Cheerful people may also get depression for the following reasons: first, the causes of depression are not particularly clear, especially the biological causes of depression may be related to genetic inheritance, brain structure, nervous system development and neurotransmitter secretion abnormalities, and cheerful people may also be at risk of these biological factors; second, cheerful people are not necessarily psychologically healthy, some people may superficially appear to be more lively and cheerful, not concerned about these small details, but in fact these people may be suppressing their bad emotions, and may actually be more sensitive and vulnerable inside. The second is that a cheerful person is not necessarily a psychologically healthy person; some people may appear to be more lively and cheerful, not concerned about these small details, and are more enthusiastic about people, but in fact these people may be suppressing their own bad emotions, and may actually be more sensitive and vulnerable, and may be depressed when they are alone; the third is that a psychologically healthy and cheerful person may also encounter a lot of stressful life events, and if the patient is beyond the patient’s tolerance, the patient may also encounter these biological factors at risk. Thirdly, a mentally healthy and cheerful person may encounter a lot of stressful life events that are beyond the patient’s ability to cope with, and the patient may also suffer from depression.