What should animal models of depression model?

Area of Science:

• Neuroscience
• Psychiatry
• Pharmacology

Background:

• Animal models are crucial for understanding depression and antidepressant mechanisms.
• Current models face challenges in accurately reflecting the complexity and heterogeneity of human depression.

Purpose of the Study:

• To critically evaluate the aims and methodologies of animal models of depression.
• To propose a refined approach for developing more informative animal models.

Main Methods:

• The article reviews existing literature on animal models of depression and antidepressant action.
• It analyzes the temporal aspects of antidepressant efficacy and symptom heterogeneity.
• It discusses the relationship between depression, anxiety, and underlying behavioral dimensions.

Main Results:

• Antidepressant efficacy in humans exhibits a significant time lag, a factor often overlooked in animal models.
• Depression is a heterogeneous syndrome; modeling specific behavioral dimensions (e.g., negative affect) may be more fruitful than mimicking the entire disorder.
• The close relationship between depression and anxiety suggests shared underlying dimensions.

Conclusions:

• Animal models should aim to replicate either the mechanisms of antidepressant action or the etiological mechanisms of depression, considering the time course of effects.
• Modeling specific, trans-diagnostic behavioral dimensions offers a more tractable and informative approach than attempting to model the entire depressive syndrome.
• This dimensional approach can enhance understanding of both antidepressant mechanisms and the neurobiology of depression and anxiety.