Prevalence rates of comorbid psychiatric disorders and suicidal ideation are considerably lower among adolescents with AN compared with adults. An early and careful assessment, along with adequate treatment of the eating disorder, might prevent the development of severe psychiatric comorbidities.

GM and WM were strongly reduced in acute AN. The completeness of brain volume rehabilitation remained equivocal.

Deficits in set-shifting abilities have been robustly described in adult patients with anorexia nervosa (AN). These deficits are associated with behavioral traits, such as rigidity and perfectionism, and are independent of starvation. However, little is known about neurocognitive deficits in juvenile patients with AN. The brain circuits that support set shifting are not fully mature in these patients. One possibility is that neuroendocrinological changes, such as elevated cortisol levels, contributing to alterations in cognitive performance in individuals with AN. Set-shifting abilities (Visual Set-Shifting Task), cortisol levels, self-reported perfectionism and obsessive personality traits were assessed in 28 female adolescent patients with AN before (T0) and after (T1) weight rehabilitation and compared with 27 age- and IQ-matched healthy controls (CG). Compared with the CG, AN patients showed increased reaction times (RT) in shift trials (p < 0.001) and reduced error rates in both shift and non-shift trials across time points (p < 0.05). Across all subjects, perfectionism was associated with increased RTs during shift trials at T1 (r = 0.35, p < 0.05). Subjects with lower cortisol levels showed increased RTs and more errors in non-shift trials (p < 0.05). In contrast to the findings in adult patients, adolescent patients with AN did not display a marked deficit in set-shifting abilities. Instead, they demonstrated a perfectionistic cognitive style that was characterized by increased RTs in shift trials but improved accuracy. One could speculate that the shorter duration of illness and the incomplete maturation of the prefrontal cortices contribute to these findings.

The maintenance of normal body weight is disrupted in patients with anorexia nervosa (AN) for prolonged periods of time. Prior to the onset of AN, premorbid body mass index (BMI) spans the entire range from underweight to obese. After recovery, patients have reduced rates of overweight and obesity. As such, loci involved in body weight regulation may also be relevant for AN and vice versa. Our primary analysis comprised a cross-trait analysis of the 1000 single nucleotide polymorphisms (SNPs) with the lowest p-values in a genome-wide association meta-analysis (GWAMA) of AN (GCAN) for evidence of association in the largest published GWAMA for BMI (GIANT). Subsequently we performed sex-stratified analyses for these 1000 SNPs. Functional ex vivo studies on four genes ensued. Lastly, a look-up of GWAMA-derived BMI related loci was performed in the AN GWAMA. We detected significant associations (p-values < 5×10−5, Bonferroni corrected p < 0.05) for 9 SNP alleles at 3 independent loci. Interestingly, all AN susceptibility alleles were consistently associated with increased BMI. None of the genes (chr. 10: CTBP2, chr. 19: CCNE1, chr. 2: CARF and NBEAL1; the latter is a region with high linkage disequilibrium) nearest to these SNPs has previously been associated with AN or obesity. Sex-stratified analyses revealed that the strongest BMI signal originated predominantly from females (chr. 10 rs1561589; poverall: 2.47 × 10−06/pfemales: 3.45 × 10−07/pmales: 0.043). Functional ex vivo studies in mice revealed reduced hypothalamic expression of Ctbp2 and Nbeal1 after fasting. Hypothalamic expression of Ctbp2 was increased in diet induced obese (DIO) mice as compared to age-matched lean controls. We observed no evidence for associations for the look-up of BMI related loci in the AN GWAMA. A cross-trait analysis of AN and BMI loci revealed variants at three chromosomal loci with potential joint impact. The chromosome 10 locus is particularly promising given that the association with obesity was primarily driven by females. In addition, the detected altered hypothalamic expression patterns of Ctbp2 and Nbeal1 as a result of fasting and DIO implicate these genes in weight regulation.

Body mass index (BMI) is one of the most important outcome predictors in patients with anorexia nervosa (AN). A low premorbid BMI percentile calculated by the patients recalled premorbid weight and the height at first admission has been found to predict the BMI at first inpatient admission. In this study, we sought to confirm this relationship. We additionally analyze the relationship between premorbid BMI percentile and BMI percentile at discharge from the first inpatient treatment and at 1-year follow-up or alternatively if applicable upon readmission within this time period. We included 161 female patients aged 11-18 years of the multisite ANDI-trial with a DSM-IV diagnosis of AN. We used a multivariate statistical model including the independent variables age, duration of illness, duration of treatment, BMI at admission and BMI percentile at discharge. The relationship between premorbid BMI percentile and BMI at admission was solidly confirmed. In addition to premorbid BMI percentile, BMI at admission and age were significant predictors of BMI percentile at discharge. BMI percentile at discharge significantly predicted BMI percentile at 1-year follow-up. An additional analysis that merely included variables available upon referral revealed that premorbid BMI percentile predicts the 1-year follow-up BMI percentile. Further studies are required to identify the underlying biological mechanisms and to address the respective treatment strategies for AN patients with a low or high premorbid BMI percentile.