Hi Serasera!
I just graduated with a BA in Psych (biopsychology concentration) and will be attending medical school in the fall. As such, I can give you a little bit of information regarding the route to becoming a psychiatrist.
Your first step, were you to want to pursue this career, would be gaining an acceptance into medical school. Required coursework includes (at a minimum) 1 year of: Biology, Inorganic/General Chemistry, Organic Chemistry, and Physics. All require a laboratory componant. Many schools also required a year of English/Writing and sometimes 1-2 semesters of Calculus. Finally, a few schools have additional required electives (e.g. - in social science, biochemistry, etc).
After taking these course (and hopefully averaging a science and overall GPA >3.5), you'll want to prepare for and take the MCAT. This standardized examination is computer based and consists of multiple choice questions covering all of the aforementioned core (4) science subjects. There are also two essays on various topics, and these test logical reasoning, persuasion, and argument formation rather than scientific knowledge.
Throughout college you are going to want to try and build your resume with activities such as clinical experience, volunteering, leadership roles, and research. This is obviously a lot and not everyone covers all of these areas. It is preferable to actually become deeply involved in a couple of activities (e.g. - spend a year researching) rather than to superficially become involved in many activities (e.g. - joing 8 different clubs and researching for only a summer).
Finally, you will need letters of recommendation (3-5 usually), and at least 2 from science faculty. AMCAS, a standardized application system (online) is available in June of the year that you are applying, and you will want to complete this as soon as possible. After sending the application to all of the medical schools that you are interested in (and competitive for), they will send your individual secondary applications in mid-late summer. You fill these out, return them (along with $
🙄), and wait. You may be granted an interview anytime from late August to late May of the following year. Apply broadly even if your stats are strong...competition is fierce and often times it appears to be a crapshoot

.
Once into medical school, you have two years of didactic lecture and two years of clinical clerkships (rotations)...one of which will be in psychiatry. If your fourth and final year of medical school, you would then apply to residencies in psychiatry. After interviewing at various residency programs, you will eventually be matched into one of them. So begins the four year long residency, potentially followed by a fellowship if you want further specialization and training.
I hope that helped! Feel free to ask any clarifying questions that you may have!
🙂