Background: It is thought that the decision rule for a positive diagnosis of Posttraumatic Stress Disorder (PTSD) may be too restrictive, leaving too many victims of a trauma out in the cold for care, compensation, etc. Several authors have proposed the concept of Subthreshold or Partial PTSD (PPTSD). This concept considers that a subject may present a number of symptoms below threshold for criteria C or D (subthreshold syndromes) and may even present without any symptom for one or more of the criteria B, C and D (partial syndromes).
Method: Data have been collected by means of the Composite International Diagnostic Interview (CIDI) PTSD-module, in a group exposed to two different traumatic events (130 fire victims and 55 car accident victims). The syndrome patterns has been assessed by means of hierarchical class analyses. Each of the criteria B, C and D has been analyzed separately, showing the symptom patterns as hierarchically order clusters.
Results: Depending on the threshold used for criterion C (i.e. 3 or 2 symptoms), 18.4 and 22.7% of the subjects respectively satisfy the criteria for PTSD. 8.7% of the subjects show subthreshold syndromes. 60.7% of the subjects show partial syndromes and 16.7% of the subjects have partial syndromes while fulfilling criterion F, i.e. a clinically significant impairment in functioning.
Conclusions: The results show a considerable number of partial and subthreshold syndromes. It is argued that subthreshold syndromes and partial syndromes, which fulfill criterion F, should be regarded as specific nosological categories or as specified PTSD subcategories, i.e. subsyndromal or partial PTSD.