Assessment of hypnotic processes and responsiveness in a clinical context

The present study was designed to investigate in a clinical situation whether differences in measured hypnotizability validly reflect differences in hypnotic processes and to what extent factors deemed extraneous to hypnosis--such as resistance--influence hypnotic responding. To answer this question, Dutch versions of relevant scales had to first be developed. The factorial validity and reliability of a Dutch translation of the Resistance Toward Hypnosis Scale (DRHS) and a shortened Dutch version of the Phenomenology of Consciousness Inventory (DPCI) were investigated in a sample of 205 psychiatric patients. The DRHS proved to be factorially valid and reliable, and two subscales, Trance and Reality Orientation, derived empirically from the DPCI showed good to satisfactory reliability. In a second study with a subsample of 99 psychiatric patients, hypnotizability as measured by the Stanford Hypnotic Clinical Scale for Adults was strongly and positively related to DPCI Trance scores and moderately and negatively related to DPCI Reality Orientation and DRHS Resistance scores. It is concluded that hypnotizability as measured in a clinical context under standard conditions is strongly related to hypnotic experiences over and above the moderate effects of resistance toward hypnosis and hypnotic suggestions. Standard hypnotizability assessments appear to be similar in their meaning in an experimental and clinical context.