Hi Pitbull found this:

Complex PTSD

Complex PTSD (sometimes called "Disorder of Extreme Stress") is found among individuals who have been exposed to prolonged traumatic circumstances, especially during childhood, such as childhood sexual abuse. Developmental research is revealing that many brain and hormonal changes may occur as a result of early, prolonged trauma, and these changes contribute to difficulties with memory, learning, and regulating impulses and emotions. Combined with a disruptive, abusive home environment that does not foster healthy interaction, these brain and hormonal changes may contribute to severe behavioral difficulties (such as impulsivity, aggression, sexual acting out, eating disorders, alcohol/drug abuse, and self-destructive actions), emotional regulation difficulties (such as intense rage, depression, or panic), and mental difficulties (such as extremely scattered thoughts, dissociation, and amnesia). As adults, these individuals often are diagnosed with depressive disorders, personality disorders, or dissociative disorders. Treatment often takes much longer than with regular PTSD, may progress at a much slower rate, and requires a sensitive and structured treatment program delivered by a trauma specialist.

Basically i assume (and my partner has been told this by his psych) ptsd is usually from one life threatening event,complex is usually from more than one event.
Hope this helps.