One major challenge in all forms of psychotherapy is how to detect and manage primitive defences. Primitive defences include splitting- where things are viewed as all or none / black or white, projection - where emotions in the self are experienced as coming from outside the self and projective identification - where parts of one's internal self are experienced as being located outside the self.

These defensive operations place a major challenge on all human relationships, including those with a therapist. The defenses pose a threat to the development of the conscious therapeutic alliance, and also undermine the ability to hold complex feelings, and eventually develop the unconscious therapeutic alliance.

In Dr Davanloo's later work and further elucidated through detailed case study over the past 20 years, specific processes to detect and handle these defence processes has been built into the ISTDP model.