Abstract
Abstract There is a broad consensus that the commonly used clinician administered rating scales for assessment of negative symptoms share significant limitations, including: 1) reliance upon accurate self-report and recall from the patient and caregiver; 2) potential for sampling bias and thus being unrepresentative of daily life experiences; 3) subjectivity of the symptom scoring process and limited sensitivity to change. These limitations led a work group from the International Society of CNS Clinical Trials and Methodology (ISCTM) to initiate the development of a multimodal negative symptom instrument. Experts from academia and industry reviewed the current methods of assessing the domains of negative symptoms including diminished (1) Affect; (2) Sociality; (3) Verbal communication; (4) Goal-directed behavior; and (5) Hedonic drives. For each domain they documented the limitations of the current methods and recommended new approaches that could potentially be included in a multimodal instrument. The recommended methods for assessing negative symptoms included ecological momentary assessment (EMA), in which the patient self-reports their condition upon receipt of periodic prompts from a smartphone or other device during their daily routine; and direct inference of negative symptoms through detection and analysis of the patient’s voice, appearance or activity from audio/visual or sensor-based (e.g., GPS, actigraphy) recordings captured by the patient’s smartphone or other device. The process for developing an instrument could resemble the NIMH MATRICS process that was used to develop a battery for measuring cognition in schizophrenia. Although the EMA and other digital measures for negative symptoms are at relatively early stages of development/maturity and development of such an instrument faces substantial challenges, none of them are insurmountable.