Stratified sampling is often used when one or more of the stratums in the population have a low incidence relative to the other stratums. Convenience sampling is used in exploratory research where the researcher is interested in getting an inexpensive approximation of the truth.
Sometimes symptoms of a mental health disorder appear as physical problems, such as stomach pain, back pain, headache, or other unexplained aches and pains.
For a general list of signs and symptoms, visit our Seeking Services section. Below are specific symptoms associated with common mental health disorders. These lists are very brief â there are many and varied symptoms that can occur depending on the disorder someone is experiencing and the severity of their illness.