Psychiatry research
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The need for rapid acting antidepressants is widely recognised. There has been much interest in glutamate mechanisms in major depressive disorder (MDD) as a promising target for the development of new antidepressants. A single intravenous infusion of ketamine, a N-methyl-d-aspartate (NMDA) receptor antagonist anaesthetic agent, can alleviate depressive symptoms in patients within hours of administration. ⋯ The article reviews the effect of current antidepressants on NMDA and examines the efficacy and mechanism of ketamine. Response to ketamine is also discussed and comparison with other glutamate drugs including lamotrigine, amantadine, riluzole, memantine, traxoprodil, GLYX-13, MK-0657, RO4917523, AZD2066 and Coluracetam. Future studies need to link the rapid antidepressant effects seen with ketamine to inflammatory theories in MDD.
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Psychiatry research · Jan 2015
Alterations of GABA and glutamate-glutamine levels in premenstrual dysphoric disorder: a 3T proton magnetic resonance spectroscopy study.
Increasing evidence has suggested that the GABAergic neurotransmitter system is involved in the pathogenesis of premenstrual dysphoric disorder (PMDD). We used proton magnetic resonance spectroscopy ((1)H MRS) to investigate whether PMDD is associated with alterations in brain GABA levels. Levels of glutamate-glutamine (Glx) were also explored. ⋯ Water-scaled GABA+ concentrations and GABA+/tCr ratios were significantly lower in both the ACC/mPFC and ltBG regions of PMDD women than in healthy controls. Glx/tCr ratios were significantly higher in the ACC/mPFC region of PMDD women than healthy controls. Our preliminary findings provide the first report of abnormal levels of GABA+ and Glx in mood-related brain regions of women with PMDD, indicating that dysregulation of the amino acid neurotransmitter system may be an important neurobiological mechanism in the pathogenesis of PMDD.
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Psychiatry research · Jan 2015
Multi-dimensional correlates of Internet addiction symptoms in adolescents with attention-deficit/hyperactivity disorder.
This study examined the associations of the severity of Internet addiction symptoms with reinforcement sensitivity, family factors, Internet activities, and attention-deficit/hyperactivity disorder (ADHD) symptoms among adolescents in Taiwan diagnosed with ADHD. A total of 287 adolescents diagnosed with ADHD and aged between 11 and 18 years participated in this study. Their levels of Internet addiction symptoms, ADHD symptoms, reinforcement sensitivity, family factors, and various Internet activities in which the participants engaged were assessed. ⋯ Meanwhile, low paternal occupational SES, low BAS drive, and online gaming were also significantly associated with severe Internet addiction symptoms. Multiple factors are significantly associated with the severity of Internet addiction symptoms among adolescents with ADHD. Clinicians, educational professionals, and parents of adolescents with ADHD should monitor the Internet use of adolescents who exhibit the factors identified in this study.