When you need a little bit of help coping with your busy life, your friends will all recommend that you "go see someone" or "see a shrink" or "make an appointment with a counselor." When you question them more closely about who you should see, however, you may notice that a lot people aren't sure whether these slang terms refer to a psychologist or a psychiatrist. What's the difference? How can you tell? Under what circumstances would you go to one or the other? This article should clear up any confusion.
The biggest difference between a psychologist and a psychiatrist is that a psychologist is a scientist, whereas a psychiatrist is a doctor. Psychologists have a broader focus. They are trained to study problems of the mind from a scientific standpoint, with the aim of developing or testing new treatments and better understanding mental disorders. By contrast, psychiatrists are focused specifically on improving the lives of their specific patients and alleviating their worry by treating the underlying medical cause of their symptoms.
Psychologists can have a wide variety of specialties, ranging from evolutionary psychology to abnormal psychology depending on what aspect of mental function they study. Psychiatrists have specialties too, but these depend on who they are helping and how they're helping. A forensic psychiatrist, for example, might assist in solving a murder, while a child psychiatrist would specialize in helping young people with their mental issues. There are even some specialty fields which are common between the two professions.
The major difference between a psychologist and a psychiatrist for you the patient is that while a psychologist will try to help you with behavioral techniques such as taking out your anger safely, facing your fears, or just talking it out. A psychiatrist, on the other hand, will prescribe medications to treat the medical cause of your mental problem (an imbalance in chemicals, for instance). Although a small fraction of clinical psychologists are able to prescribe medicines, this is the almost exclusive domain of psychiatrists.
To become a psychologist, you must study get a Bachelor of Science in Psychology at a university, followed by a Masters and a Doctorate. Then you can get a job helping people or analyzing behavior to help them develop better ad models. To become a psychiatrist, you must have a Bachelor's degree and a degree in medicine. Then you can get a job at a clinic or hospital. Since people with doctorates and medical doctors are both referred to as "doctor", there is often some confusion between the two professions.