In traumatic neurosis the active cause of illness is not the trifling bodily injury but the affect of fright-the psychic trauma. Similarly, our investigations of many, if not of the majority, of hysterical symptoms have revealed causes which must be described as psychic traumas.
Trauma (psychic), Fixation to the
Endeavors to revive the trauma, to remember the forgotten experience .... if it was an early affective relationship it is revived in an analogous connection with another person .... Thus a man who has spent his childhood in an excessive and since forgotten "mother-fixation," may all his life seek for a woman on whom he can be dependent, who will feed and keep him.
Trauma (psychic) and the Formation of Neurosis
Our researches have shown that what we call the phenomena or symptoms of a neurosis are the consequences of certain experiences and impressions which, for this very reason, we recognize to be retiological traumata. We wish to ascertain, even if only in a rough schematic way, the characteristics common to these experiences and to neurotic symptoms. Let us first consider the former. All these traumata belong to early childhood, the period up to about five years. Impressions during the time when the child begins to speak are found to be especially interesting. The period between two and four years is the most important. How soon after birth this sensitiveness to traumata begins we are not able to state with any degree of certainty.
It may remain an open question whether the retiology of the neurosis should in general be regarded as a traumatic one. The obvious objection is that a trauma is not always evident in the early history of the neurotic individual. Often we must be content to say that there is nothing else but an unusual reaction to experiences and demands that apply to all individuals; many people deal with them in another way which we may term normal. Where we can find no other ~xplanation than a hereditary and constitutional disposition, we are naturally tempted to say that the neurosis was not suddenly acquired, but slowly developed.
In this connection, however, two points stand out. The first is that the genesis of the neurosis always goes back to very early impressions in childhood. The second is this: it is correct to say that there are cases which we single out as "traumatic" ones because the effects unmistakably go back to one or more strong impressions of this early period. They failed to be disposed of normally, so that one feels inclined to say that if this or that had not happened, there would have been no neurosis. It would be sufficient for our purposes even if we had to limit the analogy in question to the traumatic cases. 
TRAUMA PAGES 66, 83-4, 89, 93, 113
trauma, 55, 60, 64, 68-70, 129 Seminar XI