Whether you are an adult, adolescent or child, ADHD is NOT a myth - it impacts self-esteem, relationships, work-life, and school-life.

The Centre for ADHD is dedicated to providing support services designed to assist you in living well with ADHD.

We offer a full range of services including:

· ADHD Assessments

· Skill Development Groups

· Coaching

· Lifestyle Strategies

· Mindfulness

· Goal Setting

· Psychoeducation

· Healthy Communication

· Interpersonal Effectiveness

· Relationship Building

Many people have heard of ADHD.

It may make you think of kids who have trouble paying attention or who are hyperactive or impulsive. Adults can have ADHD, too. About 4% to 5% of U.S. adults have it. But few adults get diagnosed or treated for it.

Who gets adult ADHD? Every adult who has ADHD had it as a child. Some may have been diagnosed and known it. But some may have not been diagnosed when they were young and only find out later in life.

While some kids with ADHD outgrow it, about 60% to 80% of children who are diagnosed with ADHD will still have symptoms when they are teens or adults, although their symptoms may become less obvious over time. Adult ADHD appears to affect men and women equally.

ADHD Runs in Families and is Highly Heritable

The first hint that genetic factors may play a role in ADHD came from research findings indicating that ADHD runs in families. For instance, compared to their non-ADHD peers, students with ADHD are two to eight times more likely to have at least one sibling with ADHD and to have a parent with ADHD, although the symptoms of ADHD may never have been identified or formally diagnosed in the family members.

Family studies cannot separate the effect of genes from possible environmental factors. To directly estimate the heritability of ADHD, twins need to be studied. Monozygotic ("identical") twins share 100% of their genes, whereas dizygotic ("fraternal") twins, like other siblings, share about 50% of their genes on average. Researchers determine the extent to which identical twins are concordant for ADHD (that is, the chance that if one twin has ADHD, the other will as well) and compare this to the rate in fraternal twins. From this information, researchers can then compute the heritability of ADHD, or the degree to which variability in ADHD in the population can be accounted for by genes. The mean heritability estimate for ADHD across about 20 twin studies is roughly 80%, indicating that ADHD is highly heritable — almost as heritable as height!

From the school perspective, these findings mean that if a student with ADHD has siblings, one or more of the other siblings are likely to also have ADHD. But siblings with ADHD may show very different profile of ADHD symptoms and also may have different types of problems at school (for example, one sibling may have concurrent reading disabilities, whereas the other sibling may have additional problems with aggression or non-compliance). Thus, what worked for teaching and managing classroom behaviour for one of the siblings may not be effective with the other; a functional assessment of each student's strengths and difficulties is always required. It is also possible that one of the parents of the student with ADHD may have ADHD themselves. ADHD in adulthood poses additional challenges for parenting, particularly if both parent and child have ADHD.

Genetic Factors in ADHD

The high heritability of ADHD has stimulated investigations into the molecular genetic basis of ADHD. Converging evidence from pharmacological, neuroimaging, and animal research has focused the molecular genetic research primarily on genes involved in specific neurotransmitter systems, particularly the dopamine system. At the time this website was created, there have been only a few genome-wide scans and no specific chromosomal region has been implicated unequivocally. Nonetheless, considerable progress has been made and several genes have been identified that increase the susceptibility to ADHD, including the dopamine D4 receptor gene (DRD4), the dopamine transporter gene (DAT1), and the dopamine D5 receptor (DRD5), as well as genes associated with the other neurotransmitters (noradrenaline, serotonin), and synaptosomal proteins, such as the SNAP-25 protein. However, these genes confer only a small additional risk of ADHD on their own and the general belief is that this complex disorder involves multiple genes of small to moderate effect. Researchers are now beginning to investigate how such genes work together and how they interact with environmental factors to influence behaviour. Researchers are also trying to identify patterns of genetic variation that may make it possible to develop individually tailored pharmacological treatments for this disorder.

Environmental Factors contribute to ADHD

Twin studies indicate not only that ADHD is highly heritable, but also that 10% to 25% of the variance in the ADHD phenotype is accounted for mostly by non-shared environmental factors, and that shared environmental factors play only a small role in increasing the risk for ADHD.

Pregnancy, labour and delivery, and neonatal complications are associated with an increased risk for ADHD in childhood. Problems in the neonatal period, such as the need for an incubator, oxygen therapy, or surgery, are more common in children with ADHD than in their siblings, suggesting that neonatal complications may be a non-shared environmental risk factor. Other perinatal problems (that is, problems relating to the period around childbirth, especially the five months before, during, and one month after birth), such as prenatal exposure to nicotine or alcohol, prematurity, and low birth weight, are also associated with increased risk for ADHD and academic difficulties. For example, children of mothers who smoke during pregnancy are more likely to be rated by parents and teachers as exhibiting symptoms of inattention (or ADHD) and to exhibit lower academic achievement and poorer visuo-spatial reasoning. Also, children with ADHD are 2.5 times more likely to have been exposed to alcohol in utero and 2 times more likely to be exposed prenatally to cigarette smoke than non-ADHD control subjects. Moreover, maternal smoking during pregnancy is associated with lower levels of specific neurotransmitters (such as dopamine) in the fetus and elevated risk for subsequent nicotine dependence in adulthood in the offspring. However, the link between maternal smoking in pregnancy and increased risk for ADHD in the offspring may be shared family risks that interact to some degree with genetics.

Some toxic chemicals in the environment are known to interfere with the same aspects of behaviour and learning that are atypical in ADHD, and so are also thought to play a causal role. Lead is the best-studied example of an environmental contaminant that interferes with learning. Exposure to lead causes reductions in IQ and has also been linked to reading and learning disabilities, disruptive behaviour in the classroom, and reduced ability to pay attention. Lead exposure is also associated with increased risk for antisocial and delinquent behaviour in childhood and is a predictor of adult criminality.

Other toxic chemicals that have been shown to interfere with children's learning are the polychlorinated biphenyls (PCBs), chemical insulators that were widely used by industry until their ban in the U.S. in 1976 and that persist in the environment and in human tissue. Children are exposed to PCBs through breast milk and by eating fish and other fatty foods that contain high concentrations of PCBs. Children can also be exposed in utero, as PCBs move across the placenta. Exposure to high levels of PCBs has been shown to interfere with many aspects of cognitive development, including lower full-scale and verbal IQ scores as well as significant attention and memory deficits.



·       U.S. Department of Education, Office of Special Education and Rehabilitative Services, Office of Special Education Programs (2003). Identifying and Treating Attention Deficit Hyperactivity Disorder: A Resource for School and Home. Washington, D.C., 20202. Retrieved November 16, 2005, from

·         2 Weyandt, L.L., Iwaszuk, W., Fulton, K., et al. (2003). The internal restlessness scale: performance of college students with and without ADHD. Journal of Learning Disabilities, 36, 382-389.

·         3 Biederman, J., Mick, E., & Faraone, S.V. (2000). Age-dependent decline of symptoms of attention deficit hyperactivity disorder: impact of remission definition and symptom type. American Journal of Psychiatry, 157, 816-818.

·         4 Warner-Rogers, J., Taylor, A., Taylor, E., & Sandberg, S. (2000). Inattentive behavior in childhood: epidemiology and implications for development. Journal of Learning Disabilities, 33, 520-536.

·         5 Rabiner, D., & Coie, J.D. (2000). Early attention problems and children's reading achievement: a longitudinal investigation. The Conduct Problems Prevention Research Group. Journal of the American Academy of Child and Adolescent Psychiatry, 39, 859-867.

·         6 Curry, J., & Stabile, M. (2004). Child Mental Health and Human Capital Accumulation: The Case of ADHD. National Bureau of Economic Research; Working Paper 10435. Retrieved November 16, 2005, from

·         7 Carroll, J.M., Maughan, B., Goodman, R., & Meltzer, H. (2005). Literacy difficulties and psychiatric disorders: evidence for comorbidity. Journal of Child Psychology and Psychiatry, 46, 524-532.

·         8 Harpin, V.A. (2005). The effect of ADHD on the life of an individual, their family, and community from preschool to adult life. Archives of Disease in Childhood, 90(1 Suppl), i2-i7.

·         9 Becker, K., Holtmann, M., Laucht, M., & Schmidt, M.H. (2004). Are regulatory problems in infancy precursors of later hyperkinetic symptoms? Acta Paediatrica, 93, 1463-1469.

·         10 Sato, M., Aotoni, H., Hattori, R., & Funato, M. (2004). Behavioral outcome including attention deficit hyperactivity disorder/hyperactivity disorder and minor neurological signs in perinatal high-risk newborns at 4-6 years of age with relation to risk factors. Pediatrics International, 46, 346-352.

·         11 Auerbach, J.G., Atzaba-Poria, N., Berger, A., & Landau, R. (2004). Emerging developmental pathways to ADHD: possible path markers in early infancy. Neural Plasticity, 11, 29-43.

·         12 Lavigne, J.V., Gibbons, R.D., Christoffel, K.K., et al. (1996). Prevalence rates and correlates of psychiatric disorders among preschool children. Journal of the American Academy of Child and Adolescent Psychiatry, 35, 204-214.

·         13 Spira, E.G., & Fischel, J.E. (2005). The impact of preschool inattention, hyperactivity, and impulsivity on social and academic development: a review. Journal of Child Psychology and Psychiatry, 46, 755-773.

·         14 Larsson, J.O., Bergman, L.R., Earls, F., & Rydelius, P.A. (2004). Behavioral profiles in 4-5 year-old children: normal and pathological variants. Child Psychiatry and Human Development, 35, 143-162.

·         15 Kalff, A.C., De Sonneville, L.M., Hurks, P.P., et al. (2005). Speed, speed variability, and accuracy of information processing in 5 to 6-year-old children at risk of ADHD. Journal of the International Neuropsychological Society, 11, 173-183.

·         16 Weiss, M., & Jain, U. (2000). Clinical perspectives on the assessment of ADHD in adolescence. The ADHD Report, 8, 4-7.

·         17 Zentall S.S. (1988). Production deficiencies in elicited language but not in the spontaneous verbalizations of hyperactive children. Journal of Abnormal Child Psychology, 16, 657-673.

·         18 Brook, U., & Boaz, M. (2005). Attention deficit and hyperactivity disorder (ADHD) and learning disabilities (LD): adolescents perspective. Patient Education and Counseling, 58, 187-191.

·         19 Hoza, B., Mrug, S., Gerdes, A.C., et al. (2005). What aspects of peer relationships are impaired in children with attention-deficit/hyperactivity disorder? Journal of Consulting and Clinical Psychology, 73, 411-423.

·         20 Blachman, D.R., & Hinshaw, S.P. (2002). Patterns of friendship among girls with and without attention-deficit/hyperactivity disorder. Journal of Abnormal Child Psychology, 30, 625-640.

·         21 Mayes, S.D., Calhoun, S.L., & Crowell, E.W. (2000). Learning disabilities and ADHD: overlapping spectrumn disorders. Journal of Learning Disabilities, 33, 417-424.

·         22 Rowe, R., Maughan, B., & Goodman, R. (2004). Childhood psychiatric disorder and unintentional injury: findings from a national cohort study. Journal of Pediatric Psychology, 29, 119-130.

·         23 Brehaut, J.C., Miller, A., Raina, P., & McGrail, K.M. (2003). Childhood behavior disorders and injuries among children and youth: a population-based study. Pediatrics, 111, 262-269.

·         24 Todd, R.D., Sitdhiraksa, N., Reich, W., et al. (2002). Discrimination of DSM-IV and latent class attention-deficit/hyperactivity disorder subtypes by educational and cognitive performance in a population-based sample of child and adolescent twins. Journal of the American Academy of Child and Adolescent Psychiatry, 41, 820-828.

·         25 Whalen, C.K., Jamner, L.D., Henker, B., et al. (2002). The ADHD spectrum and everyday life: experience sampling of adolescent moods, activities, smoking, and drinking. Child Development, 73, 209-227.

·         26 Mannuzza, S., Klein, R.G., & Moulton, J.L. 3rd. (2002). Young adult outcome of children with "situational" hyperactivity: a prospective, controlled follow-up study. Journal of Abnormal Child Psychology, 30, 191-198.

·         27 Galera, C., Fombonne, E., Chastang, J.F., & Bouvard, M. (2005). Childhood hyperactivity-inattention symptoms and smoking in adolescence. Drug and Alcohol Dependence, 78, 101-108.

·         28 Kollins, S.H., McClernon, F.J., & Fuemmeler, B.F. (2005). Association between smoking and attention-deficit/hyperactivity disorder symptoms in a population-based sample of young adults. Archives of General Psychiatry, 62, 1142-1147.

·         29 Wilens, T.E., & Biederman, J. (2005). Alcohol, drugs, and attention-deficit/ hyperactivity disorder: a model for the study of addictions in youth. Journal of Psychopharmacology, Sep 20, [Epub ahead of print]

·         30 Barkley, R.A. (2002). Major life activity and health outcomes associated with attention-deficit/hyperactivity disorder. Journal of Clinical Psychiatry, 63(12 Suppl), 10-15.

·         31 Barkley, R.A., Fischer, M., Smallish, L., & Fletcher, K. (2004). Young adult follow-up of hyperactive children: antisocial activities and drug use. Journal of Child Psychology and Psychiatry, 45, 195-211.

·         32 Barkley, R.A. (2004). Driving impairments in teens and adults with attention-deficit/hyperactivity disorder. Psychiatric Clinics of North America, 27, 233-260.

·         33 DuPaul, G.J., Schaughency, E.A., Weyandt, L.L., et al. (2001). Self-report of ADHD symptoms in university students: cross-gender and cross-national prevalence. Journal of Learning Disabilities, 34, 370-379.

·         34 Wolf, L.E. (2001). College students with ADHD and other hidden disabilities. Outcomes and interventions. Annals of the New York Academy of Sciences, 931, 385-395.

·         35 Shaw-Zirt, B., Popali-Lehane, L., Chaplin, W., & Bergman, A. (2005). Adjustment, social skills, and self-esteem in college students with symptoms of ADHD. Journal of Attention Disorders, 8, 109-120.

·         36 Canu, W.H., & Carlson, C.L. (2003). Differences in heterosocial and behavior outcomes of ADHD-symptomatic subtypes in a college sample. Journal of Attention Disorders, 6, 123-133.

·         37 Heiligenstein, E., Guenther, G., Levy, A., et al. (1999). Psychological and academic functioning in college students with attention deficit hyperactivity disorder. Journal of American College Health, 47, 181-185.

·         38 Kessler, R.C., Adler, L., Ames, M., et al. (2005). The prevalence and effects of adult attention deficit/hyperactivity disorder on work performance in a nationally representative sample of workers. Journal of Occupational and Environmental Medicine, 47, 565-572.

·         39 Riccio, C.A., Wolfe, M., Davis, B., et al. (2005). Attention deficit hyperactivity disorder: manifestation in adulthood. Archives of Clinical Neuropsychology, 20, 249-269.

·         40 Wilens, T.E., & Dodson, W. (2004). A clinical perspective of attention-deficit/hyperactivity disorder into adulthood. Journal of Clinical Psychiatry, 65, 1301-1313.

·         41 Hervey, A.S., Epstein, J.N., & Curry, J.F. (2004). Neuropsychology of adults with attention-deficit/hyperactivity disorder: a meta-analytic review. Neuropsychology, 18, 485-503.

·         42 Swensen, A., Birnbaum, H.G., Ben Hamadi, R., et al. (2004). Incidence and costs of accidents among attention-deficit/hyperactivity disorder patients. Journal of Adolescent Health, 35, 346.e1-9.

·         43 Harvey, E., Danforth, J.S., McKee, T.E., et al. (2003). Parenting of children with attention-deficit/hyperactivity disorder (ADHD): the role of parental ADHD symptomatology. Journal of Attention Disorders, 7, 31-42.

·         44 Montgomery, D.J. (2005). Communicating without harm: strategies to enhance parent-teacher communication. Teaching Exceptional Children, 37(May/June), 50-55.

·         45 Hoffmann, H. (1995). Struwwelpeter: In English Translation. New York: Dover Publication.

·         46 Still, G.F. (1902). Some abnormal psychical conditions in children: the Goulstonian lectures. Lancet, 1, 1008-1012, 1077-1082.

·         47 American Psychiatric Association (2000). Diagnostic and Statistical Manual of Mental Disorders, 4th Edition, Text Revision (DSM-IV-TR). Washington, D.C.: American Psychiatric Association.

·         48 Krummel, D.A., Seligson, F.H., & Guthrie, H.A. (1996). Hyperactivity: is candy causal? Critical Reviews in Food Science and Nutrition, 36, 31-47.

·         49 Wolraich, M.L., Wilson, D.B., & White, J.W. (1995). The effect of sugar on behavior or cognition in children. A meta-analysis. Journal of the American Medical Association, 274, 1617-1621.

·         50 Bateman, B., Warner, J.O., Hutchinson, E., et al. (2004). The effects of a double blind, placebo controlled, artificial food colourings and benzoate preservative challenge on hyperactivity in a general population sample of preschool children. Archives of Disease in Childhood, 89, 506-511.

·         51 Steer, C.R. (2005). Managing attention deficit/hyperactivity disorder: unmet needs and future directions. Archives of Disease in Childhood, 90(1 Suppl), i19-i25.

·         52 Johnston, C., Seipp, C., Hommersen, P., et al. (2005). Treatment choices and experiences in attention deficit and hyperactivity disorder: relations to parents' beliefs and attributions. Child: Care, Health and Development, 31, 669-677.

·         53 Miranda, A., Presentacion, M.J., & Soriano, M. (2002). Effectiveness of a school-based multicomponent program for the treatment of children with ADHD. Journal of Learning Disabilities, 35, 546-562.

·         54 DuPaul, G.J., & Eckert, T.L. (1998). Academic interventions for students with attention-deficit hyperactivity disorder: a review of the literature. Reading and Writing Quarterly: Overcoming Learning Disabilities, 14, 59-82.

·         55 Salend, S.J., Elhoweris, H., & van Garderen, D. (2003). Educational interventions for students with ADD. Intervention in School and Clinic, 38, 280-288.

·         56 Tannock, R., & Martinussen, R. (2001). Reconceptualizing ADHD. Educational Leadership, 59, 20-25, [2002 Distinguished Achievement Award for Excellence in Educational Publishing, Association of Educational Publishers, USA].

·         57 Williams, R.A., Horn, S., Daley, S.P., & Nader, P.R. (1993). Evaluation of access to care and medical and behavioral outcomes in a school-based intervention program for attention-deficit hyperactivity disorder. Journal of School Health, 63, 294-297.

·         58 US Department of Education, Office of Special Education and Rehabilitative Services, Office of Special Education Programs. Teaching Children with Attention Deficit Hyperactivity Disorder: Instructional Strategies and Practices. Washington, D.C. Retrieved August, 2005, from

·         59 Faraone, S.V., & Biederman, J. (1994). Is attention deficit hyperactivity disorder familial? Harvard Review of Psychiatry, 1, 271-287.

·         60 Faraone, S.V., Perlis, R.H., Doyle, A.E., et al. (2005). Molecular genetics of attention-deficit/hyperactivity disorder. Biological Psychiatry, 57, 1313-1323.

·         61 Chronis, A.M., Lahey, B.B., Pelham, W.E. Jr., et al. (2003). Psychopathology and substance abuse in parents of young children with attention-deficit/hyperactivity disorder. Journal of the American Academy of Child and Adolescent Psychiatry, 42, 1424-1432.

·         62 Thapar, A., O'Donovan, M., & Owen, M.J. (2005). The genetics of attention deficit hyperactivity disorder. Human Molecular Genetics, 14, R275-R282.

·         63 McGough, J.J. (2005). Attention-deficit/hyperactivity disorder pharmacogenomics. Biological Psychiatry, 57, 1367-1373.

·         64 Knopik, V.S., Sparrow, E.P., Madden, P.A., et al. (2005). Contributions of parental alcoholism, prenatal substance exposure, and genetic transmission to child ADHD risk: a female twin study. Psychological Medicine, 35, 625-635.

·         65 Linnet, K.M., Dalsgaard, S., Obel, C., et al. (2003). Maternal lifestyle factors in pregnancy risk of attention deficit hyperactivity disorder and associated behaviors: review of the current evidence. American Journal of Psychiatry, 160, 1028-1040.

·         66 Ben Amor, L., Grizenko, N., Schwartz, G., et al. (2005). Perinatal complications in children with attention-deficit hyperactivity disorder and their unaffected siblings. Journal of Psychiatry and Neuroscience, 30, 120-126.

·         67 Huizink, A.C., & Mulder, E.J. (2005). Maternal smoking, drinking or cannabis use during pregnancy and neurobehavioral and cognitive functioning in human offspring. Neuroscience and Biobehavioral Reviews, Aug 8, [Epub ahead of print]

·         68 Taylor, E., & Rogers, J.W. (2005). Practitioner review: early adversity and developmental disorders. Journal of Child Psychology and Psychiatry, 46, 451-467.

·         69 Batstra, L., Hadders-Algra, M., & Neeleman, J. (2003). Effect of antenatal exposure to maternal smoking on behavioural problems and academic achievement in childhood: prospective evidence from a Dutch birth cohort. Early Human Development, 75, 21-33.

·         70 Thapar, A., Fowler, T., Rice, F., et al. (2003). Maternal smoking during pregnancy and attention deficit hyperactivity disorder symptoms in offspring. American Journal of Psychiatry, 160, 1985-1989.

·         71 Yolton, K., Dietrich, K., Auinger, P., et al. (2005). Exposure to environmental tobacco smoke and cognitive abilities among U.S. children and adolescents. Environmental Health Perspectives, 113, 98-103.

·         72 Roberts, K.H., Munafo, M.R., Rodriguez, D., et al. (2005). Longitudinal analysis of the effect of prenatal nicotine exposure on subsequent smoking behavior of offspring. Nicotine and Tobacco Research, 7, 801-808.

·         73 Oncken, C., McKee, S., Krishnan-Sarin, S., et al. (2004). Gender effects of reported in utero tobacco exposure on smoking initiation, progression and nicotine dependence in adult offspring. Nicotine and Tobacco Research, 6, 829-833.

·         74 Oncken, C.A., Henry, K.M., Campbell, W.A., et al. (2003). Effect of maternal smoking on fetal catecholamine concentrations at birth. Pediatric Research, 53, 119-124.

·         75 Muir, T., & Zegarac, M. (2001). Societal costs of exposure to toxic substances: economic and health costs of four case studies that are candidates for environmental causation. Environmental Health Perspectives, 109(6 Suppl), 885-903.

·         76 Stein, J., Schettler, T., Wallinga, D., & Valenti, M. (2002). In harm's way: toxic threats to child development. Journal of Developmental and Behavioral Pediatrics, 23(1 Suppl), S13-S22.

·         77 Tannock, R. (1998). Attention deficit hyperactivity disorder: advances in cognitive, neurobiological, and genetic research. Journal of Child Psychology and Psychiatry, 39, 65-99.

·         78 Bush, G., Valera, E.M., & Seidman, L.J. (2005). Functional neuroimaging of attention-deficit/hyperactivity disorder: a review and suggested future directions. Biological Psychiatry, 57, 1273-1284.

·         79 Durston, S. (2003). A review of the biological bases of ADHD: what have we learned from imaging studies? Mental Retardation and Developmental Disabilities Research Reviews, 9, 184-195.

·         80 Castellanos, F.X., Lee, P.P., Sharp, W., et al. (2002). Developmental trajectories of brain volume abnormalities in children and adolescents with attention-deficit/hyperactivity disorder. Journal of the American Medical Association, 288, 1740-1748.

·         81 Konrad, K., Neufang, S., Hanisch, C., et al. (2005). Dysfunctional attentional networks in children with attention deficit/hyperactivity disorder: evidence from an event-related functional magnetic resonance imaging study. Biological Psychiatry, Sept 27, [Epub ahead of print]

·         82 Silk, T., Vance, A., Rinehart, N., et al. (2005). Fronto-parietal activation in attention-deficit hyperactivity disorder, combined type: functional magnetic resonance imaging study. British Journal of Psychiatry, 187, 282-283.

·         83 Mostofsky, S.H., Rimrodt, S.L., Schafer, J.G., et al. (2005). Atypical motor and sensory cortex activation in attention-deficit/hyperactivity disorder: a functional magnetic resonance imaging study of simple sequential finger tapping. Biological Psychiatry, Aug 31, [Epub ahead of print]

·         84 Ashtari, M., Kumra, S., Bhaskar S.L., et al. (2005). Attention-deficit/hyperactivity disorder: a preliminary diffusion tensor imaging study. Biological Psychiatry, 57, 448-455.