Suggestive evidence for linkage of ADHD features in bipolar disorder to chromosome 10p14

Effectiveness of methylphenidate and PUFA for the treatment of patients with ADHD: A double-blinded randomized clinical trial

BACKGROUND

In some children with ADHD, sub-optimal levels of various nutrients including PUFA especially omega-3 has been observed, and contradictory reports exist on the results of studies conducted on the positive therapeutic effects of PUFA in patients with ADHD.

OBJECTIVE

The aim of this study was to investigate the effectiveness of methylphenidate and PUFA on treatment of patients with ADHD in Zahedan, Iran.

METHODS

In this clinical trial, 40 children between 6 and 12 years of age with ADHD were investigated in Zahedan in 2014. Patients were randomly divided into two groups of methylphenidate plus PUFA and methylphenidate plus placebo. ADHD rating scale was filled before and after the study for patients of both groups. Finally, data were analyzed using SPSS18, paired-samples t-test and chi-square.

RESULTS

Mean age of patients was 2.9±1.8 years. Thirty-three children (82.5%) were boys and seven children (17.5%) were girls. Mean severity of signs in the group under methylphenidate plus PUFA treatment was 39.9±4.9 before treatment and 20.1±6.0 after 8 weeks of treatment (p<0.001). Mean severity of signs in the group under methylphenidate plus placebo treatment was 41.2±2.7 before treatment and 26.1±9.0 after 8 weeks of treatment (p<0.001). Mean reduction in the severity of symptoms in the group under methylphenidate therapy was 19.7±5.9 and in PUFA and placebo group it was 15.1±9.3 (p<0.067). Response to treatment (a reduction of at least 25% in the signs) in the group taking methylphenidate plus PUFA was 90% (18 patients) and in methylphenidate plus placebo group, it was 60% (12 patients) (p=0.028).

CONCLUSION

This study shows that PUFA is an efficient nutrient to treat ADHD and it can be used to treat patients. However, definitive conclusion requires repeating the study with a larger sample and longer study period.

TRIAL REGISTRATION

The trial was registered at the Iranian Registry of Clinical Trials (http://www.irct.ir) with the Irct ID: IRCT2015092724209N2.

FUNDING

The authors received no financial support for the research, authorship, and/or publication of this article.

Association between the 5-HTTLPR Genotype and Childhood Characteristics in Mood Disorders

Objective

The features of childhood attention deficit hyperactivity disorder (ADHD) are significantly associated with adult mood disorders. Some genetic factors may be common to both ADHD and mood disorders underlie the association between these two phenotypes. The present study aimed to determine whether a genetic role may be played by the serotonin transporter-linked polymorphic region (5-HTTLPR) in the childhood ADHD features of adult patients with mood disorders.

Methods

The present study included 232 patients with major depressive disorder (MDD), 154 patients with bipolar disorder (BPD), and 1,288 normal controls. Childhood ADHD features were assessed with the Korean version of the Wender Utah Rating Scale (WURS-K). The total score and the scores of three factors (impulsivity, inattention, and mood instability) from the WURS-K were analyzed to determine whether they were associated with the 5-HTTLPR genotype.

Results

In the BPD type II group, the 5-HTTLPR genotype was significantly associated with the total score (p=0.029) and the impulsivity factor (p=0.004) on the WURS-K. However, the inattention and mood instability factors were not associated with the 5-HTTLPR genotype. BPD type I, MDD and normal control groups did not exhibit any significant associations between the WURS-K scores and the 5-HTTLPR genotype.

Conclusion

The findings suggest that the 5-HTTLPR genotype may play a role in the impulsivity component of childhood ADHD in patients with BPD type II. Because of a small sample size and a single candidate gene, further studies investigating other candidate genes using a larger sample are warranted to determine any common genetic links.

T2D and Depression Risk Gene Proteasome Modulator 9 is Linked to Insomnia

Insomnia increases type-2 diabetes (T2D) risk. The 12q24 locus is linked to T2D, depression, bipolar disorder and anxiety. At the 12q24 locus, the Proteasome-Modulator 9 (PSMD9) single nucleotide polymorphisms (SNPs) rs74421874 [intervening sequence (IVS) 3+nt460-G>A], rs3825172 (IVS3+nt437-C>T) and rs14259 (E197G-A>G) are linked to: T2D, depression, anxiety, maturity-onset-diabetes-of the young 3/MODY3, obesity, waist circumference, hypertension, hypercholesterolemia, T2D-macrovascular disease, T2D-microvascular disease, T2D-neuropathy, T2D-carpal-tunnel syndrome, T2D-nephropathy, T2D-retinopathy and non-diabetic retinopathy. PSMD9 SNP rs1043307/rs14259 (E197G-A>G) plays a role in anti-depressant therapy response, depression and schizophrenia. We aimed at determining PSMD9 rs74421874/rs3825172/rs14259 SNPs potential linkage to primary insomnia and sleep hours in T2D families. We recruited 200 Italian T2D families phenotyping them for primary insomnia and sleep hours per night. PSMD9-T2D-risk SNPs rs74421874/rs3825172 and rs1043307/rs14259 were tested for linkage with insomnia and sleep hours. Non-parametric-linkage analysis, linkage-disequilibrium-model analysis, single-SNP analysis, cluster-based-parametric analysis, quantitative-trait and variant-component analysis were performed using Merlin software. To validate data, 1000 replicates were executed for the significant non-parametric data. PSMD9 rs74421874 (IVS3+nt460-G>A), rs3825172 (IVS3+nt437-C>T) and rs1043307/rs14259 (E197G-A>G) SNPs are linked to insomnia in our Italian families.

Association of dopamine transporter gene variants with childhood ADHD features in bipolar disorder

Bipolar disorder (BD) and attention deficit hyperactivity disorder (ADHD) exhibit remarkably high rates of comorbidity, as well as patterns of familial co-segregation. Epidemiological data suggests that these disorders either share a common genetic architecture or that ADHD features in BD may represent an etiologically distinct subtype. We previously used the Wender Utah Rating Scale (WURS) to assess ADHD features in BD families and identified three heritable factors relating to impulsivity, mood instability, and inattention. Linkage analysis revealed a LOD score of 1.33 for the inattention factor on 5p15.3 near the dopamine transporter gene (DAT1), which has been associated with both BD and ADHD. Pharmacological evidence also suggests a role for DAT in both disorders. We have now evaluated the association of ten DAT1 variants for the WURS total score and factors in an overlapping sample of 87 BD families. Significant associations for three SNPs were observed across the WURS measures, notably for a SNP in intron 8 with the WURS total score (P = 0.007) and for variants in introns 9 and 13 with mood instability (P = 0.009 and 0.004, respectively). Analysis of an independent sample of 52 BD cases and 46 healthy controls further supported association of the intron 8 variant with mood instability (P = 0.005), and a combined analysis confirmed the associations of this SNP with WURS total score. Impulsivity and mood instability (P = 0.002, 0.007, and 8 × 10(-4), respectively). These data suggest that variants within DAT1 may predispose to a subtype of BD characterized by early prodromal features that include attentional deficits.

Genome-wide significant association between a 'negative mood delusions' dimension in bipolar disorder and genetic variation on chromosome 3q26.1

Research suggests that clinical symptom dimensions may be more useful in delineating the genetics of bipolar disorder (BD) than standard diagnostic models. To date, no study has applied this concept to data from genome-wide association studies (GWAS). We performed a GWAS of factor dimensions in 927 clinically well-characterized BD patients of German ancestry. Rs9875793, which is located in an intergenic region of 3q26.1 and in the vicinity of the solute carrier family 2 (facilitated glucose transporter), member 2 gene (SLC2A2), was significantly associated with the factor analysis-derived dimension 'negative mood delusions' (n=927; P=4.65 × 10(-8), odds ratio (OR)=2.66). This dimension was comprised of the symptoms delusions of poverty, delusions of guilt and nihilistic delusions. In case-control analyses, significant association with the G allele of rs9875793 was only observed in the subgroup of BD patients who displayed symptoms of 'negative mood delusions' (allelic χ(2) model: P(G)=0.0001, OR=1.92; item present, n=89). Further support for the hypothesis that rs9875793 is associated with BD in patients displaying 'negative mood delusions' symptom, such as delusions of guilt, was obtained from an European American sample (GAIN/TGEN), which included 1247 BD patients and 1434 controls (P(EA)=0.028, OR=1.27).