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Risk Factors and Causes

Genetic causes get their own page.  Many other risk factors and causes are listed below.  These include very low birth weight, tuberculous meningitis, snoring, head trauma, alcohol and tobacco and drug abuse during pregnancy, lead poisoning, iron deficiency, velocardiofacial syndrome, PCB exposure, seizure disorders, sugared soda, television, videogames, etc.

ADHD Have Smaller Brains: Very small study, 12 ADHD boys and 12 controls. Boys with ADHD had (on average) 8.3% smaller total cerebral volumes. Significant reductions in lobar volumes were seen only for the frontal lobes. Smaller prefrontal and premotor volumes in boys with attention-deficit/hyperactivity disorder. Mostofsky SH, Cooper KL, Kates WR, Denckla MB, Kaufmann WE.

ADHD Smaller Brains Throughout Life: 152 children ADHD (5-18 years) and 139 controls. On initial scan, ADHD pts smaller brain volumes in all regions; smaller total cerebral volumes (-3.2%), smaller cerebellar volumes (-3.5%). Compared with controls, previously unmedicated children with ADHD demonstrated significantly smaller total cerebral volumes (-5.8%) and cerebellar volumes (-6.2%). Unmedicated children with ADHD also exhibited strikingly smaller total white matter (-10.7%, P<.001) and with medicated children with ADHD (-8.9%, P<.001). Volumetric abnormalities persisted with age. Caudate nucleus volumes were initially abnormal for patients with ADHD (P =.05), but diagnostic differences disappeared as caudate volumes decreased for patients and controls during adolescence. Frontal and temporal gray matter, caudate, and cerebellar volumes correlated significantly with parent- and clinician-rated severity measures within the ADHD sample. Genetic and/or early environmental influences on brain development in ADHD are fixed, nonprogressive, and unrelated to stimulant treatment. Developmental trajectories of brain volume abnormalities in children and adolescents with attention-deficit/hyperactivity disorder. Castellanos FX, Lee PP, Sharp W, Jeffries NO, Greenstein DK, Clasen LS, Blumenthal JD, James RS, Ebens CL, Walter JM, Zijdenbos A, Evans AC, Giedd JN, Rapoport JL. NIMH Study. JAMA 2002 Oct 9;288(14):1740-8

Causes and Risk Factors

ADHD Kids with Schizophrenic Relatives at Risk for Schizophrenia: Study of 29 kids with schizophrenic relatives and 29 without found that 10 of the 29 with schizophrenic relatives were ADHD and these had the highest rate of preschizophrenic psychological symptoms, e.g. belief in good luck charms and reporting body parts sometimes feeling dead. 10 other of the 29 had other diagnoses and were intermediate. Matcheri Keshavan, Univ Pittsburgh, January 2003 Schizophrenia Research.

Artificial Coloring and Sodium Benzoate Cause Slight Hyperactivity in Children Regardless of ADHD Status: 277 of 1,873 children age 3 all of whom had been screened in their fourth year for the presence of hyperactivity at baseline (HA), of whom 1,246 had skin prick tests to identify atopy (AT) were selected for a careful DB PC crossover study in which children received one week of a special diet with a drink containing artificial colorings (20 mg daily) and sodium benzoate (45 mg daily) (active period), or a placebo mixture, supplementary to their diet. There were significant reductions in hyperactive behavior during the withdrawal phase. Furthermore, there were significantly greater increases in hyperactive behavior during the active than the placebo period based on parental reports. These effects were not influenced by the presence or absence of hyperactivity, nor by the presence or absence of atopy. There were no significant differences detected based on objective testing in the clinic. 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. BatemanB, WarnerJO, HutchinsonE, DeanT, RowlandsonP, GantC, GrundyJ, FitzgeraldC & StevensonJ. (2004) Archives of Disease in Childhood, 89, 506-511. Also, Child Care Health Dev. 2004 Sep;30(5):561 

Alcohol: Prenatal Exposure Increases ADHD Behavior in Children and Rats: Children with fetal alcohol spectrum disorder are often diagnosed with attention-deficit/ hyperactivity disorder. Rats with prenatal ethanol exposure show attention deficits that are similar to those of children with FASD and ADHD. Prenatal alcohol exposure causes attention deficits in male rats. Hausknecht KA, et al. State University of New York, Buffalo. Behav Neurosci. 2005 Feb;119(1):302-10.

Birth Factors Play No Role in ADHD, But Parental Education was Inversely Associated: In a case-control study of 5701 children including all born in a single Minnesota county of 7 years, 305 children had been diagnosed with ADHD. Pregnancy and labor characteristics, low birth weight, and presence of a twin birth were not associated with ADHD. Male sex (odds ratio [OR], 3.05) was associated with a tripled risk for ADHD, whereas high maternal and paternal education levels (high maternal education: OR, 0.57; high paternal education: OR, 0.58) were associated with a considerably decreased risk for ADHD. In addition, low maternal and paternal education levels increased the risk for ADHD in boys more than in girls. Early life risk factors for attention-deficit/hyperactivity disorder: a population-based cohort study. St Sauver JL, Barbaresi WJ, Katusic SK, Colligan RC, Weaver AL, Jacobsen SJ. Mayo Clinic. Mayo Clin Proc. 2004 Sep;79(9):1124-31. 

Caffeine Can Cause Mild Hyperactivity in Children: In a 2-week DB PC crossover study of 20 1st-graders, on the days the children were given caffeined beverages (10 oz.), there was impaired learning ability by causing restlessness, hyperactivity, and inattention with their Connors scores increased an average of 5.5 points compared with the days when they were only drinking caffeine-free drinks (P = .03). On the days without caffeine, the children had an average modified Connors score of 1.55. Among the individual students, 60% had elevated Connors scores on the caffeine days, while 15% had higher scores on the caffeine-free days (P = .008). After adjusting for noncaffeine-related factors, such as the number of ounces consumed and the amount of sugar in the drinks, the scores were still higher on the caffeine days (P = .015). Children ages 6 to 11 years old conservatively drink an average of seven to eight oz of carbonated soda per day. This can have a substantial impact on children's behavior in school. Alan R. Hirsch, et al. APA Annual Meeting: Abstract NR45. May 23, 2005.

Classroom ADHD Behavior Much More Common than with Tutoring: A study of 30 children 100% of whom were rated as fulfilling ADHD criteria based on classroom behavior found that only 13% had enough ADHD behavior to receive such a diagnosis based upon behavior during tutoring sessions. Reduction in children's symptoms of attention deficit hyperactivity disorder and oppositional defiant disorder during individual tutoring as compared with classroom instruction. Strayhorn JM Jr, Bickel DD. Psychol Rep. 2002 Aug;91(1):69-80. Ed: Many classrooms in the U.S. use modified open classroom type arrangements, i.e., children facing each other, children allowed to get up and walk around, children permitted to change subjects at will, small groups of children working on their own without teacher control, disruptions caused by multiple teachers and disabled students, etc.  Open classrooms have repeatedly been shown to dramatically retard learning.  It appears that they also increase hyperactivity.

Genetics Explains Lower Intellectual Performance in ADHD Children: ADHD and lower IQ covary in children. In this large population-based sample of 5-year-old twins, the phenotypic correlation between ADHD symptom scores and IQ was -0.3 and, children with ADHD obtained IQ scores 9 points lower, on average, than comparison children. The co-occurrence of ADHD and lower IQ has genetic origins: 86% of the association between ADHD symptom scores and IQ, and 100% of the association between ADHD diagnosis and IQ, was accounted for by genetic influences that are shared by ADHD and IQ. Co-occurrence of ADHD and low IQ has genetic origins. Kuntsi J, Eley TC, et al. King's College London, United Kingdom. Am J Med Genet B Neuropsychiatr Genet. 2004 Jan 1;124(1):41-7. 

Glutamate in Brain High in ADHD: In a study of children with ADHD but off their medications for 24 hours, Johns Hopkins researchers found glutamate levels with 2 1/2 times higher than in children without ADHD. It couldn't be ruled out that the high levels were in some way related to the medication, although this was thought unlikely. H Courvoisie, J Neuropsychiatry Neurosciences 12/03.

Head Trauma Linked to Increased ADHD: In a 1-year follow-up of 103 children ages 3-14 with closed head trauma, 15% developed secondary ADHD. Some showed personality changes. Max JE, et al. UC, San Diego. J Am Acad Child Adolesc Psychiatry 2005;44-1041-9. Ed: Animal research strongly suggests that melatonin started immediately after the head trauma would probably markedly reduce this harmful event.

Iron Deficiency Common in ADHD: Iron deficiency causes abnormal dopaminergic neurotransmission. In a study of 53 French children with ADHD ages 4-14 and 27 controls, serum ferritin levels were lower in the children with ADHD (23 ng/mL) than in the controls (44 ng/mL; P < 0.001). Serum ferritin levels were abnormal (<30 ng/mL) in 84% of children with ADHD and 18% of controls (P < 0.001). Low serum ferritin levels were correlated with more severe general ADHD symptoms (P < 0.02) and greater cognitive deficits (P < 0.01). Iron deficiency in children with attention-deficit/hyperactivity disorder. Konofal E, Lecendreux M, et al. Archives of Pediatrics and Adolescent Medicine, 2004:158:1113-1115. 

Iron Treatment Might Have Helped: Iron plays a role in the regulation of dopaminergic activity. 14 boys with ADHD) received an iron preparation (Ferrocal), 5 mg/kg/day for 30 days. There was a significant increase in serum ferritin levels (from 25.9 to 44.6 ng/ml) and a significant decrease on the parents' Connors Rating Scale scores (from 17.6 to 12.7). There were no changes in other blood parameters or in the teachers' scores on the rating scale. Iron treatment in children with attention deficit hyperactivity disorder. A preliminary report. Sever Y, Ashkenazi A, et al. Sackler School of Medicine, Tel Aviv University, Israel. Neuropsychobiology. 1997;35(4):178-80.

Lead Level Elevation Rarely Found: Results obtained from 102 children revealed a sample mean blood lead level of 2.29 micrograms/dL and one patient with a mildly elevated blood lead level. Comparing these findings to results of national studies suggests that these children are not at higher risk for elevated lead levels. Mo Med. 1997 Jun;94(6):295-7.

Lead in Hair Linked to ADHD: 277 first-grade pupils, teachers completed the abbreviated Boston Teacher's Rating Scale for rating classroom attention-deficit behavior, and parents completed a short questionnaire. The children's hair lead concentrations ranged from less than 1 to 11.3 ppm (microg/g). The striking dose-response relationship between levels of lead and negative teacher ratings remained significant after controlling for age, ethnicity, gender, and socioeconomic status. An even stronger relationship existed between physician-diagnosed attention-deficit hyperactivity disorder and hair lead in the same children. Univ. Mass. Arch Environ Health. 1996 May-Jun;51(3):214-20; Similarly, in 43 children with problems, children with relatively high concentrations of lead in their hair reacted significantly slower in a simple reaction-time task than did children with relatively low concentrations of lead in their hair. In addition, the former were significantly less flexible in changing their focus of attention. J Learn Disabil. 1994 Jun-Jul;27(6):393-9.

Lead Linked to Aggression and Hyperactivity in Children: Blood-lead in 501 boys and girls age 6-9 from 18 primary schools found a significant relationship between blood-lead and teachers' ratings on aggressive/anti-social and hyperactive sub-scores, but not the neurotic sub-score when 30 possible confounding variables were taken into account. There was a dose-response relationship between blood-lead and behaviour ratings, with no evidence of a threshold. Blood-lead levels and children's behaviour--results from the Edinburgh Lead Study. Thomson GO, Raab GM, et al. University of Edinburgh, U.K. J Child Psychol Psychiatry. 1989 Jul;30(4):515-28.

Lead Linked to Inattention and Hyperactivity: Blood lead levels in 579 Dunedin 11-yr-old children were associated with a small but statistically significant increase in children's general behaviour problems, especially inattention and hyperactivity, as reported by both parents and teachers. Blood lead, intelligence, reading attainment, and behaviour in eleven year old children in Dunedin, New Zealand. Silva PA, Hughes P, et al. University of Otago Medical School, Dunedin, New Zealand. J Child Psychol Psychiatry. 1988 Jan;29(1):43-52.

Lead Weakly Linked to Hyperactivity: The hyperactive children had higher chelated urine lead levels than their own siblings. Cognitive performances and lead levels were weakly associated in the hyperactive sample. These results support the notion that lead levels are weakly associated with hyperactive disorders. Gittleman. Arch Gen Psychiatry. 1983 Aug;40(8):827-33.

Lead and Cadmium Hair Levels Reduced by Magnesium Supplementation: Magnesium deficiencies may cause increased accumulation of toxic metals including lead and cadmium. In a study of 124 adults in Szczecin, Poland, 65 had high lead levels and participated in a DB PC study. Those taking slow-Mag-B6 preparation at the total daily dose of five tablets divided into 2-3 doses (535 mg of magnesium chloride and 25 mg of vitamin B6 for 3 months had a decrease of lead and cadmium hair content. Magnesium and chosen bioelements in hair. Kozielec T, Salacka A, Karakiewicz B. Pomeranian Medical University, Szczecin, Poland. Magnes Res. 2004 Sep;17(3):183-8. 

Lead or PCB Exposure Cause Difficulties Similar to ADHD in Monkeys: Rice DC. National Center for Environmental Assessment. Environ Health Perspect. 2000 Jun;108 Suppl 3:405-8.

Low Birth Weight: VLBW Children High ADHD and Psychiatric Symptoms: In a population follow-up study of 56 very low birthweight (VLBW: birthweight </=1500 g), 60 term small for gestational age (SGA: birthweight <10th centile), and 83 normal term children at 14 years of age, the 46% of VLBW adolescents had psychiatric symptoms vs. 13% for controls or 470% more likely [OR 5.7] and psychiatric disorders 25% vs. 7% (OR 4.3), especially anxiety disorders. Attention problems were present in 25% of the VLBW adolescents with 7% diagnosed ADHD. Four had Asperger's disorder. Psychiatric symptoms and disorders in adolescents with low birthweight. Child Care Health Dev. 2005 Jan;31(1):121

Manganese in Soy Milk Possible Cause: Manganese 80 times higher in soy milk than breast milk and would be expensive to remove. Rat study by UC Davis in NeuroToxicology 8/02 found rats exposed to high manganese in infancy had behavioral problems. Industrial workers also get manganism with parkinson-like tremor and irritability with explosiveness. Surprisingly, I found no studies on PubMed since 1973 looking at ADHD rates and breast vs. bottle feeding.

Omega-3 Oxidation Factor May Be Elevated: In a very small, 10-patient preliminary study, exhalant ethane levels, a non-invasive measure of oxidative damage to n-3 fatty acids, was higher in ADHD children than in healthy volunteers (N = 12) with approximately 50% of ADHD cases being above the control range. In contrast, levels of butane, a marker of protein oxidation, were unaltered. It appears that some patients with ADHD have higher rates of oxidative breakdown of n-3 polyunsaturated fatty acids. Such a biochemical abnormality may underlie the previously observed fatty acid deficiencies, as well as providing further rationale for the use of anti-oxidant and/or lipid supplementation therapy in the treatment of ADHD. Increased levels of ethane, a non-invasive marker of n-3 fatty acid oxidation, in breath of children with attention deficit hyperactivity disorder. Ross BM, McKenzie I, Glen I, Bennett CP. Nutr Neurosci. 2003 Oct;6(5):277-81.

PCB Exposure Increases ADHD Symptoms in Those Not Breastfed: In a home interview study of 11-year-olds of children and with a chemical analysis of their cord blood from birth, adverse effects were seen primarily in children who had not been breast fed. Among these children, prenatal PCB exposure was associated with greater impulsivity, poorer concentration, and poorer verbal, pictorial, and auditory working memory. There was no evidence of visual-spatial deficit or increased hyperactivity. Wayne State. Prenatal exposure to polychlorinated biphenyls and attention at school age. Jacobson JL, Jacobson SW. J Pediatr. 2003 Dec;143(6):780-8

Preterm Children More ADHD: Children born prematurely, before the 32nd week of gestation, were found to have a much higher rate of motor difficulties at age 7 and also a higher rate of cognitive difficulties including ADHD. Motor, cognitive, and behavioural disorders in children born very preterm. Foulder-Hughes LA, Cooke RW. Dev Med Child Neurol. 2003 Feb;45(2):97-103; Another study found ADHD 164% more common among prematurely born children. Cognitive and behavioral outcomes of school-aged children who were born preterm: a meta-analysis. Bhutta AT, Cleves MA, Casey PH, Cradock MM, Anand KJ. JAMA. 2002 Aug 14;288(6):728-37

Seizure Disordered Children More ADHD: While the average rate of ADHD is 5%, studies of children with seizure disorders report rates of 8% to 77%. A Purdue study of 175 children with seizures for at least 6 months found 37% with ADHD with a predominance of inattentive (24%) and mixed types (12%). Primary caregiver completed both the Child Behavior Checklist (CBCL) and the Child Symptom Inventory-4 (CSI) or Adolescent Symptom Inventory-4 (ASI). ADHD and epilepsy in childhood. Dunn DW, Austin JK, Harezlak J, Ambrosius WT. Dev Med Child Neurol. 2003 Jan;45(1):50-4.

Sleep Apnea: If Not Snoring Plus Apneic Episodes of Daytime Sleepiness, OSA Appears Rare: In a small study of 41 children ages 6-14 with ADHD who did not have snoring plus either observed apneic episodes in sleep or excessive daytime sleepiness were evaluated with a polysomnogram. A respiratory disturbance index cut-off of more than 5 per hour of sleep was used to diagnose OSA, and a periodic limb movement (with arousal) index cut-off of 5 or more per hour of sleep was used to diagnose PLMD. No patient had OSA or PLMD on polysomnography. Patients with attention-deficit/hyperactivity disorder without observed apneic episodes in sleep or daytime sleepiness have normal sleep on polysomnography. Sangal RB, et al. Troy, Ml. . Sleep 2005 Sep 1;28(9):1143-8.

Snoring Linked to Hyperactive, Inattentiveness, Tiredness, Emotionality: In 1144 children, habitual snoring (HS; snoring frequently or always) and impaired behavior were assessed using parental questionnaires. Intermittent hypoxia was determined by pulse oximetry. HS was significantly associated with hyperactive (OR: 2.4) and inattentive behavior (OR: 4.0), daytime tiredness (OR: 7.1), and sleepiness (OR: 2.6-4.8). These associations were independent of intermittent hypoxia. HS was also significantly associated with bad conduct (OR: 2.8), emotional symptoms (OR: 5.5), and peer problems (OR: 9.7). At follow-up, hyperactive and inattentive behavior but not academic success had significantly improved in children in whom HS had ceased. Habitual snoring, intermittent hypoxia, and impaired behavior in primary school children. Urschitz MS, Eitner S, et al. University Children's Hospital, Tuebingen, Germany. Pediatrics. 2004 Oct;114(4):1041-8

Snoring Again Linked to ADHD in Children: In a study of 2147 children, 151 children with habitual snoring (HS) were compared to 302 controls. Children with ADHD were excluded. Of the remaining 96 habitual snorers and 190 control subjects (mean age: 9.4), HS had more symptoms of hyperactivity (Conners-ADHD index) (P: 0.033), attentional (P: 0.019), and conduct and oppositional defiant in subscales (P: 0.001) of Conners' Parent (Conners-P) and inattention hyperactivity scale (IHS)-Parents. A pooled score of Conners-P ADHD Index > 60 and IHS-Parent score > 1.25 showed considerable difference in HS when compared with controls (5.1% vs. 1.4%) (P < 0.0001). Daytime hyperactivity and excessive daytime sleepiness reported by parents correlated with scores of Conners-P and IHS-P (P < 0.01). Teachers' observations showed significant correlations with learning disability and the level of academic performance in HS (P < 0.01). Symptoms of inattention and hyperactivity in children with habitual snoring: evidence from a community-based study in Istanbul. Arman AR, et al. Marmara University, Istanbul, Turkey. Child Care Health Dev. 2005 Nov;31(6):707-17.

Stimulant Therapy Affects DR and DAT: Single Photon Emission Computed Tomography (SPECT) of 6 boys before and after 3 months of treatment found that methylphenidate down-regulated the post-synaptic dopamine receptor (DR) a maximum of 20 % and the dopamine transporter (DAT) with a maximum of 74.7 % in the striatal system. This corresponded to a positive clinical response evaluated by neuropsychological questionnaires and tests. Methylphenidate down-regulates the dopamine receptor and transporter system in children with attention deficit hyperkinetic disorder (ADHD). Vles JS, Feron FJ, Hendriksen JG, Jolles J, van Kroonenburgh MJ, Weber WE. Neuropediatrics. 2003 Apr;34(2):77-80

Smoking Thought to be a Cause: A Finnish study of 9,357 children with 8 year follow-up after birth found a 30% increased risk of hyperactivity in children whose mothers smoked during pregnancy after adjustment for sex, family structure, socioeconomic status, maternal age, and maternal alcohol use. Maternal smoking and hyperactivity in 8-year-old children. Kotimaa AJ, Moilanen I, Taanila A, Ebeling H, Smalley SL, McGough JJ, Hartikainen AL, Jarvelin MR. J Am Acad Child Adolesc Psychiatry. 2003 Jul;42(7):826-33

Smoking: Important Risk Factor: In a case-control study of 100 nonreferred Brazilian children and adolescents with ADHD-I and 100 non-ADHD controls (6-18 years old), after adjusting for confounding factors (maternal ADHD, oppositional defiant disorder, birth weight, and alcohol use during pregnancy), children whose mothers smoked >/=10 cigarettes per day during pregnancy presented a 244% higher odds ratio for ADHD-I than children who were not exposed to nicotine during pregnancy (odds ratio 3.44)(p = .002).  Smoking during pregnancy and attention-deficit/hyperactivity disorder, predominantly inattentive type: a case-control study. Schmitz M, et al. Federal University of Rio Grande do Sul, Brazil. J Am Acad Child Adoles Psychiatry 2006 Nov;45(11):1338-45.

Smoking Considered a Cause by Many Studies; Alcohol Less Clear: A review of studies from 1973-2002 found 24 studies on tobacco smoking in pregnancy, 9 on alcohol and one on caffiene. The tobacco studies generally agree in finding tobacco a factor, but the alcohol studies reach contradictory conclusions. Maternal lifestyle factors in pregnancy risk of attention deficit hyperactivity disorder and associated behaviors: review of the current evidence. Linnet KM, Dalsgaard S, Obel C, Wisborg K, Henriksen TB, Rodriguez A, Kotimaa A, Moilanen I, Thomsen PH, Olsen J, Jarvelin MR. Am J Psychiatry. 2003 Jun;160(6):1028-40.

Sugared Soft Drinks Linked to ADHD: In a cross-sectional population-based survey of 10th-grade students in Oslo, Norway (n = 5498), there was a J-shaped dose-response relationship between soft drink consumption and mental distress, conduct problems, and total mental health difficulties score; that is, adolescents who did not consume soft drinks had higher scores (indicating worse symptoms) than those who consumed soft drinks at moderate levels but lower scores than those with high consumption levels. The relationship was linear for hyperactivity. In a logistic regression model, the association between soft drink consumption and mental health problems remained significant after adjustment for behavioral, social, and food-related variables. The highest adjusted odds ratios were observed for conduct problems among boys and girls who consumed 4 or more glasses of sugar-containing soft drinks per day. Consumption of soft drinks and hyperactivity, mental distress, and conduct problems among adolescents in Oslo, Norway. Lien L, et al. University of Oslo, Norway. . Am J Publ Health 2006 Oct;96(10):1815-20.

Television Viewing: Two Studies Link to Higher Rates of ADHD in Preschoolers: In a study of preschool children, after controlling for demographic factors (i.e., age, sex, and SES), television exposure accounted for a significant proportion of the variance in teacher ratings of inattentive/hyperactive behaviors, as well as objectively measured activity level. These findings partially replicate those from a recent, highly publicized study indicating a correlation between television exposure and attention-deficit/hyperactivity disorder (ADHD)-associated behaviors. Brief Report: Television Viewing and Risk for Attention Problems in Preschool Children. Miller CJ, et al. Queens College, City University of New York. J Pediatr Psychol 2006 Sep 30.

Tooth Decay Much More Common in ADHD: In a New Zealand study of 128 children with ADHD and 128 matched controls, ADHD children had 12 times the numbers of diseased, missing and filled teeth (DMFT score) than children without the condition. This was after controlling for fluoride history, medical problems, diet, and self-reported oral hygiene. Is attention-deficit hyperactivity disorder a risk factor for dental caries?. A case-control study. Broadbent JM, Ayers KM, Thomson WM. Caries Res. 2004 Jan-Feb;38(1):29-33. Ed: It would be good to see this study replicated.  It is one huge difference. There was no difference in saliva production and more cavities were found in another study, but no figures were reported in the abstract. Clin Pediatr Dent 2005 Fall;30(1):3-7.

Tuberculous Meningitis Leads to ADHD: 21 cases in South Africa, 100% ADHD in follow-up. They were more hyperactive and unable to sustain attention, more unpopular, obsessive, compulsive and aggressive than controls. Tuberculosis meningitis and attention deficit hyperactivity disorder in children. Wait JW, Stanton L, Schoeman JF. J Trop Pediatr 2002 Oct;48(5):294-9

Velocardiofacial Syndrome an Inherited Cause: Velocardiofacial syndrome (VCFS) is a relatively common developmental neuropsychiatric syndrome caused by a 22q11 microdeletion. The most common psychiatric disorder in VCFS is ADHD, affecting 35-55% of patients. In a study of 51 VCFS individuals, 41% were diagnosed with ADHD. ADHD in the first-degree relatives of the patients with ADHD than in those without was 490% more common (OR = 5.9, P = 0.006). No differences were noted between the ADHD and non-ADHD groups in mean Obstetric Complication Scale Score, gestational age, birth weight, age at first words, walking, and achieving bowel control. The two groups also had similar IQ scores (total, verbal, and performance) and had a similar average degree of severity of facial dysmorphism and cardiac and cleft anomalies. These findings indicate that ADHD in VCFS has a genetic contribution and the patients' VCFS-related developmental factors and physical illnesses play a lesser role. Genetic, developmental, and physical factors associated with attention deficit hyperactivity disorder in patients with velocardiofacial syndrome. Gothelf D, Presburger G, et al. Schneider Children's Medical Center of Israel. Am J Med Genet B Neuropsychiatr Genet. 2004 Apr 1;126(1):116-21.

Very Low Birth Weight Risk Factor for ADHD: In a study of 55 very low-birth-weight (</=1500 gm), 54 term small for gestational age (birth weight <10th centile) and 66 term control 14-15-year-olds (birth weight >/=10th centile), the very low-birth-weight group had more psychiatric symptoms and disorders (P < 0.001), especially ADHD, high frequency of ventricular dilatation, white matter reduction, thinning of corpus callosum, and gliosis (P < 0.01 vs controls). The ADHD score was significantly associated with white matter reduction and thinning of corpus callosum in this group. The term small for gestational age group had increased prevalence of psychiatric symptoms compared with controls, but not more frequent abnormalities on MRI. Low-birth-weight adolescents: psychiatric symptoms and cerebral MRI abnormalities. Indredavik MS, et al. Norwegian University of Science and Technology, Trondheim, Norway. Pediatr Neurol. 2005 Oct;33(4):259-66.

Videogames Linked to Inattentive ADHD and Lower Grades: In a survey of 9th and 10th graders and parents (72 adolescents, 72 parents), there was a significant association between time spent playing videogames for more than one hour a day and the Youngs Internet Addiction Scale (p < 0.001), overall grade point average (p < 0.019), and the Inattention and ADHD components of the Conners Parent Rating Scale (p < 0.001 and p < 0.020, respectively). No significant association was found between body mass index (BMI), exercise, number of detentions, or the Oppositional and Hyperactivity components of CPRS and video game use. A cross-sectional analysis of video games and attention deficit hyperactivity disorder symptoms in adolescents. Chan PA, et al. Ann Gen Psychiatry 2006 Oct 24;5(1):16