There are very few people in the position to choose a child psychiatry course because only those becoming child psychiatrists would study this field, and they are usually in residency or fellowship programs when they do. Courses tend to be required and not elective, so there’s little selection. The simple mistake many people make is that they refer to psychiatry and psychology interchangeably, but in any other college setting besides medical school or post-graduate medical studies, it is much more likely people will take child psychology courses. The term psychiatry is typically reserved for those people who study the mental issues of children from a medical doctor perspective.
If, as it happens, a person is looking for a child psychiatry course as previously mentioned, the person would usually take such a course in conjunction with medical studies, often during residency. More than psychiatrists might interested in child psychiatry, and just about any person planning on becoming a pediatric specialist could want insight into the emotional and psychological motivations of children being treated for illness. The type of courses would be highly dependent on a residency program, and some students are expected to infer from what they learn on the job, while others could have formal instruction.
It might also be possible to take a child psychiatry course that is a general introduction to the field. Additionally, pediatric specialists could take child psychology courses at nearby universities. One difference in approaches, and this would depend on the program, too, is that a child psychiatry course might cover more about medical and drug management of conditions, where the child psychology course could encompass more on talk/therapeutic interventions.
For those people who look to a child psychiatry course in regular college studies, looking in the psychology department or possibly child development department instead would help them. Lots of people want a good general introduction to the topic or others may be interest in an eventual major in this field. At the doctoral level, there are programs that specifically focus on child and adolescent psychology, and students wishing to have this focus would take as many courses as they could in these areas, and would naturally take all classes that would fulfill university requirements for a major.
Ultimately, how to choose the best class depends very much on focus and goals. Medical students, residents or fellows may study in a child psychiatry course as part of training. People might take a child psychology course for personal information, as part of a major requirement, or to explore interest in the field. People who are gaining their doctorates in child and adolescent psychology will take many advanced courses, often to fulfill interest and graduation requirements, simultaneously.