Modelling cognitive affective biases in major depressive disorder using rodents

Area of Science:

• Neuroscience
• Psychiatry
• Animal Behavior

Background:

• Major depressive disorder (MDD) impacts over 10% of the population, yet its causes and antidepressant mechanisms remain poorly understood.
• Current animal models for depression, like forced swim and sucrose preference tests, lack sufficient translational validity for human conditions.
• Cognitive affective biases (CABs) are increasingly recognized as a key feature of MDD in clinical research.

Purpose of the Study:

• To review the development and evaluation of novel animal models for studying MDD.
• To explore the use of 'reverse translation' from human cognitive bias research to animal models.
• To assess the pharmacological and translational validity of new animal models of CABs for MDD research.

Main Methods:

• Utilizing neuropsychological tests developed for humans to create objective measures of CABs in animals.
• Employing judgement bias tasks and affective bias tasks to assess decision-making in rodents under different affective states.
• Reviewing recent research on animal models of CABs and their application to MDD.

Main Results:

• Rodent models exhibiting negative affective states demonstrate pessimistic choices in judgement bias tasks.
• Evidence suggests that judgement bias and affective bias tasks offer improved translational methods for MDD research.
• These novel assays show potential for evaluating antidepressant efficacy and understanding MDD pathophysiology in animals.

Conclusions:

• Animal models based on cognitive affective biases represent a significant advancement in depression research.
• These models offer enhanced translational validity compared to traditional behavioral despair and anhedonia tests.
• Further research into these CAB-based models is crucial for advancing our understanding and treatment of MDD.