The subjectivity related to the field of mental health has a lot to do with the many different versions of a particular mental illness. Someone with MDD may by suffering from a decreased appetite and sleep, while another person with atypical depression may be experiencing an increased appetite and sleep. Mental illness may affect everyone differently even if the diagnosis is the same. That’s why we cannot assume that we understand what everyone is going through. . .
via Same Mental Illness, Different Perception Of Reality — DSM (Defeating Stigma Mindfully)