If you are applying to clinical psych programs... they are intensely competitive. Most will have pre-reqs for psych classes that you MUST take in order to be admitted.
Several years ago, those were tests and measures, general (obviously), personality, history, cognitive, research, and stats. So, yes, not having the minimum pre-reqs will hurt your chances with those programs.
If you are applying to another field, counseling, social work, or marriage and family therapy... you are less likely to run into those pre-reqs... though most will still require some percentage of classes in the social sciences.
There are exceptions to all rules BUT usually, those sorts of exceptions would only come if the applicant had exceptionally life/career experience. eg: a student grads with a major in film, works in the industry a few years but finds a passion for social work, starts working in foster care, does that for 15 years, and THEN applies to an MSW program...
I'm sure there are other directions that scenario would work as well...
The apps will ALL ask for your Psych GPA and will ask you to list your psych classes.
I ditto the importance of some experience to make sure this is the field for you and ditto the rec for the guide.
Enjoy the process!