Validation Criteria for Animal Models of Human Mental Disorders - Learned Helplessness As A Paradigm Case

  • Type:#article
  • Year read:
  • Subject: animal models OCD
  • Bibtex: @willner1986
  • Bibliography: Willner, P. (1986). Validation Criteria for Animal Models of Human Mental Disorders: Learned Helplessness As A Paradigm Case. Progress in Neuro-Psychopharmacology and Biological Psychiatry, 10, 677–690.

Why and when I was reading this

I was doing a deep dive into animal models in OCD.

Key takeaways

Animal models should have:

  • Predictive validity
  • Face validity
  • Construct validity

Three criteria for validity of animal models

Predictive validity

Face validity

Construct validity

Predictive validity

Performance in the test predicts performance in the condition/situation being modelled

It is often not possible to test the etiology of mental illness because it is not known. The primary application is to test the effects of therapeutic treatments: the animal model has predictive validity if it discriminates between effective and ineffective treatments.

Dose-response between potency of intervention and clinical outcomes also strengthens the predictive validity. So, if one drug is more effective at targeting certain receptors, it should also display more clinical efficacy.

  • False negatives can occur due to crude measuring instruments or heterogeneity of the disorder

  • False positives can also occur because the outcome measure is not well designed!

    Face validity

    Phenomenological similarity (etiology, biochemistry, symptomatology and treatment)

    Uncertainty in etiology and biochemistry of psychiatric disorders forces us to rely on symptomatology and treatment similarities.

    • Does drug treatment change behavior in the model at reasonable doses?
    • Are the effects seen during the course of chronic drug treatment or only during withdrawal?
    • Are the effects potentiated by, or only present during, chronic treatment?

    Can we be sure that the behavioral output is identical across species? If not, we should not look for identical symptoms in rats or other animals that we would expect in humans.

    Also look for specificity: Are we measuring symptoms specific to the disorder of interest or are these symptoms true for multiple disorders?

    Construct validity

    Theoretical rationale

    If we want to test this at all, we must first assume that it is possible to create theories of psychopathology that are applicable to non-human species.

    Demonstration of construct validity requires two things:

    1. Corresponding constructs are being studied in animals and humans. This presupposes that both the model and the disorder have been sufficiently studied to make an unambigious interpretation of the cognitive changes involved.

    2. A change in the construct is central to the disorder. This means that we must first understand mental disorders in people.

    It might appear that construct validity is simply a more refined version of face validity, but this is not the case. Face validity only requires the demonstration of similarity between the model and symptoms of the disorder being modelled. Construct validity does not require superficial similarity which may, indeed, be absent.

    “These are rather stringent criteria; it is doubtful wether any animal model could meet them fully, in our current state of relative ignorance of the cognitive foundations of psychopathology.”