Bipolar spectrum disorder: What evidence for pharmacological treatment? A systematic review

Bipolar disorder in the International Classification of Diseases-Eleventh version: A review of the changes, their basis, and usefulness

The World Health Organization’s 11^th revision of the International Classification of Diseases (ICD-11) including the chapter on mental disorders has come into effect this year. This review focuses on the “Bipolar or Related Disorders” section of the ICD-11 draft. It describes the benchmarks for the new version, particularly the foremost principle of clinical utility. The alterations made to the diagnosis of bipolar disorder (BD) are evaluated on their scientific basis and clinical utility. The change in the diagnostic requirements for manic and hypomanic episodes has been much debated. Whether the current criteria have achieved an optimum balance between sensitivity and specificity is still not clear. The ICD-11 definition of depressive episodes is substantially different, but the lack of empirical support for the changes has meant that the reliability and utility of bipolar depression are relatively low. Unlike the Diagnostic and Statistical Manual of Mental Disorders, 5^th edition (DSM-5), the ICD-11 has retained the category of mixed episodes. Although the concept of mixed episodes in the ICD-11 is not perfect, it appears to be more inclusive than the DSM-5 approach. Additionally, there are some uncertainties about the guidelines for the subtypes of BD and cyclothymic disorder. The initial results on the reliability and clinical utility of BD are promising, but the newly created diagnostic categories also appear to have some limitations. Although further improvement and research are needed, the focus should now be on facing the challenges of implementation, dissemination, and education and training in the use of these guidelines.

Deficient LEF1 expression is associated with lithium resistance and hyperexcitability in neurons derived from bipolar disorder patients

Bipolar disorder (BD) is a psychiatric condition characterized by depressive and manic episodes that affect 2% of the world population. The first-line long-term treatment for mood stabilization is lithium (Li). Induced pluripotent stem cell modeling of BD using hippocampal dentate gyrus-like neurons derived from Li-responsive (LR) and Li-non-responsive (NR) patients previously showed neuronal hyperexcitability. Li treatment reversed hyperexcitability only on the LR neurons. In this study we searched for specific targets of Li resistance in NR neurons and found that the activity of Wnt/β-catenin signaling pathway was severely affected, with a significant decrease in expression of LEF1. Li targets the Wnt/β-catenin signaling pathway by inhibiting GSK-3β and releasing β-catenin that forms a nuclear complex with TCF/LEF1, activating the Wnt/β-catenin transcription program. Therefore, we propose that downregulation of LEF1 may account for Li resistance in NR neurons. Our results show that valproic acid (VPA), a drug used to treat NR patients that also acts downstream of GSK-3β, upregulated LEF1 and Wnt/β-catenin gene targets, increased transcriptional activity of complex β-catenin/TCF/LEF1, and reduced excitability in NR neurons. In addition, decreasing LEF1 expression in control neurons using shLEF1 caused hyperexcitability, confirming that the impact of VPA on excitability in NR neurons was connected to changes in LEF1 and in the Wnt/β-catenin pathway. Our results suggest that LEF1 may be a useful target for the discovery of new drugs for BD treatment.

Effects of repetitive transcranial magnetic stimulation on suicidal behavior: A systematic review

The efficacy and tolerability of repetitive transcranial magnetic stimulation (rTMS) in major depression is well-known and documented by existing studies. However, whether rTMS may be effective on suicidal behavior is unclear and needs to be further investigated. This systematic review is aimed to investigate the available literature about the effects of rTMS on suicidal behavior and provide a comprehensive overview of the available evidence. A systematic search regarding the association between rTMS and suicidal behavior was carried out. All relevant articles concerning this association were comprehensively searched on PubMed, Scopus, Science Direct, and PsycInfo databases. After a careful search, 16 articles (7 sham-controlled studies, 5 uncontrolled studies, 4 case-series) met inclusion criteria and were selected in this systematic review. Overall, the left dorsolateral prefrontal cortex (DLPFC) was identified as the most frequent stimulation target by most studies. Unfortunately, actually it is not clear whether suicidal behavior reduction may be mediated, at least in some cases, by depression attenuation. While some methodological heterogeneity was found in terms of stimulation parameters (e.g., frequency, number of sessions, intensity of stimulation), most of the analyzed articles showed that rTMS is a safe, applicable, well tolerated and reproducible method in treating suicidal behavior. The most effective treatment seems to be the bilateral rTMS as well as the combination with antidepressants. Further longitudinal studies are required in order to replicate the mentioned study results.