1. Three sets of criteria are proposed for assessing animal models of human mental disorders: predictive validity (performance in the test predicts performance in the condition being modelled), face validity (phenomenological similarity) and construct validity (theoretical rationale). 2. The problems inherent in each of these validation procedures are discussed, and their application to the learned helplessness model of depression is examined. 3. It is concluded that whilst the model has good predictive validity, important questions about face validity remain unanswered, and construct validity has not yet been established. 4. The distinctions between animal models and some related experimental procedures are also discussed.