Approach-avoidance conflict(AAC)refers to the internal conflict that individuals experi-ence when faced with conflicting approach or avoidance thoughts.It reveals some characteristics of mental disorders,such as anxiety,depression,and addiction represented by excessive tendencies of approach or avoidance.The function of the cortico-limbic-striatal system influences behavioral choices at the neural level during the onset of AAC,and the development of related behavioral paradigms that can better represent AAC behaviors is critical to evaluating the efficacy of drugs and guiding the development of new drugs.This paper summarizes the neural mechanisms,behavioral paradigms,and applications in behavioral pharmacology related to AAC behaviors from the perspective of psychopharmacology with a view to providing new perspectives and methods for the diagnosis and treatment of related neuro-psychiatric disorders.

Animal models are powerful tools for studying the mechanism of depressive disorders and screening antidepressants,but so far there is no model which can stimulate the clinical status of patients ideally.Here,we briefly introduced the research advances in classic animal models of depres-sive disorders,and focused on stress-related animal models,especially those induced by physical and social psychological stressors.The tests for evaluating animal depression behavior were reviewed.In this article,the strengths and weaknesses of each model were analyzed,and the precautions in its application were recommended.Finally,given the high heterogeneity of depressive disorders,this article elaborated on the research progress in models for subtypes of depressive disorders,such as treatment resistant depression,bipolar disorder,peripartum depression,and premenstrual syndrome.