ABSTRACT
A significant overlap between childhood mood disorders and many aspects of attention deficit hyperactivity disorder (ADHD) has been established. High rates of co-occurrence, familial aggregation, and more severe clinical manifestations of the illnesses when they are comorbid suggest that common genetic and environmental factors may contribute to the development of both disorders. Research on the co-occurrence of childhood ADHD and mood disorders in childhood has been conducted. We retrospectively investigated childhood ADHD features in adults with mood disorders. Childhood ADHD features were measured with the Korean version of the Wender Utah Rating Scale (WURS). The sample consisted of 1305 subjects: 108 subjects were diagnosed with bipolar disorder type I, 41 with bipolar disorder type II, 101 with major depressive disorder, and 1055 served as normal controls. We compared total WURS scores as well as scores on 3 factors (impulsivity, inattention, and mood instability and anxiety) among the 4 different diagnostic groups. The 4 groups differed significantly from one another on all scores. The group with bipolar disorder type II obtained the highest total scores on the WURS. The impulsivity and inattention associated with childhood ADHD were more significantly related to bipolar disorder type II than with bipolar disorder type I. The mood instability and anxiety associated with childhood ADHD seem to be significantly related to major depressive disorder in adulthood. In conclusion, multifactorial childhood ADHD features were associated with mood disorders of adulthood.
Subject(s)
Attention Deficit Disorder with Hyperactivity/psychology , Mood Disorders/psychology , Adult , Attention Deficit Disorder with Hyperactivity/diagnosis , Attention Deficit Disorder with Hyperactivity/epidemiology , Bipolar Disorder/diagnosis , Bipolar Disorder/epidemiology , Bipolar Disorder/psychology , Comorbidity , Depressive Disorder, Major/diagnosis , Depressive Disorder, Major/epidemiology , Depressive Disorder, Major/psychology , Female , Humans , Male , Middle Aged , Mood Disorders/diagnosis , Mood Disorders/epidemiology , Psychiatric Status Rating Scales , Republic of Korea/epidemiology , Retrospective StudiesABSTRACT
The dual-specificity phosphatase 6 (DUSP6) gene resides at chromosome location 12q22-23, which is one of the candidate loci for susceptibility to bipolar disorder and which encodes a phosphatase selective for extracellular signal-regulated kinase (ERK). Previously, we reported a positive association between the functional Leu114Val polymorphism (rs2279574) in DUSP6 and bipolar disorder. Given that the association between DUSP6 and the reported down-regulation of DUSP6 transcript in bipolar postmortem brains were sex-dimorphic, showing significance in women but not men, we performed two independent analyses in homogenous samples of male and female Korean patients with bipolar disorder or schizophrenia using samples enlarged from our previous report. Among the examined DUSP6 SNPs, five (rs769700, rs704076, rs770087, rs808820, and rs2279574) showed positive allelic associations, with the frequency of minor alleles (C, T, G, G, and G) in each SNP significantly increased in women with BD. Consequently, the "C-T-G-G-G" haplotype was significantly over-represented (P=0.016; OR=3.242), whereas the "T-G-T-A-T" haplotype was significantly under-represented (P=0.014; OR=0.697). We found no significant associations with DUSP6 SNPs in men with bipolar disorder or schizophrenia. We also investigated the functions of the functional SNPs' positive associations and found that Leu114Val (rs2279574; T/G) and Ser144Ala (rs770087; T/G) mutations in DUSP6 proteins reduced lithium-induced ERK1/2 phosphorylation in vitro, implicating the dominant active functions. Thus, DUSP6 may not only play important roles in the pathogenesis of bipolar disorder, particularly in women, but also affect the therapeutic response to lithium through modulating lithium's effects on intracellular signaling.
Subject(s)
Bipolar Disorder/enzymology , Bipolar Disorder/genetics , Dual Specificity Phosphatase 6/genetics , Genetic Association Studies/methods , MAP Kinase Signaling System/physiology , Polymorphism, Single Nucleotide/genetics , Adult , Alleles , Enzyme Activation/genetics , Enzyme Activation/physiology , Female , HeLa Cells , Humans , MAP Kinase Signaling System/genetics , Male , Middle Aged , Young AdultABSTRACT
The early growth response gene 2 (EGR2) is located at chromosome 10q21, one of the susceptibility loci in bipolar disorder (BD). EGR2 is involved in cognitive function, myelination, and signal transduction related to neuregulin-ErbB receptor, Bcl-2 family proteins, and brain-derived neurotrophic factor. This study investigated the genetic association of the EGR2 gene with BD and schizophrenia (SPR) in Korea. In 946 subjects (350 healthy controls, 352 patients with BD, and 244 with SPR), nine single nucleotide polymorphisms (SNPs) in the EGR2 gene region were genotyped. Five SNPs showed nominally significant allelic associations with BD (rs2295814, rs61865882, rs10995315, rs2297488, and rs2297489), and the positive associations of all except rs2297488 remained significant after multiple testing correction. Linkage disequilibrium structure analysis revealed two haplotype blocks. Among the common identified haplotypes (frequency > 5%), 'T-G-A-C-T (block 1)' and 'A-A-G-C (block 2)' haplotypes were over-represented, while 'C-G-G-T-T (block 1)' haplotype was under-represented in BD. In contrast, no significant associations were found with SPR. Although an extended analysis with a larger sample size or independent replication is required, these findings suggest a genetic association of EGR2 with BD. Combined with a plausible biological function of EGR2, the EGR2 gene is a possible susceptibility gene in BD.