What is ADHD?
Attention deficit/hyperactivity disorder (ADHD) is a behavioral condition characterized by inattention, impulsivity, and hyperactivity. Most people experience these behaviors from time to time, but in ADHD, they are more severe, happen more often, and interfere with a person’s ability to function socially, at school, or in the workplace.[1] ADHD is divided into three subtypes by predominant symptomatology: Inattentive (ADHD-I), Hyperactive-Impulsive (ADHD-HI), and Combined (ADHD-C). Symptom clusters can change as individuals mature and develop.[2]
What are the main signs and symptoms of ADHD?
People with ADHD can show signs of inattention, hyperactivity, impulsivity, or both.[3] This can manifest as difficulty paying attention to details, getting sidetracked from schoolwork, troubles with organization, and being easily distracted. Other behaviors include fidgeting or squirming, inability to remain seated when expected, inappropriate running or climbing, and talking excessively. ADHD in adults is often internalized and may present as restlessness, scattered thoughts, and poor time management.[4]
How is ADHD diagnosed?
In children, at least six of the symptoms mentioned need to be present to qualify for a diagnosis; in adults, only five. In both cases, these symptoms need to be present for more than 6 months and interfere with academic, occupational, or social functioning.[5]
What are some of the main medical treatments for ADHD?
Except in children under age 5, medications are considered the first-line treatment for ADHD.[6][7] Short- and long-acting forms of amphetamines and methylphenidate — stimulants that increase levels of dopamine and norepinephrine in the brain — are most commonly prescribed and considered highly effective for treating ADHD.[8][9]
Other nonstimulant medications used for ADHD include atomoxetine,[10] bupropion,[11] and tricyclic antidepressants.[12]There is some preliminary research suggesting that modafinil may improve ADHD, but much more research is needed.[13]
Have any supplements been studied for ADHD?
Fish oil contains the omega-3 fatty acids DHA (docosahexaenoic acid) and EPA (eicosapentaenoic acid), which have well-supported anti-inflammatory properties and can regulate neurotransmitter and immune function, and as a result, may improve ADHD.[14]
Ginkgo biloba increases blood flow in the human brain and the signaling of serotonin and norepinephrine in rats, which may contribute to its mild, positive effect on ADHD.[15][16]
Both L-carnitine and acetyl-L-carnitine are present in brain cells and play an important role in energy production — it’s possible that by increasing mitochondrial activity in neurons and promoting dopamine signaling, carnitine could improve symptoms of ADHD.[17]
Supplementing with phosphatidylserine (a phosphorus-containing lipid) seems to positively affect ADHD,[18] which is likely due to its important role in adjusting receptor, enzyme, and ion channel activity, and consequently, affecting the signaling of most neurotransmitters in the brain.
How could diet affect ADHD?
A number of dietary interventions for ADHD have been studied, including the elimination of artificial food colorings, diets high in polyunsaturated fatty acids (PUFAs), and the few-foods diet (a type of elimination diet that gradually reintroduces foods based on how a person’s symptoms change).[19] High-PUFA diets aren’t likely to improve ADHD symptoms, but the few-foods diet is promising. More research on dietary artificial food coloring intake is necessary before it can be recommended for treating ADHD.
Are there any other treatments for ADHD?
Behavioral strategies can be used to manage ADHD symptoms, and include:[20]
- Keeping a consistent schedule
- Minimizing external distractions
- Setting small, reachable goals
- Identifying unintentional reinforcement of negative behaviors
- Using charts and checklists
- Limiting choices
- Using calm discipline in children (e.g., time out)
Psychotherapy and cognitive behavioral therapy can be helpful for children and adults with ADHD, although it’s not recommended as a substitute for medication.[21]
What causes ADHD?
The exact etiology of ADHD is unknown but is thought to involve structural and neurochemical alterations in brain regions responsible for executive function, memory, and information processing.[22][23] Norepinephrine and dopamine signaling play a major role in the function of these brain regions, and individuals with ADHD tend to have lower levels of both of these neurotransmitters than individuals without ADHD.[22]
ADHD has a strong genetic component. The risk of ADHD is increased by 2–8 times in individuals who have a parent or sibling with ADHD, and pooled twin studies suggest that the heritability of ADHD is nearly 80%.[24]
Examine Database: Attention Deficit Hyperactivity Disorder (ADHD)
Research FeedRead all studies
Frequently asked questions
Attention deficit/hyperactivity disorder (ADHD) is a behavioral condition characterized by inattention, impulsivity, and hyperactivity. Most people experience these behaviors from time to time, but in ADHD, they are more severe, happen more often, and interfere with a person’s ability to function socially, at school, or in the workplace.[1] ADHD is divided into three subtypes by predominant symptomatology: Inattentive (ADHD-I), Hyperactive-Impulsive (ADHD-HI), and Combined (ADHD-C). Symptom clusters can change as individuals mature and develop.[2]
ADHD involves inattention, impulsivity, and hyperactivity, whereas autism is characterized by stereotyped behavior and impaired social and communication skills. On the surface, there seems to be little in common between these two disorders at first glance.
One feature they do have in common is that they rarely present alone. In the words of two researchers:[25] “It is the exception, not the rule, to encounter cases with ‘pure’ ADHD”, and the same also seems to hold true for ASD. It’s not uncommon for attention issues and full-blown ADHD to be found[26] in children with ASD. The reason aspects of these conditions can overlap may come down to where they occur in the brain. Both involve some of the same regions of the brain, in what is known as the frontostriatal system. Disorders that arise from this region are thus known as frontostriatal disorders,[27] which include ADHD and ASD. Recent neuropsychological evidence[28] suggests that ADHD and ASD share some similar brain circuits and both involve problems with managing cognitive processes and emotions, self-control, and executing complex tasks (collectively known as executive dysfunction), implying that both disorders may have some underlying similarities.
People with ADHD can show signs of inattention, hyperactivity, impulsivity, or both.[3] This can manifest as difficulty paying attention to details, getting sidetracked from schoolwork, troubles with organization, and being easily distracted. Other behaviors include fidgeting or squirming, inability to remain seated when expected, inappropriate running or climbing, and talking excessively. ADHD in adults is often internalized and may present as restlessness, scattered thoughts, and poor time management.[4]
In children, at least six of the symptoms mentioned need to be present to qualify for a diagnosis; in adults, only five. In both cases, these symptoms need to be present for more than 6 months and interfere with academic, occupational, or social functioning.[5]
While symptoms of ADHD often begin early in childhood, adults can continue to have symptoms of ADHD that interfere with their daily functioning, and some adults with ADHD may not even know they have the condition. It is estimated that the prevalence of persistent adult ADHD (with the onset in childhood) is around 2.5% and the prevalence of symptomatic adult ADHD is around 6.7% globally.[29]
The symptoms of ADHD may present differently in adults compared to children. For example, hyperactivity in children may manifest as running, jumping, or making noise while in adults, hyperactivity may take the form of restlessness or scattered thoughts.[4] There are other ADHD symptoms that are more specific to adults including:[30][31]
- Difficulty prioritizing tasks
- Difficulty planning
- Poor time management (e.g., missing or double-booking appointments)
- Difficulty regulating emotions
Except in children under age 5, medications are considered the first-line treatment for ADHD.[6][7] Short- and long-acting forms of amphetamines and methylphenidate — stimulants that increase levels of dopamine and norepinephrine in the brain — are most commonly prescribed and considered highly effective for treating ADHD.[8][9]
Other nonstimulant medications used for ADHD include atomoxetine,[10] bupropion,[11] and tricyclic antidepressants.[12]There is some preliminary research suggesting that modafinil may improve ADHD, but much more research is needed.[13]
Fish oil contains the omega-3 fatty acids DHA (docosahexaenoic acid) and EPA (eicosapentaenoic acid), which have well-supported anti-inflammatory properties and can regulate neurotransmitter and immune function, and as a result, may improve ADHD.[14]
Ginkgo biloba increases blood flow in the human brain and the signaling of serotonin and norepinephrine in rats, which may contribute to its mild, positive effect on ADHD.[15][16]
Both L-carnitine and acetyl-L-carnitine are present in brain cells and play an important role in energy production — it’s possible that by increasing mitochondrial activity in neurons and promoting dopamine signaling, carnitine could improve symptoms of ADHD.[17]
Supplementing with phosphatidylserine (a phosphorus-containing lipid) seems to positively affect ADHD,[18] which is likely due to its important role in adjusting receptor, enzyme, and ion channel activity, and consequently, affecting the signaling of most neurotransmitters in the brain.
A number of dietary interventions for ADHD have been studied, including the elimination of artificial food colorings, diets high in polyunsaturated fatty acids (PUFAs), and the few-foods diet (a type of elimination diet that gradually reintroduces foods based on how a person’s symptoms change).[19] High-PUFA diets aren’t likely to improve ADHD symptoms, but the few-foods diet is promising. More research on dietary artificial food coloring intake is necessary before it can be recommended for treating ADHD.
Behavioral strategies can be used to manage ADHD symptoms, and include:[20]
- Keeping a consistent schedule
- Minimizing external distractions
- Setting small, reachable goals
- Identifying unintentional reinforcement of negative behaviors
- Using charts and checklists
- Limiting choices
- Using calm discipline in children (e.g., time out)
Psychotherapy and cognitive behavioral therapy can be helpful for children and adults with ADHD, although it’s not recommended as a substitute for medication.[21]
Exercise is one of the most-recommended nonpharmacological treatments for ADHD in adults and children. Some of the benefits of exercise for ADHD are theoretical, and include promoting dopamine release in the brain, improving executive functions, increasing levels of brain-derived neurotrophic factor (BDNF), and regulating behavior and attention.[33] Studies have shown that exercise can increase attention in children with ADHD,[34] and improve symptoms of ADHD and executive function in ADHD patients.[35]
Cannabis is a common form of self-medication among adults with ADHD, but there is very little clinical research to support claims of either harm or benefit from regular cannabis use. Some data suggest that adults with ADHD may be 2-3 times more likely to use cannabis than adults without ADHD and may also be at an increased risk for cannabis use disorder.
Cannabis may improve symptoms of inattention in ADHD. However, cannabis use is also associated with neurocognitive deficits and reduced memory and executive functions in adults with and without ADHD. Thus, while many adults with ADHD advocate for cannabis’s therapeutic effects, clinical trials are needed to study the direct effects of cannabis use on ADHD symptoms.[36]
The exact etiology of ADHD is unknown but is thought to involve structural and neurochemical alterations in brain regions responsible for executive function, memory, and information processing.[22][23] Norepinephrine and dopamine signaling play a major role in the function of these brain regions, and individuals with ADHD tend to have lower levels of both of these neurotransmitters than individuals without ADHD.[22]
ADHD has a strong genetic component. The risk of ADHD is increased by 2–8 times in individuals who have a parent or sibling with ADHD, and pooled twin studies suggest that the heritability of ADHD is nearly 80%.[24]
References
Examine Database References
- ADHD Symptoms - Torrioli MG, Vernacotola S, Peruzzi L, Tabolacci E, Mila M, Militerni R, Musumeci S, Ramos FJ, Frontera M, Sorge G, Marzullo E, Romeo G, Vallee L, Veneselli E, Cocchi E, Garbarino E, Moscato U, Chiurazzi P, D'Iddio S, Calvani M, Neri GA double-blind, parallel, multicenter comparison of L-acetylcarnitine with placebo on the attention deficit hyperactivity disorder in fragile X syndrome boysAm J Med Genet A.(2008 Apr 1)
- ADHD Symptoms - L Eugene Arnold, Antonino Amato, Hernan Bozzolo, Jill Hollway, Amy Cook, Yaser Ramadan, Lindsay Crowl, Dan Zhang, Susan Thompson, Giussepe Testa, Vernon Kliewer, Timothy Wigal, Keith McBurnett, Michael ManosAcetyl-L-carnitine (ALC) in attention-deficit/hyperactivity disorder: a multi-site, placebo-controlled pilot trialJ Child Adolesc Psychopharmacol.(2007 Dec)
- ADHD Symptoms - Van Oudheusden LJ, Scholte HREfficacy of carnitine in the treatment of children with attention-deficit hyperactivity disorderProstaglandins Leukot Essent Fatty Acids.(2002 Jul)
- ADHD Symptoms - Seyed-Hesameddin Abbasi, Shahram Heidari, Mohammad-Reza Mohammadi, Mina Tabrizi, Ali Ghaleiha, Shahin AkhondzadehAcetyl-L-carnitine as an adjunctive therapy in the treatment of attention-deficit/hyperactivity disorder in children and adolescents: a placebo-controlled trialChild Psychiatry Hum Dev.(2011 Jun)
- ADHD Symptoms - Jane Pei-Chen Chang, Kuan-Pin Su, Valeria Mondelli, Senthil Kumaran Satyanarayanan, Hui-Ting Yang, Yi-Ju Chiang, Hui-Ting Chen, Carmine M ParianteHigh-dose eicosapentaenoic acid (EPA) improves attention and vigilance in children and adolescents with attention deficit hyperactivity disorder (ADHD) and low endogenous EPA levelsTransl Psychiatry.(2019 Nov 20)
- ADHD Symptoms - Richardson AJ, Puri BKA randomized double-blind, placebo-controlled study of the effects of supplementation with highly unsaturated fatty acids on ADHD-related symptoms in children with specific learning difficultiesProg Neuropsychopharmacol Biol Psychiatry.(2002 Feb)
- ADHD Symptoms - Bos DJ, Oranje B, Veerhoek ES, Van Diepen RM, Weusten JM, Demmelmair H, Koletzko B, de Sain-van der Velden MG, Eilander A, Hoeksma M, Durston SReduced Symptoms of Inattention after Dietary Omega-3 Fatty Acid Supplementation in Boys with and without Attention Deficit/Hyperactivity DisorderNeuropsychopharmacology.(2015 Sep)
- ADHD Symptoms - Voigt RG, Llorente AM, Jensen CL, Fraley JK, Berretta MC, Heird WCA randomized, double-blind, placebo-controlled trial of docosahexaenoic acid supplementation in children with attention-deficit/hyperactivity disorderJ Pediatr.(2001 Aug)
- ADHD Symptoms - Gustafsson PA, Birberg-Thornberg U, Duchén K, Landgren M, Malmberg K, Pelling H, Strandvik B, Karlsson TEPA supplementation improves teacher-rated behaviour and oppositional symptoms in children with ADHDActa Paediatr.(2010 Oct)
- ADHD Symptoms - Stevens L, Zhang W, Peck L, Kuczek T, Grevstad N, Mahon A, Zentall SS, Arnold LE, Burgess JREFA supplementation in children with inattention, hyperactivity, and other disruptive behaviorsLipids.(2003 Oct)
- ADHD Symptoms - Widenhorn-Müller K, Schwanda S, Scholz E, Spitzer M, Bode HEffect of supplementation with long-chain ω-3 polyunsaturated fatty acids on behavior and cognition in children with attention deficit/hyperactivity disorder (ADHD): a randomized placebo-controlled intervention trialProstaglandins Leukot Essent Fatty Acids.(2014 Jul-Aug)
- ADHD Symptoms - Bloch MH, Qawasmi AOmega-3 fatty acid supplementation for the treatment of children with attention-deficit/hyperactivity disorder symptomatology: systematic review and meta-analysisJ Am Acad Child Adolesc Psychiatry.(2011 Oct)
- ADHD Symptoms - Sinn N, Bryan JEffect of supplementation with polyunsaturated fatty acids and micronutrients on learning and behavior problems associated with child ADHDJ Dev Behav Pediatr.(2007 Apr)
- ADHD Symptoms - Bélanger SA, Vanasse M, Spahis S, Sylvestre MP, Lippé S, L'heureux F, Ghadirian P, Vanasse CM, Levy EOmega-3 fatty acid treatment of children with attention-deficit hyperactivity disorder: A randomized, double-blind, placebo-controlled studyPaediatr Child Health.(2009 Feb)
- ADHD Symptoms - Alisha Bruton, Joy Nauman, Douglas Hanes, Melissa Gard, Angela SendersPhosphatidylserine for the Treatment of Pediatric Attention-Deficit/Hyperactivity Disorder: A Systematic Review and Meta-AnalysisJ Altern Complement Med.(2021 Feb 4)
- ADHD Symptoms - Arnold LE, Disilvestro RA, Bozzolo D, Bozzolo H, Crowl L, Fernandez S, Ramadan Y, Thompson S, Mo X, Abdel-Rasoul M, Joseph EZinc for attention-deficit/hyperactivity disorder: placebo-controlled double-blind pilot trial alone and combined with amphetamineJ Child Adolesc Psychopharmacol.(2011 Feb)
- ADHD Symptoms - Talebi S, Miraghajani M, Ghavami A, Mohammadi HThe effect of zinc supplementation in children with attention deficit hyperactivity disorder: A systematic review and dose-response meta‑analysis of randomized clinical trials.Crit Rev Food Sci Nutr.(2022)
- ADHD Symptoms - Ruth E Cooper, Emma Williams, Seth Seegobin, Charlotte Tye, Jonna Kuntsi, Philip AshersonCannabinoids in attention-deficit/hyperactivity disorder: A randomised-controlled trialEur Neuropsychopharmacol.(2017 Aug)
- ADHD Symptoms - Sara Baziar, Ali Aqamolaei, Ebrahim Khadem, Seyyed Hosein Mortazavi, Sina Naderi, Erfan Sahebolzamani, Amirhosein Mortezaei, Shakiba Jalilevand, Mohammad-Reza Mohammadi, Mahsa Shahmirzadi, Shahin AkhondzadehCrocus sativus L. Versus Methylphenidate in Treatment of Children with Attention-Deficit/Hyperactivity Disorder: A Randomized, Double-Blind Pilot StudyJ Child Adolesc Psychopharmacol.(2019 Apr)
- ADHD Symptoms - Hae-Jin Ko, Inbo Kim, Jong-Bae Kim, Yong Moon, Min-Cheol Whang, Keun-Mi Lee, Seung-Pil JungEffects of Korean red ginseng extract on behavior in children with symptoms of inattention and hyperactivity/impulsivity: a double-blind randomized placebo-controlled trialJ Child Adolesc Psychopharmacol.(2014 Nov)
- ADHD Symptoms - Salehi B, Imani R, Mohammadi MR, Fallah J, Mohammadi M, Ghanizadeh A, Tasviechi AA, Vossoughi A, Rezazadeh SA, Akhondzadeh SGinkgo biloba for attention-deficit/hyperactivity disorder in children and adolescents: a double blind, randomized controlled trialProg Neuropsychopharmacol Biol Psychiatry.(2010 Feb 1)
- ADHD Symptoms - Surman C, Vaudreuil C, Boland H, Rhodewalt L, DiSalvo M, Biederman JL-Threonic Acid Magnesium Salt Supplementation in ADHD: An Open-Label Pilot Study.J Diet Suppl.(2021)
- Attention - Susan Kennel, Ann Gill Taylor, Debra Lyon, Cheryl BourguignonPilot feasibility study of binaural auditory beats for reducing symptoms of inattention in children and adolescents with attention-deficit/hyperactivity disorderJ Pediatr Nurs.(2010 Feb)
- Sleep Quality - Lyon MR, Kapoor MP, Juneja LRThe effects of L-theanine (Suntheanine®) on objective sleep quality in boys with attention deficit hyperactivity disorder (ADHD): a randomized, double-blind, placebo-controlled clinical trialAltern Med Rev.(2011 Dec)