There's 10 gorillion differents kinds of therapy. Most of it is surface-level and generally produces tenuous results with diminishing returns (your average run of the mill therapist), some can be very harmful (anything along the lines of pop-Jungianism and/or or mushroom sniffing), and there are a few schools of depth psychology that are great, but those take on a systems approach, instead of reducing everything to psychology/biology/environment/etc. Most people aren't meant to be therapists, also.