Objective: This study was designed to compare the depression-related behavior-inducing potentials of 10-day immobilization stress and chronic mild stress in adult female rats.

Materials and Methods: Adult Wistar rats were randomly divided into three groups (n=10) as control, immobilization stress (45 minutes per day) and chronic mild stress. Both stress protocols were applied for a period of 10 days. Behavioral tests were performed when the rats were in diestrus.

Results: In the forced swimming test, immobility behavior in the immobilization stress group and chronic mild stress group was significantly higher than the control group (P<0.05 and P<0.001, respectively). Additionally, there was a significant decrease in swimming behavior in the immobilization stress and chronic mild stress groups compared to the control group (P<0.05 and P<0.01). In the open field test, the percentage of time spent in the central area was lower, and latency in the central area was longer in the immobilization stress group (P<0.05). The frequency of the rearing behavior in the immobilization stress group was lower than the control group (P<0.01). The percentage of body weight change was significantly higher in the chronic mild stress group compared to the control group (P<0.001).

Conclusion: We suggest that the depression-related behavior-inducing potential of the chronic mild stress model is more prominent than the immobilization stress model by means of 10-day stress protocol in female rats. However, our chronic mild stress protocol might have some risks in animals during the pregnancy and postpartum period due to significant weight loss.