Depression usually refers to depressive disorder, and constant recollection of the past is not necessarily depression. This symptom may be caused by physiological depression, or it may be seen in pathological factors, such as during depressive disorder episodes or the presence of obsessive-compulsive disorder, and needs to be judged according to other accompanying symptoms: i. Non-disease factors: people have unforgettable memories of an event or good thing, which may be recalled occasionally and can be expressed as constant recollection of the past; some people may recall their success when they experience setbacks or failures Some people may recall their successful moments and good memories of the past when they experience setbacks or failures, which can also be manifested as constant recollection of the past. If this kind of situation does not affect life and is not accompanied by other psychological disorders or physical symptoms, it is generally a physiological phenomenon, so there is no need to worry too much. Second, the disease factors: 1, depression disorder: depression disorder patients can appear cognitive function abnormalities, such as difficulty in forgetting the bad experiences of the past, decreased attention, prolonged reaction time, lack of concentration, accompanied by low mood, loss of interest in the past favorite things, from the negative perception of things and no confidence in the future, can lead to learning, work efficiency decline; 2, obsessive-compulsive disorder: such patients can appear Subconsciously repeatedly present what they have experienced and cannot get rid of it. When compulsive recollection occurs, it can be manifested as daze, and if the thought is interrupted, it is necessary to rethink from the beginning. Some patients spend a lot of time each day performing repetitive behaviors, such as repeatedly checking, washing, and asking questions, etc. Such symptoms are generally not considered depression. In addition, if the patient constantly remembers the past along with symptoms such as depressed mood, loss of interest in things, slowed thinking, and repetitive behaviors, it is recommended to promptly seek medical attention for psychiatric psychological testing. If depressive disorder or severe obsessive-compulsive disorder is present, timely treatment should be provided accordingly. You should also pay attention to self-regulation in daily life, communicate more with others, and you can do appropriate exercises to relieve stress.