a1 Section of Eating Disorders, Institute of Psychiatry, King's College London, UK
a2 Department of Child Psychiatry, Chiba University Hospital, Chiba, Japan
a3 Division of Psychological Medicine, Eating Disorders Research Unit, Department of Academic Psychiatry, King's College, Guy's Hospital, London, UK
a4 Division of Psychological Medicine and Social Genetic and Developmental Psychiatry Centre, Institute of Psychiatry, King's College London, UK
a5 Division of Clinical Neuroscience, Chiba University Centre for Forensic Mental Health, Chiba, Japan
a6 Department of Psychiatry, Chiba University Graduate School of Medicine, Chiba, Japan
Background Studies of patients with anorexia nervosa (AN) have shown that they do not perform well in set-shifting tasks but little is known about the neurobiological correlates of this aspect of executive function. The aim of this study was to measure serum brain-derived neurotrophic factor (BDNF) and to establish whether set-shifting difficulties are present in people with current AN and in those recovered from AN, and whether serum BDNF concentrations are correlated with set-shifting ability.
Method Serum BDNF concentrations were measured in 29 women with current AN (AN group), 18 women who had recovered from AN (ANRec group) and 28 age-matched healthy controls (HC group). Set-shifting was measured using the Wisconsin Card Sorting Test (WCST). Eating-related psychopathology and depressive, anxiety and obsessive–compulsive symptomatology were evaluated using the Eating Disorder Examination Questionnaire (EDEQ), the Hospital Anxiety and Depression Scale (HADS), and the Maudsley Obsessive–Compulsive Inventory (MOCI) respectively.
Results Serum BDNF concentrations (mean±s.d.) were significantly lower in the AN group (11.7±4.9 ng/ml) compared to the HC group (15.1±5.5 ng/ml, p=0.04) and also compared to the ANRec group (17.6±4.8 ng/ml, p=0.001). The AN group made significantly more errors (total and perseverative) in the WCST relative to the HC group. There was no significant correlation between serum BDNF concentrations and performance on the WCST.
Conclusions Serum BDNF may be a biological marker for eating-related psychopathology and of recovery in AN. Longitudinal studies are needed to explore possible associations between serum BDNF concentrations, illness and recovery and neuropsychological traits.
(Received August 28 2007)
(Revised June 16 2008)
(Accepted June 26 2008)
(Online publication August 28 2008)