This suggests that this sub-scale does not reliably assess patients’ self-reported blunted affect symptoms and is likely due to the nature of blunted affect.

The CAINS Self-report Expression Subscale, had a low internal consistency score. We found that blunted affect items common across all instruments assess: gestures, facial expressions and vocal expressions. On average the instruments take 15–30 minutes to administer. We reviewed 30 full-text articles and included 15 articles and 10 instruments in this systematic review. Studies reporting on the psychometric properties of instruments assessing blunted affect in patients with schizophrenia were included. In light of this, we aim to provide researchers and clinicians with a systematic review of the different instruments used to assess blunted affect by providing a comparison of the type, characteristics, administration and psychometric properties of these instruments. Since then, several new instruments assessing negative symptoms with subscales measuring blunted affect have been developed. The work of Abrams and Taylor and their development of the Rating Scale for Emotional Blunting in the late 1970’s was an early indicator that blunted affect could indeed be assessed reliably.

Patients with blunted affect have difficulty in expressing their emotions. Blunted affect, also referred to as emotional blunting, is a prominent symptom of schizophrenia.

What is a flat affect