The criteria and symptoms are basically the same things by different names, one is using the psychiatric nomenclature (Diagnostic Criteria) and the other (Symptoms) subjectively reported by the individual.
Below will be given a case study of an individual diagnosed with Major Depression and PTSD. You will notice many times the two illnesses are diagnosed together since they often times occur together, one exacerbating the other.
This individual is a female approximately 35 years old. She complains of depressed mood most of the day, nearly every day; Insomnia nearly every day; psychomotor retardation (which is slowing of her responses and reactions to things happening around her); fatigue; diminished ability to think or concentrate. No organic factor initiated or maintained this disturbance. It is not a normal reaction to the death of a loved one. At no time during this disturbance have there been delusions or hallucinations in the absence of prominent mood symptoms. It is not superimposed on Schizophrenia, Schizophreniform Disorder, Delusional (Paranoid) Disorder or Psychotic Disorder, Not otherwise Specified.
The patient has been the survivor of repeated sexual abuse from her first remembrances until the age of 26 years. She was also on active duty for six years during which time she was “in-country” in various locations around Europe, Asia, the Central and South Americas. At this point that is all that she is cleared to discuss. She has recurrent and intrusive distressing recollections of the events. She makes efforts to avoid activities or situations that arouse recollections of the trauma. She feels detached and estranged from others. She has a restricted range of effect. She has difficulty falling asleep, hypervigilance and an exaggerated startle response. She has periods of memory loss regarding the latest episodes of trauma. Currently she will “come to” (her words) and not remember the previous events.