Introduction: Brain volume deficits of grey matter (GM) and white matter (WM) are
often found in patients with anorexia nervosa (AN). However, until recently, little was known
about the influencing factors of these brain volume alterations, nor their exact quantification and
Methods: This review addresses these open questions and further explores what is now known
about the underlying pathobiology and the clinical consequences including human studies as well as
animal studies mimicking anorexia nervosa in rodents.
Results: GM was reduced by 3.7% in adults and 7.6% in adolescents with AN. WM was reduced on
average 2.2% in adult patients and 3.2% in adolescents. Most volume deficits in adults are reversible
after long-term recovery; for adolescents, data are less clear. The main influencing factors for
GM were absolute lowest weight at admission and illness duration. Cerebellar and WM reductions
at admission predicted clinical outcome at one year follow-up. New studies found GABA receptor
changes in GM and astrocyte loss in both GM and WM, as well as a possible role for oestrogen
deficit. All three could partly explain clinical symptoms of anxiety, rigidity and learning impairments
in patients with AN.
Conclusion: Brain volume deficits in AN seem to play a causal role in the course and the prognosis
of AN. A better understanding of these brain changes could lead to more targeted therapies for patients
with AN, including astrocyte-directed approaches.