Are plasma homocysteine and methionine elevated when binging and purging behavior complicates anorexia nervosa? Evidence against the transdiagnostic theory of eating disorders

MTHFR Polymorphisms in Girls with Anorexia Nervosa: Implications on Body Weight

The development of atypical vs typical anorexia nervosa (AN) might be explained by the genetic background. We assessed the link between the subtypes of AN and the genetic polymorphisms of the thrombotic panel and the methyltetrahydrofolate reductase (MTHFR) gene. This cross-sectional pilot study recruited 48 girls with AN and 10 age-matched control girls with normal menstruation. We recorded anthropometric parameters and obtained blood samples for genotyping and hormonal assessment. Classification of AN was performed according to the DSM-V criteria. Girls with AN had 2.66 times higher odds of carrying at least one genetic polymorphism from the MTHFR panel (C677T and A1298C) compared with girls without AN (OR = 2.660, p-value = 0.041; CI 95% 1.057-6.720). The presence of atypical vs typical AN was associated independently with the presence of any of the assessed MTHFR polymorphisms (C677T, OR = 4.929, 95% CI 1.076-22.579, p-value = 0.040; A1298C, OR = 0.097, 95% CI 0.011-0.866, p-value = 0.037) in age and estrogen adjusted models. The atypical presentation of AN is mainly linked with higher prevalence of the MTHFR C677T and lower prevalence of the A1298C polymorphism.

Transdiagnostic psychiatry: a systematic review

The usefulness of current psychiatric classification, which is based on ICD/DSM categorical diagnoses, remains questionable. A promising alternative has been put forward as the "transdiagnostic" approach. This is expected to cut across existing categorical diagnoses and go beyond them, to improve the way we classify and treat mental disorders. This systematic review explores whether self-defining transdiagnostic research meets such high expectations. A multi-step Web of Science literature search was performed according to an a priori protocol, to identify all studies that used the word "transdiagnostic" in their title, up to May 5, 2018. Empirical variables which indexed core characteristics were extracted, complemented by a bibliometric and conceptual analysis. A total of 111 studies were included. Most studies were investigating interventions, followed by cognition and psychological processes, and neuroscientific topics. Their samples ranged from 15 to 91,199 (median 148) participants, with a mean age from 10 to more than 60 (median 33) years. There were several methodological inconsistencies relating to the definition of the gold standard (DSM/ICD diagnoses), of the outcome measures and of the transdiagnostic approach. The quality of the studies was generally low and only a few findings were externally replicated. The majority of studies tested transdiagnostic features cutting across different diagnoses, and only a few tested new classification systems beyond the existing diagnoses. About one fifth of the studies were not transdiagnostic at all, because they investigated symptoms and not disorders, a single disorder, or because there was no diagnostic information. The bibliometric analysis revealed that transdiagnostic research largely restricted its focus to anxiety and depressive disorders. The conceptual analysis showed that transdiagnostic research is grounded more on rediscoveries than on true innovations, and that it is affected by some conceptual biases. To date, transdiagnostic approaches have not delivered a credible paradigm shift that can impact classification and clinical care. Practical "TRANSD"iagnostic recommendations are proposed here to guide future research in this field.

Decreased whole-blood global DNA methylation is related to serum hormones in anorexia nervosa adolescents

OBJECTIVES

The one-carbon metabolism, also known as methionine-homocysteine cycle, governs the dynamics of DNA methylation, epigenetically regulating gene expression, and has been reported altered in anorexia nervosa (AN) adult patients. The aim of this study consisted in assessing whole-blood DNA methylation in adolescent AN patients, assessing its significance in relationship to clinical and hormonal variables.

METHODS

Whole-blood global DNA methylation was measured as incorporation of [(3)H]dCTP following HpaII cut in 32 adolescent females affected by restrictive type AN and compared to 13 healthy controls. Homocysteine, vitamin B12 and folate plasma levels were assessed as well as fasting plasma levels of leptin and steroid hormones. Clinical variables, including severity and associate states and traits, were assessed by means of the EDI-3, CDI and STAI-Y scales.

RESULTS

We confirm that whole-blood global DNA methylation is modestly albeit significantly reduced in AN adolescents with respect to controls, correlating with plasma leptin and steroid hormone levels. Conversely, clinical traits did not correlate with the outcome variable.

CONCLUSIONS

A better definition of the epigenetic dysregulation underlying AN pathology or vulnerability might lead to develop useful markers for diagnosis, prognostic classification and tailored therapeutic interventions in these vulnerable patients since the earliest phases of their disease.