This is a protocol for a Cochrane Review (Intervention). The objectives are as follows:

1. The primary objective of this review is to determine if antipsychotic drugs are clinically effective in improving weight gain and reducing the core psychopathology of AN when compared to placebo.

2. Secondary objectives are:
(a) To investigate whether different classes/types of antipsychotics (eg. atypical versus typicals) differ in efficacy or acceptability for AN;
(b) To compare the efficacy and acceptability of treatments (e.g. inpatient programs, specific psychotherapies) for AN combined with an antipsychotic drug versus the same intervention(s) alone (i.e. without any drug);
(c) To investigate if antipsychotics may be effective in ameliorating the core psychopathology of AN (e.g. distorted body image, morbid preoccupation with weight and shape) independently of the effect in weight restoration;
(d) To identify factors (clinical, methodological) which predict response to treatment with antipsychotic drugs.