In most colleges it takes 6 years to become a psychologist. 4 years for bachelor degree and 18 months to 2 years for Masters Degree. You can work as an assistant to psychologist after completing 4 years bachelor's degree.
If you attend a four-year university right after high school it takes 9 years to get your phd if thats the degree you would like. I am going to college for the same thing but I am using sociology as my double major (: