Answer: For acute disorders or personality problems such therapy may be required. For the ordinary personality problems and faults that we all share, like anger, insecurity, jealousy, etc., it is not necessary. It is certainly helpful to become aware of our own faults and personality problems, acknowledge that we have them, and then work to control them. However, the origin of these problems is much deeper than any event from our early life, or even past life. The true origin is maya itself. 
All the faults and negativities of the mind are inherently present in maya. Thus, a mayic mind will automatically have all these faults. The only way to overcome mayic faults is to overcome maya, which happens upon God realization (which is only possible by surrendering to God through bhakti).
As we practice bhakti and purify our mind by attaching it to God, these mayic faults are gradually reduced and we gain more control over them. This is truly curing the disease at its root, instead of merely controlling its symptoms.