Genetic differences between bipolar disorder subtypes: A systematic review focused in bipolar disorder type II.

BACKGROUND: The identification of bipolar disorder (BD) type II patients has both treatment and prognostic implications. Better understanding of its underlying genetics may yield useful diagnostic tools. METHODS: A systematic review on BDII genetics was done using articles published in 2009-2019, following PRISMA recommendations. RESULTS: The most studied polymorphism was BDNF Val66Met with several gene-gene interactions within the dopaminergic system. Associations were reported within the monoaminergic systems (DRD3, ADH1B and SLC6A4), calcium (CACNB2 and CACNG2) and cAMP (PDE1DA, PDE4B and DISC1) signal transduction pathways and the immune system (TNFα, IFNδ and IL-10). Chromosomes 2, 3 and 10 were associated with BDII and polygenic risk scores distinguished between BD subtypes and with major depressive disorder. CONCLUSIONS: Research on BDII stems from BDI findings, however with a stronger contribution of gene-gene interactions and low-effect alleles on known neuroplasticity and monoaminergic system genes. Genome studies point to transdiagnostic backgrounds, with wider associations across bipolar spectrum disorders. Findings able to accurately differentiate BDII remain elusive, dependent on better phenotypic characterization and new research methods.

A coin crisis: a case report of pica with minireview.

BACKGROUND: Pica is defined as a feeding and eating disorder where there is consumption of nonnutritive substances not consistent with cultural practices or social norms. Its aetiology is still unknown, as its prevalence and optimal treatment, which seem to vary with patients' characteristics and the specific behaviours involved. OBJECTIVES: The authors present a case report of pica treated with copper supplementation, with further diagnostic and treatment considerations. METHODS: Clinical records and interviews were used. A review was conducted using PubMed database. RESULTS: A 59-year-old patient, diagnosed with paranoid schizophrenia, presented with sideroblastic anaemia secondary to zinc-induced copper deficiency in the context of pica. These behaviours ceased with copper supplementation. After 2-year remission, the patient was discontinued on oral copper. One week after, pica behaviours reoccurred, with further remission with renewed copper treatment. Based on temporal relationship, we propose that there might be an association between copper supplementation and pica, not related to its plasma levels. CONCLUSIONS: As far as we know, this is the first case report in the literature with such a long-term follow-up of pica treatment. Our findings challenge the cause-effect relation between micronutrient deficiency and pica and prompts further research in the non-adaptive theories of this poorly understood clinical entity.