French adaptation of the Brief Irritability Test: Factor Structure, Psychometric Properties, and Relationship with Associated Constructs

Irritability is defined as a mood characterized by the proneness to respond with anger and/or aggression upon little provocation. Irritability is a common phenomenon in the general population, as well as a transdiagnostic symptom listed in 15 psychopathological disorders in the Diagnostic and Statistical Manual of Mental Disorders (DSM-V). Several tools have been proposed to measure irritability, but they present discrepancies in their theoretical background, as irritability has been confused with anger and aggression. The Brief Irritability Test (BITe) has been developed (Holtzman, O'Connor, Barata, & Stewart, 2015) to overcome these limitations and allowed to define irritability as a state. This study proposed to validate a French version of this scale, and to examine the relationships between irritability, depression and anger. To this aim, 413 participants completed our French adaptation of the BITe (i.e. the TCI, Test Court d'Irritabilité) as well as validated measures of depression, anger, hostility, aggression, life satisfaction and social support. Descriptive, psychometric (i.e., Cronbach alpha and Spearman correlation coefficients), and factor analyses were conducted. An exploratory factor analysis in sample 1 (n = 209), yielded one single factor. The confirmatory factor analysis in sample 2 (n = 204) showed a reasonable fit of this single factor model explaining 55.5% of the variance and presenting a strong internal consistency ( = .80). Compared to the original English questionnaire, the TCI shares similar unidimensional factor organization and correlations with other constructs, although a gender bias was identified. Irritability was higher among respondents in the age range 17-25, compared to older adults. A hierarchical regression analysis showed that TCI scores significantly predict depressive symptoms when demographics were controlled for. In summary, the TCI presents good psychometric properties and could constitute a valuable tool to evaluate irritability in clinical and research contexts.