic volatile chemical constituents that exist in the seeds, stems, peel, bark, roots, resin etc. of various plants. These plants are studied in science to better understand their chemical constituents and beneficial actions they produce in nature and in humans. These aromatic compounds, also called essential oils, are absorbed into the body via three main pathways; transdermally through the skin, inhaled through olfactory neural pathways, or ingested and delivered through the digestive system (Perry & Perry 2006). Research on essential oils has been done for many years, however the field is still in its pioneering phase to understand these complex compounds in nature. Most studies at this point are done on healthy individuals or mental health induced mouse models testing measures that are used to determine psychopharmacology results as well. Performing research on diagnosed patients is in its infancy and is gaining popularity as aromatics continue to show promising results.
Many essential oils have positive effects on increasing attention and alertness, especially that of the plants peppermint and ylang ylang. A study on peppermint essential oil found that when subjects were exposed to a demanding stressful workload, they were able to sustain better visual attention in this environment through inhalation of peppermint oil compared to controls (Warm et. al. 1991). Another study on peppermint oil found that subjects were able to sustain alertness compared to controls and showed less sleepiness than controls in a darkened room (Norrish & Dwyer 2005). One study found that peppermint and cinnamon essential oils were able to increase alertness and wakefulness compared to controls with no-odor in a driving simulation test (Raudenbush et. al. 2009). A study done with 144 healthy volunteers assigned randomly to either peppermint essential oil, ylang ylang, or no odor as the control group were tested on mood and cognitions after inhalation of the odors and the data found a significant increase in alertness from peppermint oil and significant increase in calmness from ylang ylang (Moss et. al. 2009). A study on ylang ylang essential oil, which comes from the ylang ylang flower, showed that compared to controls, ylang ylang oil produced a harmonization effect rather than relaxation or sedation as well as increased attentiveness and alertness (Hongratanaworakit & Buchbauer 2004). These various studies show positive results on attention and alertness through the use of peppermint and ylang ylang essential oil and would be a safe way to naturally influence the mental state.
Rosemary essential oil has also received much attention in the field of aromatic science due to its various benefits for the body. Research has also shown that rosemary can have a positive effect on alertness and attention. One study with 40 healthy adults, administered rosemary essential oil to participants given various math computations to complete. Those subjects who were given the rosemary oil showed a decrease in alpha and beta power activity suggesting an increase in alertness. The subjects with the rosemary oil also reported higher scores of feeling relaxed, alert, and completed their math computations faster than controls (Diego et. al. 1998). Another study on rosemary essential oil took 144 healthy participants and randomly assigned them to one of three groups of either rosemary, lavender or no odor and had them complete the Cognitive Drug Research (CDR) computerized test. Rosemary essential oil had a significant increase on the subjects quality of memory and alertness in test performance compared to both lavender and no odor however, results showed that the group with no odor was significantly less content than the groups exposed to both essential oils (Moss et. al. 2003). Rosemary therefore has been seen to increase alertness and memory in academic performance and could be a possible benefit to the symptoms of inattention.Studies on Sage oil also show positive findings for increased attention. One research group took the extract of Salvia Officinalis in a randomised, placebo-controlled, double blind, balanced, five-period crossover study with 20 healthy volunteers and administered the Cognitive Drug Research (CDR) computerised assessment following the ingestion of the sage oil or a placebo. Results showed that compared with the placebo, there was a significant enhancement of secondary memory during all the test performance times from the Sage extract group. Sage also had a significant increase to accuracy of attention compared to the controls (Scholey et. al. 2008). Another double-blind, placebo-controlled, balanced crossover study on the extracts of Salvia lavandulaefolia, another species of sage oil, had 36 participants take capsules of sage orally prior to a computerised memory and attention task assessment and the administration of the Cognitive Demand Battery test. Results showed that with oral consumption of sage, it lead to improved performance of secondary memory and attention tasks compared to controls. Sage notably reduced mental fatigue and increased alertness in this study including improved cognitive performance and mood (Kennedy et. al. 2011). Sage therefore has been seen to not only improve alertness and attention but also memory with reduced mental fatigue. This could be a helpful natural compound to use in a school setting or prior to any mental task one needs to sustain focus.
Jasmine essential oil is highly prized for its beautifying benefits on the skin, however it also was found to benefit the mind in a study done on 40 healthy volunteers. Subjects were given either jasmine oil to apply topically over the abdomen area or an odorless placebo. The study found that the jasmine oil produced an increase in autonomic arousal and participants rated themselves as feeling more alert and vigorous compared to controls (Hongratanaworakit 2010). Another study on sandalwood essential oil elicited higher ratings of attentiveness following the inhalation of the oil (Heuberger et al. 2006). These findings suggest that jasmine and sandalwood essential oils can support the brain in remaining more alert and attentive after application.
Lastly, one small study was done with 2 ADHD diagnosed patients using chamomile essential oil. After oral administration of Matricaria chamomilla 3 times a day for 4 weeks, participants were evaluated on the ADHD Rating Scale that is used to measure the symptoms of inattention, hyperactivity/impulsivity to diagnose ADHD. The patients were free of all psychotropic medication for at least 1 week and scores on the ADHD Rating Scale were compared prior to the chamomile and after. The results showed that the inattention score dropped with chamomile use as well as the hyperactive/impulsive score by more than 50-60% whereas the placebo groups post test showed similar scores to their pre-test. This study concluded that chamomile in patients with ADHD could be an effective additive to treatment to improve attention and behavior (Niederhofer 2009).
There are various other studies on essential oils and neurotransmitter involvement including dopamine, serotonin and norepinephrine, which are the primary neurotransmitters involved in ADHD as well as there are numerous studies on the behavior calming actions of essential oils that could benefit ADHD. The study of aromatics and psychology is an exciting field and holds a lot of potential for the brain.
The studies on ADHD continue to expand and shed more light on the primary causes and concerns as well as the most effective interventions. When looking at a holistic approach, there are many solutions available to families that can improve one's ability to sustain attention and thrive successfully in their environment.
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