The article you linked to (Holmes, 2018) is talking about both senarios. The therapist must not be a friend before or during therapy sessions. Dual relationships can interfere with the efficiency of the therapy due to the fact that it can create transference and counter-transference issues.
Transference as a psychological concept refers to the redirection of feelings about one individual to another individual (Short & Thomas, 2015).
Another definition would be
Transfer of feelings originally experienced in an early relationship to other important people in a person’s present environment (Luborsky et al., 2008)
Transference is feelings about another person (including the therapist) being transferred (maybe acted out) towards the therapist.
Imagine a therapist, who is also a friend, says something which upsets the client unintentionally because
(s)he shouldn't say that. (S)he is my friend!
This is where the friendship can affect the client/therapist relationship.
The term ‘counter-transference’ has been applied to a large number of psychological concepts in the therapeutic setting (Little, 1951)
- Counter-transference refers to a specific unconscious attitude towards the client in response to transference from the client (objective transference – responding to
transference from client)
- Counter-transference refers to repressed elements of previous events leading to the
displacement of past feelings from the source to the client (subjective transference
– similar to transference in the client but acting in the opposite direction) (Short & Thomas, 2015).
Counter-transference is feelings about another person (including the client) being transferred (maybe acted out) towards the client.
Imagine something is said by the client, who is also a friend, which changes the therapist's view about that friend. Maybe the revelation changes the dynamics within the friendship they have. This can affect client/therapist relationship through both counter-transference (feelings about the revelation from the client being bounced back to the client) and transference (resulting feelings from the client being bounced back to the therapist).
Dual relationships, no matter how and when they form cause big problems within ethics and efficacy of the therapy sessions, and therefore they are not to occur.
A friend (or family member) should never give therapy to another friend or family member. If dual-relationships do form during sessions, this must be discussed immediately (or as soon as reasonably practicable) with the clinical supervisor in order for discussion to take place regarding signposting and transfer to another therapist.
Little, M. (1951). Counter-transference and the patient’s response to it. In: Langs, R.J. (ed.) Classics in psychoanalytic technique, pp. 143-151.
Luborsky, E.B., O’Reilly-Landry, M. & Arlow, J.A. (2008) Psychoanalysis. In: Corsini, R.J. & Wedding, D. (eds) Current Psychotherapies. Belmont, CA: Brooks/Cole.
Short, F. & Thomas, P. (2015). Core Approaches in Counselling and Psychotherapy. Hove: Routledge