Dynamic changes of serotonin levels induces depression-like behaviour in mice with high-fat diet

Abstract

Introduction of SSRI as the first-line pharmacotherapy options for depression, which purpose is to increase the concentrations of 5-HT in brain and help reduce depressive symptoms. However, there are still many limitations to the effectiveness of these treatment strategies, 30-40% of patients do not respond to treatment at all, and even suicide occurs. In the present study, we revealed that increasing brain 5-HT concentration is not the best treatment options. When we injected sufficient amounts of 5-HT into the lateral ventricular region of mice, it actually caused depression-like behavior in the animals. The second study on high-fat fed induces depressive symptoms in mice demonstrated that 5-HT concentration in brain showed a tendency to increase first and then decrease. Both experiments indicated that if SSRI are administrated to the patient in the acute phases of depression, it may lead to exacerbation of mental disorders or suicidal tendencies.