Background Anorexia nervosa (AN) is a severe mental illness, with an unknown etiology. could be related to predisposing factors of the illness, or whether they are regions that are more 476474-11-0 supplier vulnerable to starvation, malnutrition or associated processes in AN. Electronic supplementary material The online version of this article (doi:10.1186/s12888-016-1126-9) contains supplementary material, which is available to authorized users. Keywords: Anorexia Hsh155 nervosa, Neuroimaging, Brain volumes, Cortical thickness, MRI, Adolescence Background Anorexia nervosa (AN) is a severe psychiatric illness characterized by extreme underweight, an intense fear of gaining weight, and a disturbance in the way ones body weight or shape is experienced . An increasing number of neuroimaging studies have investigated brain structure in patients with AN, but the majority of these studies has included adult samples. As the onset of AN usually is during adolescence , adults with AN will on average have a longer duration of illness than younger individuals. Due to starvation and malnutrition, it is likely that having an eating disorder over a long time period will affect the brain. To identify regions susceptible to short term starvation and malnutrition effects, it is of particular interest to investigate young people with AN. Previous studies have typically reported reduced brain volumes in individuals with AN compared to healthy controls. Results from a recent meta-analysis showed that patients with AN had a significant decrease in total grey matter volume (GMV), white matter volume (WMV) as well as significantly increased cerebrospinal fluid (CSF) volumes . In addition to reduced gross brain volumes and increased CSF in individuals with AN, regional grey matter volume differences between patients and controls have also been demonstrated. Findings are inconsistent, as the reported anatomical locations and extent of these differences are highly variable. The aforementioned meta-analysis reported that the hypothalamus, left inferior parietal gyrus, right lentiform nucleus and right caudate were decreased in AN . Another meta-analysis aimed to quantify GMV, WMV and CSF alterations with regard to the time course of the disease and weight recovery . They reported that global brain volume loss was more pronounced in adolescent patients than in adults. The authors also showed that following short-term weight recovery (about 4?months), about half of the GMV and CSF normalized, and the amount of WMV seemed to increase more rapidly. Regional analyses showed that some regions seemed to be more vulnerable to change, such as the hippocampus, cingulate gyrus and the midbrain. To our knowledge, only three studies have investigated cortical thickness in patients with AN [4C6]. King et al.  found a significant widespread thinning of the cortex in adolescents and young adults with AN compared to healthy controls. They also investigated 476474-11-0 supplier a group of individuals 476474-11-0 supplier that had recovered from AN, and cortical thickness was not different between this group and the control group, suggesting that structural brain anomalies may be a consequence of malnutrition and is unlikely reflect premorbid traits. This was further supported in a later study , where the authors showed that cortical thickness in the ill AN group normalized following partial weight-restoration, illustrating the rapid reversal of cortical thinning. Lavagnino et al.  found reduced cortical thickness in women with AN, however their findings did not reach significance when correcting for multiple comparisons. They did however find a positive relationship between cortical thickness and body mass index (BMI) in these patients with less than two years of illness duration. Findings of structural brain differences between patients with AN and healthy controls are inconsistent, especially concerning the anatomical location and extent of the differences. In addition, there is a paucity of studies of cortical thickness in AN. The purpose of this study was therefore to estimate and compare brain volumes and regional cortical thickness in young females with AN and healthy controls. We expected to find reduced brain volumes and cortical thickness in patients relative to controls. Methods Participants Twenty-three females were recruited from an inpatient unit at the Regional Department for Eating Disorders in Oslo,.