I considered it and I do still have a strong interest in biopsych, neurology, etc. I know quite a few psychologists who also considered whether to go to med school and become a psychiatrist and ultimately decided it's not for them (there are probably some psychiatrists who resolved the opposite, but I know more psychologists than psychiatrists, so my sample is biased
)
Factors that went into my decision, in the order they occurred to me as I went throughout college:
1) the pressure cooker that is med school is a whole different beast than the pressure cooker that is PhD. For one, I like being able to sleep at night and be awake during the day and not regularly have to be awake for 24 hours at a time, and that is important for my own mental health.
2) Also the curriculum for premed just did not seem particularly interesting to me and are not the types of things I excel in (chem etc is not my thing, what drag... my roommate loved organic chem though- I don't get it) so I decided to pursue things that were more inherently interesting to me (e.g., all the psychology classes, and other sciences here and there as I wanted, like anatomy).
3) To finally become a psychiatrist takes like 8 years, and you don't even get to the psych stuff until a few years in, as opposed to about 6 to become a psychologist and you're doing psychology stuff right off the bat.
4) What mattered most is that I realized I wasn't particularly interested in being a doctor first, and you can't jump straight to psychiatry- the psychiatrists in the psychiatry forum will tell you that you're always a "doctor first." I wanted to be able to get more training in research, teaching, and clinical work (as in therapy) and learning how to do things like cognitive behavioral therapy very well during my time in grad school. Most folks in med school don't get much time for research, and certainly not conducting their own (with rare exception).
5) Ultimately I prefer the types of things that psychologists generally do to the things that psychiatrists generally do. There are always exceptions, but on the whole, psychologists are far more likely to be spending more time (and more regularly) with clients, whereas for psychiatrists, med check appointments may only be like 20 minutes. You don't have the same opportunity (on average) to build the same rapport and spend a lot of time thinking behaviorally about things.
Ultimately, the type of training and the type of work that psychiatrists and psychologists receive/do are quite different. There are people who probably would be equally interested in and successful at either, but before jumping in it's important to really get an idea of what the training and actual work is like for each.
I do feel like it is worth mentioning the difference in pay since I hear that question come up periodically. It is true that psychiatrists make a good bit more money on average, but that's a poor reason to go into any career and probably not enough to keep someone motivated all the way through med school (and right out of school I'm already making what I consider to be quite a decent salary).
But even coming out of undergrad I knew med school was out of the picture I wasn't sure if I wanted to go into PhD programs or not. I still wasn't totally sure what I wanted to do with my life. In college I took classes/majors I thought were interesting and my career plan was "I'll figure it out when I get there." It took me a few years to figure it out, and along the way I just did other things that looked interesting (like working for Americorps, getting a master's in a related field, and doing entry-level clinical work for a few years). If you're still in high school you've still got eons to figure it out
