Blood lead concentrations and attention deficit hyperactivity disorder in Korean children: a hospital-based case control study.

BACKGROUND: Because the developing brain of a child is vulnerable to environmental toxins, even very low concentration of neurotoxin can affect children's neurodevelopment. Lead is a neurotoxic heavy metal which has the harmful effect on the striatal-frontal circuit of brain. This area of the brain is known to be closely related to attention deficit hyperactivity disorder (ADHD) pathophysiology. The primary objective of the present study was to investigate whether elevated blood lead concentration is a risk factor for ADHD. The secondary objective was to examine the association between blood lead concentration and symptom severity. METHODS: We conducted a frequency-matched, hospital-based case-control study with 114 medically diagnosed ADHD cases and 114 controls. The participants were matched for age and sex. The diagnoses of ADHD were assessed with semi-structured diagnostic interviews. The participants completed the continuous performance test (CPT), and their parents completed the ADHD-rating scale (ADHD-RS). Blood lead concentrations were measured by using graphite furnace atomic absorption spectrometry featuring Zeeman background correction. RESULTS: Children with ADHD exhibited blood lead concentrations that were significantly higher than those of the controls ( 1.90 ± 086 µg/dℓ vs. 1.59 ± 0.68 µg/dℓ, p = 0.003). The log transformed total blood lead concentration was associated with a higher risk of ADHD (OR: 1.60, 95 % CI: 1.04-2.45, p < 0.05). The analysis also revealed that the children with blood lead concentrations above 2.30 µg/dℓ were at a 2.5-fold (95 % CI: 1.09-5.87, p < 0.05) greater risk of having ADHD. After adjusting for covariates, our multivariate regression models indicated that blood lead concentrations were not significantly associated with ADHD-RS or CPT profiles among the ADHD cases. CONCLUSION: Even low blood lead concentrations are a risk factor for ADHD in children. This study warrants primary prevention policies to reduce the environmental lead burden. Future studies may be required to ascertain the effects of lead on symptom severity in ADHD.

Differences in cognitive function and daily living skills between early- and late-stage schizophrenia.

OBJECTIVES: Cognitive dysfunction is a core feature of schizophrenia; deficits often manifest prior to diagnosis and persist throughout the course of the illness. This study was performed to assess the difference in cognitive function and daily living skills between the early- and late-stage schizophrenia. METHODS: Fifty-five clinically stable patients with schizophrenia were recruited (25 with < 5-year and 30 with > 5-year disease durations). We evaluated subjects' clinical states, cognitive function, and psychosocial factors. The Korean versions of MATRICS Consensus Cognitive Battery and UCSD Performance-based Skills Assessment were used for evaluating cognitive function and daily living skills. Chi-square, Wilcoxon rank sum, and t-tests were used to analyze the data. RESULTS: The two groups did not differ for most demographic variables. No significant differences between groups were found for clinical symptoms, psychosocial factors, or non-social cognitive domains. However, the early-stage group had higher social cognition domain scores than the late-stage group (p = 0.01). Early-stage patients scored significantly higher than those in the late-stage group did in the communication and comprehension/planning domains (p = 0.037 and 0.027, respectively), and total score (p = 0.003) of the Performance-based Skills Assessment. CONCLUSIONS: We observed significant differences between patients with early- and late-stage illness with regard to social cognition and performance-based skills.

Bone mineral density and osteoporosis risk in older patients with schizophrenia.

OBJECTIVE: People with schizophrenia are at a higher risk for osteoporosis. The authors investigated the prevalence of low bone density and its risk factors in older Korean patients with schizophrenia. METHOD: In cross-sectional study, 327 inpatients with schizophrenia were screened. Among them, 229 patients older than 50 years participated in this study. The control group consisted of healthy volunteers who were of similar ages (n = 125). Bone density was measured in the lumbar spine and the neck, trochanter, and ward regions of the right proximal femur by dual-energy x-ray absorptiometry. Clinical variables such as alcohol use, cigarette smoking, and fracture history were obtained. The Student t test, Pearson χ2 test, Wilcoxon rank sum test, and logistic regression analysis were used. RESULTS: The prevalence of osteoporosis was significantly higher in patients with schizophrenia compared with healthy controls (34.9% vs 18.4%, P = 0.0043). Within the schizophrenia group, female subjects had a significantly higher prevalence of osteoporosis than male subjects (48.4% vs 25.7%, P = 0.0014); however, no sex differences were identified in the healthy control group. The actual bone density and t scores in patients with schizophrenia were significantly lower in all sites than in healthy controls. Among patients with schizophrenia, smokers and alcohol abuser showed lower bone density compared with those who did not smoke or drink. The lifetime prevalence of fracture was significantly higher in patients with schizophrenia (24.0%) compared with healthy controls (5.6%; P = 0.001). CONCLUSIONS: Our results emphasize that older patients with schizophrenia are at risk for low bone density. Cigarette smoking and alcohol abuse are associated with low bone density in patients with schizophrenia.

Preliminary Investigation of Association between Methylphenidate and Serum Growth Markers in Children with Attention-Deficit/Hyperactivity Disorder: A Cross-Sectional Case-Control Study.

OBJECTIVES: It remains unclear whether methylphenidate (MPH) has yadverse effects on growth in children. This study aimed to investigate the association of MPH with serum biological markers of growth in children with attention-deficit/hyperactivity disorder (ADHD). METHODS: The present study included 103 children with ADHD (64 drug-naive children, 39 MPH-treated children) and 112 control subjects. Children with ADHD were diagnosed on the basis of a semi-structured interview. Levels of biochemical markers of growth, including insulin-like growth factor-I, thyroid stimulating hormone (TSH), free T4, calcium, phosphorus, alkaline phosphatase, vitamin D, hemoglobin, total protein, albumin, total cholesterol, and hematocrit were measured in these individuals. RESULTS: Except in case of TSH, no intergroup differences were found in the levels of the growth markers. The levels of TSH were found to be lower in the MPH-treated boys with ADHD than in the drug-naive and control groups (p < 0.05), although the levels of TSH in all the groups were within normal limits. CONCLUSION: In this cross-sectional study, no significant association was found between MPH and growth markers. This calls for the need to carry out prospective longitudinal research studies in the future that investigate the effect of MPH on the growth trajectory in children.

Effect of DA-9701 on the Normal Motility and Clonidine-induced Hypomotility of the Gastric Antrum in Rats.

BACKGROUND/AIMS: DA-9701 is a novel prokinetic agent. In the present study, we investigated the effect of DA-9701 on the motility of the gastric antrum in the normal and clonidine-induced hypomotility in an in vivo animal model. METHODS: A strain gauge force transducer was sutured on the gastric antrum to measure the contractile activity in rats. A total of 28 rats were subclassified into the 4 groups: (1) the placebo group, (2) the DA-9701 group, (3) the placebo group in the clonidine-pretreated rats, and (4) the DA-9701 group in the clonidine-pretreated rats. After the basal recording, either placebo (3% [w/v] hydroxypropylmethyl cellulose) or DA-9701 was administered. Contractile signals were measured after the administration and after a meal. In the clonidinepretreated rats, either placebo or DA-9701 was administered. Contractile signals were measured after the administration and after a meal. RESULTS: Oral administration of DA-9701 did not significantly alter the motility index of the gastric antrum in the preprandial and postprandial periods, compared with the placebo group. The administration of clonidine decreased the motility index of the gastric antrum in the preprandial and postprandial periods, compared with the administration of placebo. This reduction of the antral motility by the administration of clonidine was not observed in the clonidine-pretreated DA-9701 group. The percentage of the motility index in the postprandial period was significantly greater in the clonidine-pretreated DA-9701 group, compared with the clonidine-pretreated placebo group. CONCLUSIONS: DA-9701 improves the hypomotility of the gastric antrum induced by clonidine, suggesting its gastroprokinetic effect in the pathologic condition.

The Relationship between Language Ability and Cognitive Function in Patients with Schizophrenia.

OBJECTIVE: Cognitive dysfunction is common in people with schizophrenia, and language disability is one of the most notable cognitive deficits. This study assessed the use and comprehension ability of the Korean language in patients with schizophrenia and the correlations between language ability and cognitive function. METHODS: Eighty-six patients with schizophrenia and a group of 29 healthy controls were recruited. We assessed both clinical symptoms and cognitive functions including Korean language ability. For clinical symptoms, the Positive and Negative Syndrome Scale, Clinical Global Impression-Schizophrenia Scale, and Social and Occupational Functioning Assessment Scale were used. For the Korean language ability assessment, a portion of the Korean Broadcasting System (KBS) Korean Language Test was used. The Short-form of Korean-Wechsler Adult Intelligence Scale, the Korean version of the University of California San Diego (UCSD) Performance-based Skills Assessment (K-UPSA), and the Wisconsin Card Sorting Test (WCST) were used to assess cognitive functions. RESULTS: Schizophrenic patients had significantly lower scores in the language and cognitive function tests both in the total and subscale scores. Various clinical scores had negative correlations with reading comprehension ability of the KBS Korean Language Test. The WCST and a part of the K-UPSA had positive correlations with multiple domains of the language test. CONCLUSION: A significant difference was found between schizophrenic patients and controls in language ability. Correlations between Korean language ability and several clinical symptoms and cognitive functions were demonstrated in patients with schizophrenia. Tests of cognitive function had positive correlations with different aspects of language ability.

Visual perception of ADHD children with sensory processing disorder.

OBJECTIVE: The aim of the present study was to investigate the visual perception difference between ADHD children with and without sensory processing disorder, and the relationship between sensory processing and visual perception of the children with ADHD. METHODS: Participants were 47 outpatients, aged 6-8 years, diagnosed with ADHD. After excluding those who met exclusion criteria, 38 subjects were clustered into two groups, ADHD children with and without sensory processing disorder (SPD), using SSP reported by their parents, then subjects completed K-DTVP-2. Spearman correlation analysis was run to determine the relationship between sensory processing and visual perception, and Mann-Whitney-U test was conducted to compare the K-DTVP-2 score of two groups respectively. RESULTS: The ADHD children with SPD performed inferiorly to ADHD children without SPD in the on 3 quotients of K-DTVP-2. The GVP of K-DTVP-2 score was related to Movement Sensitivity section (r=0.368(*)) and Low Energy/Weak section of SSP (r=0.369*). CONCLUSION: The result of the present study suggests that among children with ADHD, the visual perception is lower in those children with co-morbid SPD. Also, visual perception may be related to sensory processing, especially in the reactions of vestibular and proprioceptive senses. Regarding academic performance, it is necessary to consider how sensory processing issues affect visual perception in children with ADHD.

Dietary patterns in children with attention deficit/hyperactivity disorder (ADHD).

The role of diet in the behavior of children has been controversial, but the association of several nutritional factors with childhood behavioral disorders has been continually suggested. We conducted a case-control study to identify dietary patterns associated with attention deficit hyperactivity disorder (ADHD). The study included 192 elementary school students aged seven to 12 years. Three non-consecutive 24-h recall (HR) interviews were employed to assess dietary intake, and 32 predefined food groups were considered in a principal components analysis (PCA). PCA identified four major dietary patterns: the "traditional" pattern, the "seaweed-egg" pattern, the "traditional-healthy" pattern, and the "snack" pattern. The traditional-healthy pattern is characterized by a diet low in fat and high in carbohydrates as well as high intakes of fatty acids and minerals. The multivariate-adjusted odds ratio (OR) of ADHD for the highest tertile of the traditional-healthy pattern in comparison with the lowest tertile was 0.31 (95% CI: 0.12-0.79). The score of the snack pattern was positively associated with the risk of ADHD, but a significant association was observed only in the second tertile. A significant association between ADHD and the dietary pattern score was not found for the other two dietary patterns. In conclusion, the traditional-healthy dietary pattern was associated with lower odds having ADHD.

Adjunctive varenicline treatment with antipsychotic medications for cognitive impairments in people with schizophrenia: a randomized double-blind placebo-controlled trial.

The aim of this study is to examine the effects of treatment with varenicline, a partial agonist at the α4ß2 and full agonist at the α7 nicotine acetylcholine receptor, on cognitive impairments in people with schizophrenia. In all, 120 clinically stable people with schizophrenia participated in randomized, double-blind, placebo-controlled 8-week trial. Antipsychotic and concomitant medication doses remained fixed throughout the study. Varenicline was titrated up to 1 mg twice daily for weeks 2-8. Neuropsychological, clinical, and safety assessments were administered at baseline and weeks 1, 2, 4, and 8. In the primary analyses of neurocognitive differences at week 8, no varenicline-placebo differences were significant. In secondary longitudinal analyses, varenicline improved compared with placebo on the Digital Symbol Substitution Test (p=0.013) and the Wisconsin Card Sorting Test non-perseverative errors (p=0.043). Some treatment effects were different between smokers and non-smokers. In smokers, Continuous Performance Test hit reaction time (p=0.008) and Stroop Interference (p=0.004) were reduced for varenicline compared with placebo, while there were no treatment differences in non-smokers. No significant treatment main effects or interactions were noted for total scores on the Positive and Negative Syndrome Scale or the Scale for the Assessment for Negative Symptoms. Our findings suggest beneficial effects of adjunctive varenicline treatment with antipsychotics for some cognitive impairments in people with schizophrenia. In some cases, effects of treatment varied between smokers and non-smokers. Further study is required to assess the functional significance of these changes.