The objective of this study is to determine and to analyze so-called key sessions in the frameworks of Therapeutic Cycles Model introduced by Mergenthaler and the Energy Model proposed by Caspar. For this purpose, different measures for key session identification are used based on linguistic text variables. The investigation is done for 10 high-frequency, psychodynamic, inpatient, individual therapies consisting of overall 206 therapeutic sessions, all of which were completely videotaped and transcribed. The text analysis was performed using the automated text analysis tool provided by Mergenthaler, which measures the construct of Emotional Tone as a linguistic manifestation of the emotional event and the construct of Abstraction as a linguistic manifestation of cognitive-reflective processes in speech and texts. Feeding these variables into both models, results reveal their coherence: Therapeutic change may occur, whenever an emotional and cognitive-reflective processing of the internal conflicts begins after destabilisation of coherent patterns of behaviour and experiencing. The discussion suggests a more detailed specification of the definition of key sessions in the Therapeutic Cycles Model by Mergenthaler.
