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.
There are many different conditions that are recognized as mental illness. The information on the various types of mental illness that is listed below was attained from WebMD. You can visit their website at www.webmd.com. Below, we have listed the more common types of mental illness : 1.) Anxiety Disorders-People with anxiety disorders respond to certain objects or situations with fear and dread, as well as with physical signs of anxiety or nervousness such as rapid heartbeat and sweating.