ADHD and ADD Definition
Attention Deficit Hyperactivity Disorder (ADHD) and Attention Deficit Disorder (ADD) are complex neurodevelopmental conditions strongly influenced by genetic factors and biological and psychosocial risk factors, possibly including physical abuse.
ADD is ADHD without symptoms of hyperactivity, people sometimes use the terms interchangeably. ADHD is the most common developmental condition in children, affecting an estimated 4-15% of school aged children (1).
According to the Centers for Disease Control and Prevention (CDC) the quantity of children that are being diagnosed with ADHD is continuing to increase. It is often carried through to adult life with studies suggesting that about 4% of adults may have ADHD (2).
The definition of ADHD rests on specific criteria (3) and relates to a primary school-aged child. ADHD can affect the emotions and behavior of people in different ways. There are three subtypes that people with ADHD generally associate with:
- Predominantly inattentive – a person may stray from their task, have difficulty remaining focused, and be disorganized not by intention or lack of understanding
- Predominantly hyperactive and/or impulsive – hyperactivity may be seen when a person constantly moves, fidgets, taps, or talks. Impulsivity is recognized in hasty actions that occur without initial thought processes.
- Combination of both inattention and hyperactivity-impulsivity
In adults, ADHD presentation differs with problems of hyperactivity less prevalent, but problems with inattention likely to persist.
Individuals with ADHD are suspected of having weakened functions in their prefrontal cortex (4). Neuropsychological and imaging studies suggest patients with ADHD have a weaker prefrontal cortex that contributes largely to their symptom presentations (4).
The prefrontal cortex is responsible for guiding behavior, thoughts, and feelings. It determines our ability to regulate attention, monitor actions, and form plans. Individuals with ADHD have been found to be consequently low in dopamine and other important neurotransmitters. Symptoms of ADHD including poor concentration, impulsivity, and hyperactivity may all originate from the weakened cortex.
Individuals with ADHD are at higher risk of physical health conditions including immune system dysfunction (5). Children are more likely to experience difficulties in getting to sleep (6), and regulating mood (7).
Treatments And Therapies
While there is no cure for ADHD, treatments are available to reduce the symptoms and improve the quality of life for ADHD patients. Some parents find making alterations to the environment, such as the removal of distractions and creating a routine is important. Lifestyle habits including yoga, meditation, and physical activity have also been supported to prevent ADHD symptoms. Some individuals choose to follow elimination diets or reduce sugar intake to improve their symptoms. Medications and lifestyle interventions may help.
First-line treatment for ADHD is a central nervous stimulant aimed at treating the three main aspects of ADHD: inattention, impulsivity, and hyperactivity. These medicines work by increasing the chemicals dopamine and norepinephrine in the brain, both of which play essential roles in thinking and attention (3). Dopamine has an important role in generating motivation, memory, and attention. Norepinephrine has been linked with arousal and helping to sustain prolonged attention.
Methylphenidate, one of the most common ADHD medications, works by blocking the reuptake of dopamine and norepinephrine and increasing their release into the space outside the neurons (8). Collectively, prescription stimulants have calming and focusing effects on individuals with ADHD.
Melatonin, a hormone produced by the brain’s pineal gland is available in the form of supplements and has proven effective for children with ADHD.
The US Food and Drug Administration (FDA) has also deemed the use of three non-stimulant medications acceptable for the treatment of ADHD.
Behavioral therapy can be an effective treatment method for ADHD. It works at replacing negative behavioral habits with positive ones. This method is most effective when used in young children and is delivered by parents using reward systems.
Cognitive behavioral therapy (CBT) can also help to address functional impairments that may be present in ADHD. A randomized controlled trial of adolescents with ADHD showed patients who received CBT showed significantly reduced symptoms of ADHD and functional impairment (9). Similar results have been seen in adult ADHD populations (10).
How Nootropics May Help ADHD and ADD
There is a growing interest of parents with children suffering from ADHD to treat with natural therapies (11). Natural therapies offer an alternative or complementary medicine that may either lessen the need for stimulant therapies or eliminate it altogether. Nootropics may be of particular interest when stimulant medications are not indicated, for example in patients with heart conditions, or abnormal blood pressure and/or heart rate. Alternatively, they may appeal to people who do not respond well to prescription medications. A study indicated that around 30% of children may experience appetite changes, difficulty sleeping, nausea, anxiety, dizziness, abdominal pain or headaches (8). Such responses highlight a niche for alternative therapies to thrive.
Animal studies indicate that the prefrontal cortex is highly sensitive to changes in the neurochemical environment. Suboptimal levels of catecholamine levels – dopamine and norepinephrine are likely to reduce the functioning of the cortex (12). The most effective treatments for ADHD are those that target the maintenance of neurotransmitters, dopamine, and norepinephrine in the brain (12). Nootropics that closely match these actions can supposedly work to increase focus, positive mood, and motivation.
Traditional herbal remedies including chamomile, kava kava, and valerian are valued due to their anxiolytic, calming effects for treating restlessness, lower concentration, and sleep difficulties in ADHD (13). Furthermore, a considerable body of evidence exists to support the idea that vitamin and mineral deficiencies are linked with hyperactivity and impulsivity in ADHD (13).
Fatty acids are one of the more well-researched nootropic supplements. Omega-3 and omega-6 fatty acids are fundamental for regular human physiological functioning. It is critical they are consumed through the diet as they cannot be synthesized by the body. Fatty acids are integral parts of the brain structure and function, particularly omega-6 arachidonic acid (AA), and omega-3 eicosapentaenoic and docosahexaenoic acids (EPA and DHA) (14). Fatty fish, such as salmon, tuna, and mackerel, are all rich sources of DHA and EPA as well as enriched eggs (15). A systematic review on the evidence of herbal and nutritional products in the treatment of ADHD found omega-3 from fish oil, DHA or flaxseed oil to be the heaviest researched nutritional medicine for ADHD treatment (14).
The association between a relative lack of omega-3 fatty acids and the development of psychiatric and neurodevelopmental issues, of which ADHD is included, has grown a considerable body of evidence (14). There is a growing body of evidence to suggest that a relative lack of omega-3 fatty acids may play a part in several neurodevelopmental and psychiatric disorders including ADHD (14). However, studies continue to show inconsistencies in results. One study to find a positive association was carried out in a group of 132 Australian children (16). The authors reported marked improvement on hyperactivity and inattention scales for those children randomly assigned to receive omega-3 supplementation (558 mg/day EPA and 174 mg/day DHA).
Data also exists to suggest that deficiencies of omega-3 fatty acids may be linked to increased hostility in adolescents (17). Long-term omega-3 deficiencies in animal studies have also resulted in reduced dopamine concentrations and its decreased binding to receptors, resulting in attention and behavior dysfunctions (18).
Omega-3 and 6 fatty acids have also proven successful in the commencement and maintenance of regular sleep patterns (19, 20). It is common for those with ADHD to experience small abnormalities in vision or hearing (21). DHA has been identified for its critical role in the effective functioning of the visual system (22).
Dosing in children is recommended to start at 500 mg and ranges up to 4000 mg/day (23). Adolescents are generally recommended doses ranging from 1000-4000mg/day (23) and some adults may require doses of 9000 mg (24).
Supplements are mostly well tolerated with the most frequently occurring side effects presenting as nausea or diarrhea (25).
Zinc is a mineral that can be obtained in the diet through food sources including meat, shellfish, legumes, nuts, and seeds. Zinc has an important role in brain function, and the prevention of brain diseases, it is a crucial cofactor for the anabolism of neurotransmitters and melatonin. Melatonin helps to regulate dopamine function (26). Zinc is also required for the effective metabolism of polyunsaturated fatty acids (PUFAs). As discussed under the segment on fatty acids, higher PUFAs concentrations are linked to reducing ADHD symptoms (27).
A study of 400 patients with ADHD compared 12 weeks of zinc sulfate supplementation (150mg/day) with a placebo. Treatment with zinc sulfate significantly improved hyperactivity, impulsivity and impaired socialization symptoms of ADHD (28). A second study comparing methylphenidate and zinc to methylphenidate and a placebo over 6 weeks demonstrated zinc sulfate significantly improved Parent and Teacher Rating Scales indicative of behavior and attention (29).
Though the exact mechanism remains unclear, it is speculated the effect may be in part be due to zinc’s effect on increasing serotonin. Zinc is an essential cofactor for the formation of pyridoxal phosphate which helps convert tryptophan to serotonin, promoting calmness (28). Improving the nutritional status of zinc in the body is likely to improve ADHD symptoms (30).
The most commonly reported adverse effects of zinc supplementation are a metallic mouth taste followed by nausea and vomiting (28). Overall, the supplement is well-tolerated in patients with ADHD.
Caffeine is one of the most widely used psychostimulants worldwide (31). It is found in many beverages including coffee, tea, and soft drinks, as well as in chocolate.
A review of 19 studies on the effectiveness of treating ADHD in children with caffeine concluded that all studies consistently found at least one benefit of caffeine (32). Increased attentiveness to tasks and lower levels of aggression were amongst some of the positive benefits. Similar results were found in adults where caffeine helped adults stay on task (33), increase reaction times, and enhance their ability to perform complex and intense tasks (34).
It has been proposed that the enhanced cognitive effects of caffeine may be due to its inhibition of the action of adenosine. Adenosine in an inhibitory neurotransmitter that depresses the nervous system (35) promoting sleep. Caffeine’s inhibitory effect on adenosine supports feelings of alertness. Caffeine also increases the activation of dopaminergic receptors (36) and causes further release of norepinephrine and epinephrine (37).
In children, the recommended dose of caffeine is around 2.5 mg/kg/day. Adverse effects have been observed between 300 – 400 mg/day (38). In adolescents, caffeine is typically administered at a dose of 200mg every 4 hourly (38).
SAMe is a compound found naturally within the body that contributes to cell division and repair. SAMe is an effective antidepressant that regulates the activity of catecholaminergic symptoms. Specifically, it stimulates the synthesis of those involved in the symptoms of ADHD, namely dopamine, norepinephrine, and serotonin (38).
A study in adults found the administration of SAMe had a positive effect on distractibility and self-control symptoms of ADHD (39), however, the effect was potentially due to the effect of SAMe on mood alone.
Benefits of SAMe are thought to be short-term (40), lasting between two and three months (38). Evidence for efficacy remains limited and its effectiveness as a nutritional supplement for ADHD is mostly based on rational rather than clinical studies.
Inositol or vitamin B8 is an isomer of glucose. Inositol is thought to increase levels of serotonin in the brain and may be involved with the actions of dopamine and norepinephrine. Increased serotonin promotes calmness.
Some studies have found the use of Inositol to worsen the symptoms of ADHD (42) which others have found it is linked to improved symptoms in children (43).
Inositol is typically dosed between 12 and 18g daily (41). In quantities up to 20g per day, it is generally well-tolerated (44).
Pycnogenol is the collective name for procyanidins that originate from the bark of pine trees Pinus maritima. The use of Pycnogenol for its antioxidant and possible anti-inflammatory effects has existed in Europe for decades, mostly in the treatment of hyperactivity. It is thought to impact the release of dopamine and norepinephrine
In a singular case study, pycnogenol supplements were given to individuals with ADHD for four weeks. Large declines were seen in symptoms of hyperactivity and impulsivity (45).
A later investigation on 61 children and adolescents with ADHD found that taking 1 mg/kg body weight of pine bark extract for a month also had beneficial effects on ADHD. Hyperactivity was reduced, and attention and visual-motor coordination were increased, with results more profound in males (46).
Pycnogenol is most often dosed at a level of 1 mg to every kilogram of body weight in children. Adult doses range between 25–200 mg/day. Pycnogenol is mostly well tolerated (25).
Ningdong granule is a preparation used in traditional Chinese medicine for the treatment of diseases in China for centuries.
A double-blind trial was conducted on 72 children with ADHD who were randomized to receive either Ningdong granule (5 mg/kg/day) or methylphenidate, one of the most common and effective drugs for ADHD symptom improvements. The authors reported that Ningdong granule improved symptoms of ADHD with fewer side effects than methylphenidate. It was recommended as a safe and effective ADHD treatment for children in the short-term, with further research required for long term efficacy (47).
Evidence on the link between iron and ADHD is a little less convincing. The positive effects reported thus far are thought to result from addressing iron deficiencies (48). Non-anaemic ADHD children with existing low ferritin levels were randomized to receive either oral iron (ferrous sulfate 80 mg/day), or a placebo (49). Iron supplementation significantly improved symptoms of ADHD when compared to the placebo. Supplementation was well tolerated and the effectiveness of treatment was regarded by authors to be comparable to stimulants. However, there appear to be limited benefits of additional iron for individuals with normal ferritin levels.
Acetyl-L carnitine is a metabolite that is essential for the production of energy, and the synthesis of fatty acids.
A study on 112 children with ADHD randomized participants to receive either a placebo, or 1000 mg/day – 3000 mg/day of acetyl-L carnitine (depending on the weight of the child). The authors reported that there was little effect of treatment on the overall study population, however, when the population was broken down into its subtypes of ADHD, trends appeared. Those with the inattentive type of ADHD experienced greater benefits with acetyl-L carnitine supplementation over the placebo (50).
When it comes to nootropics for the relief of ADHD symptoms, there are many natural therapies with promising evidence. Once again, the role of neurotransmitters ranks in as a highly important consideration for the treatment of ADHD and ADD. Nootropics that promote increased concentrations of dopamine and norepinephrine appear to provide suitable complementary or alternative therapies to stimulant medications.
Nootropics, also recognized throughout the literature as ‘smart drugs’, ‘cognitive enhancers’, and ‘neuroenhancers’, have a place in the treatment of ADHD symptoms. Though many nootropics are advertised for their protective effect on ADHD, supporting evidence is often low quality or may be based on rationale alone. The nootropics discussed in this article show promising therapeutic potential for their use to reduce ADHD symptoms.
Always discuss with your pharmacist or doctor before taking nootropics and ADHD medication at the same time to prevent negative drug-drug interactions.