Therapist cannot treat his own family members, friends and relatives because,
Psychodynamic predictions tries to explain the unconscious.
If therapist already knows patient,
Psychodynamic predictions made by therapist might get influenced by his own perception of patient.
Narration of patient might get influenced by his perception of therapist.
Ill give an example. If we buy gift to friend, we will buy according to her taste. If we buy gift to stranger, we will buy according to our own taste. So our taste will be reflected only if we are unaware of others taste.
If therapist thinks that he is efficient enough to handle influence, he is actually inefficient.
Belief that a therapist can control influence is false because only conscious is in our hand and not the unconscious.
Belief that unconscious has no effect is false because all psychodynamic predictions are based mainly on unconscious.