How to cultivate healthy psychology from the perspective of life

I don't know whether you ask this question for yourself or for others, but I think you should already know that this person's psychology is a little unhealthy. First, you should know what the problem is, such as lack of self-confidence, pessimism, or unsociable personality ... If you find the right medicine for the problem, if you lack self-confidence, read more determined books, find out your own or his strengths, and give more praise and encouragement. People who like to be withdrawn should communicate more, enlighten him slowly, understand his inner thoughts and overcome his confusion ... It is suggested that reading some simple psychological books can better discover psychological problems and solve them scientifically.