Behavioral Assessment of Antidepressant Activity in Rodent Models

Rodents have long served as pivotal tools for evaluating antidepressant efficacy through a suite of behavioural paradigms that model core facets of depressive disorders. The forced swim test (FST) and tail suspension test (TST) remain the most widely adopted assays, in which a reduction in immobility time following drug administration is interpreted as an antidepressant-like effect. These tests probe the transition between active escape behaviours and passive coping or “behavioural despair,” reflecting underlying motivational and neurochemical states. Complementary models—such as sucrose preference for anhedonia, elevated plus-maze for anxiety-related behaviours and novelty-suppressed feeding for conflict‐induced inhibition—enhance the face and construct validity of preclinical screening. Predictive validity depends on rigorous standardisation of species, strain, sex, age and environmental factors (for example, water temperature and lighting). Recent advances include automated video tracking, severity assessment to refine welfare considerations and integration of inflammatory, genetic and circadian manipulations to dissect mechanisms of treatment response. Collectively, these methodologies accelerate the identification of novel antidepressant candidates and deepen mechanistic insights into mood regulation.

Research from Nature Portfolio

Recent work has elucidated how genetic background influences antidepressant sensitivity in standard behavioural assays. One study compared two common mouse strains and demonstrated that selective serotonin reuptake inhibitors differentially reduced immobility time in both the forced swim and tail suspension tests. These strain-specific effects correlated with marked differences in serotonin transporter binding affinity and synaptosomal uptake kinetics. The findings underscore the critical role of transporter expression levels in shaping behavioural responses and highlight the importance of selecting appropriate rodent strains to enhance the translational reliability of pharmacological screens.

Behavioral Assessment of Antidepressant Activity in Rodent Models publication trend

The graph below shows the total number of articles in behavioral assessment of antidepressant activity in rodent models across all publications each year (not limited to Nature Index journals).

Technical terms

Forced Swim Test (FST): A behavioural assay in which rodents are placed in inescapable water to quantify immobility versus active coping as a screen for antidepressant efficacy.

Tail Suspension Test (TST): A behavioural assay for mice in which immobility during forced suspension by the tail is measured as a proxy for depressive-like behaviour.

Behavioural despair: A phenotype characterised by prolonged immobility in the FST or TST, interpreted as a reduction in escape-driven activity.

Predictive validity: The degree to which a preclinical test accurately forecasts clinical antidepressant efficacy in humans.

Lipopolysaccharide (LPS)-induced model: A rodent paradigm of depression-like behaviour elicited by systemic administration of bacterial endotoxin to evoke neuroinflammation.

References

1. A systematic mapping review of the evolution of the rat Forced Swim Test: Protocols and outcome parameters. Pharmacological Research (2023).
2. Lipopolysaccharide-induced depression-like model in mice: meta-analysis and systematic evaluation. Frontiers in Immunology (2023).
3. Mouse strain differences in SSRI sensitivity correlate with serotonin transporter binding and function. Scientific Reports (2017).
4. DBscorer: An Open-Source Software for Automated Accurate Analysis of Rodent Behavior in Forced Swim Test and Tail Suspension Test. eNeuro (2021).
5. Evidence-based severity assessment of the forced swim test in the rat. PLOS ONE (2023).