Aim of the study:
This study investigated the association between therapist interventions and patient defensive functioning in low-alliance and high-alliance sessions over the course of short-term dynamic psychotherapy (STDP) (n= 22).

Subject or material and methods:
Lag sequential analysis was used to determine if there were predictable sequences of therapist interventions and patient defenses in low-alliance and high alliance sessions and whether these two sequences differ.

Results:
The results of this study suggest that sequences between alliance session groups are different. Specifically, defense interpretation depth unfolds in a predictable fashion during a low-alliance session while supportive strategies appear more predictable during high-alliance sessions.

Discussion:
The statistical trends obtained in this study are discussed in light of prior research studies in this area. Specifically, differences between low and high alliance sessions are discussed.

Conclusions:
Defense interpretation depth is a clinical construct that warrants further study in psychotherapy research.