Development and initial reliability and validity of a new measure of distorted maternal representations: The Mother-Infant Relationship Scale.

Distorted maternal representations (DMRs)-mother's ideas, understanding, and feelings about the infant-shape early interaction and the emerging relationship. Distorted interactions reportedly affect infant attachment and socioemotional development and may be associated with maternal early adversity and trauma. Limited measures are available that could be used as screening tools of DMRs. The aims of this study were to (a) describe the development of the Mother-Infant Relationship Scale (MIRS) and (b) to evaluate its psychometric properties. The development and validation of the MIRS closely followed standard guidelines for the development of psychometric tests. Psychometric properties were examined across two samples: 78 adult psychiatric patients with features of borderline personality and 86 individuals from a nonclinical sample (N = 164). The scale demonstrated excellent internal consistency (Cronbach's α = .91) for the clinical sample and adequate internal consistency (.78) for the nonclinical sample, excellent test-retest reliability (intraclass correlation coefficient = .81), and good concurrent validity with an observational (Pearson's correlation coefficients = -.35 to -.54) and a representational measure (.53). Factor analysis revealed three components: DMRs specific to (a) maternal hostility/rejection of the infant, (b) issues about parenting/attachment, and (c) anxiety/helplessness about infant care. Findings suggest that the MIRS is a reliable and valid screening tool of DMRs. Potential uses in clinical and research settings are discussed.