[Show abstract][Hide abstract] ABSTRACT: Dopamine D3 receptor-mediated pathways are involved in the mechanism of addiction, and genetic factors play a role in the vulnerability to heroin dependence. The aim of this study was to examine whether the corresponding gene, DRD3, is associated with the development of heroin dependence and specific personality traits in HD patients. Eight polymorphisms in DRD3 were analyzed in 1067 unrelated Han Chinese subjects (566 heroin dependence patients and 501 controls). All participants were screened using the same assessment tool and all patients met the criteria for heroin dependence. A Tridimensional Personality Questionnaire was used to assess personality traits in 276 heroin dependence patients. In addition, heroin dependence patients were divided into 4 clinical subgroups based on age-of-onset and family history of substance abuse, to reduce the clinical heterogeneity. The rs6280 and rs9825563 variants showed association with the development of early-onset heroin dependence. The GTA haplotype frequency in the block (rs324029, rs6280, rs9825563) was significantly associated with early-onset heroin dependence (p=0.003). However, these significant associations were weaker after Bonferroni's correction. In addition, these DRD3 polymorphisms did not influence novelty seeking and harm avoidance scores in HD patients. DRD3 is possibly a genetic factor in the development of early-onset heroin dependence, but is not associated with specific personality traits in these patients among the Han Chinese population.
Progress in Neuro-Psychopharmacology and Biological Psychiatry 01/2014; · 3.55 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Objective Comorbid personality pathologies may affect the outcome of patients with major depression (MD). The dopamine transporter gene DAT1 (SLC6A3) has been suggested to play a role in both depression and specific personality traits. The aim of this study was to assess five polymorphisms of the DAT1 gene (rs2550948, rs2975226, rs6347, rs27072, and 3′-VNTR) to determine whether this gene influences personality traits in patients with MD or its subgroups.Methods The DAT1 polymorphisms were analysed in 463 unrelated Han Chinese MD patients. The personality traits, novelty seeking (NS), and harm avoidance (HA), were examined using the Tridimensional Personality Questionnaire. The patients were also divided into four clinical subgroups on the basis of differences in their sex (male or female) and age at disease onset (early or late).Results There was no association between the DAT1 gene and either NS or HA in the total MD sample or in the sex-based subgroups. However, early-onset MD patients with the G/G genotype of rs2550948 and the T/T genotype of rs2975226 had lower NS scores than did patients with the other genotypes (p
corrected = 0.05 for rs2550948 and p
corrected = 0.005 for rs2975226).Conclusion Our study suggests that DAT1 promoter variants possibly influence specific personality traits in the early-onset subgroup of depressed patients in the Han Chinese population. Further prospective cohort studies are required to verify our preliminary finding and to confirm the effects of personality susceptibility on long-term disease outcomes.
[Show abstract][Hide abstract] ABSTRACT: Major depression is a complex psychiatric disorder involving multiple factors, including genetic and personality components. This study used 17 polymorphisms of dopamine transporter gene (DAT1) to explore whether this gene is associated with major depression and whether it influences personality traits in patients with major depression. The DAT1 polymorphisms were analyzed in 1017 unrelated individuals and 459 patients were eligible to assess personality traits. We found a borderline association between controls and total major depression and between major depression with family history versus controls; however, these differences were obscured after correction for multiple testing. Furthermore, the DAT1 polymorphisms were not associated either with major depression in haplotype analysis or with personality traits. Despite the fact that several association tendencies were found between DAT1 and major depression, we did not confirm a major role for DAT1 in the susceptibility to major depression. In addition, DAT1 does not seem to affect personality traits observed in patients with major depression.
Pharmacogenetics and Genomics 02/2011; 21(2):94-7. · 3.61 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Adjunctive use of methylphenidate, a central stimulant, has been considered as a potential therapeutic choice for patients with refractory unipolar depression, geriatric depression, bipolar depression, and depression secondary to a medical illness. We present a case of psychotic unipolar depression in which the patient responded significantly to the adjunctive use of methylphenidate. A 45-year-old woman had melancholic depressive symptoms and mood incongruent psychotic features during her second episode of unipolar depression. She attempted suicide by hanging herself and was forcibly hospitalized. She was initially treated with venlafaxine (262.5 mg/d), olanzapine (20 mg/d), and benzodiazepines. However, she responded unsatisfactorily to the combination treatment. Because her family refused electroconvulsive treatment, we added methylphenidate to her medications for adjunctive use. The dose of methylphenidate was started at a dose of 5 mg/d. It was not until the patient received 30 mg/d of methylphenidate that her persistent psychosis and severe depression were substantially improved. She tolerated her medications well and did not report any side effects. She was discharged in a stable condition 2 weeks after the adjunctive use of methylphenidate. The patient's methylphenidate was gradually tapered and finally discontinued. To date, she remains well and is regularly followed up at our outpatient clinic. Our case suggests that adjunctive use of methylphenidate can be a therapeutic option in treating some patients with psychotic unipolar depression who do not adequately respond to the combination treatment of an antidepressant and an atypical antipsychotic. Further controlled studies are warranted to verify this.