A central inspirator for my philosophical counseling practice is Pierre Hadot. Hadot's recurring theme is that philosophy in Antiquity was characterized by a series of spiritual exercises intended to transform the perception, and therefore the being, of those who practice it; that philosophy is best pursued in real conversation and not through written texts and lectures; and that philosophy, as it is taught in universities today, is for the most part a distortion of its original, therapeutic impulse.
So, despite my own many written texts, this is in reality the core of my teaching. It is presented in my first book Meditation as an Art of Life - a Basic reader.
The therapeutic impulse is likely to be rooted in traditions going back to immemorial times. The prehistory of spiritual exercises in Greco-Roman philosophy is first of all in Pythagoreanism, and then, beyond Pythagoras, in magico-religious/shamanistic traditions of respiratory techniques and mnemonic exercises. Greco-Roman philosophy was intimately connected to the mystery schools, and their healing practices. In my blog category, Nordic Shamanism and Forest Therapy, you can find posts that describes the relation between philosophy and shamanism.
As far as I can see, then the spiritual exercises developed in, for example Platonism and neo-Platonism, are refinements of those leading to cataleptic trances and other paranormal experiences (psychic abilities, kundalini, shamanic journey, channeling, possession of gods or demons, ecstasy, etc). They respond to a rigorous demand for rational discrimination, a demand which, as far as I´m concerned, emerges with the figure of Socrates. In this you can see precisely the same as what happened in, for example Tibetan Buddhism and Taoism: a refinement of shamanism into a path of enlightenment (Unio Mystica).
In the Upanishads you can find the oldest accounts of philosophy as a spiritual practice. It is very likely that Plato, or maybe Pythagoras, had knowledge about this tradition.
I also believe that we in Plato saw a warning against ending up in (or stopping at) spiritual crises (see my article Spiritual Crises as the Cause of Paranormal Phenomena), and a warning against false teachers, whose teachings (unknowingly) aim at creating spiritual crises.
Today you can find a fall back into practices which exclusively deals with techniques inducing cataleptic trances and other paranormal experiences. In this way philosophical counseling is a reaction to this.