The Tripartite Model of Anxiety and Depression

This book reviews the literature in support of unitary, pluralist and tripartite models of anxiety and depression symptoms. The Tripartite Clinical Symptom Inventory (TCSI) is proposed as a measure based on the tripartite model which would be clinically useful, as well as showing strong reliability and validity. The TCSI demonstrates strong reliability when assessed using measures of internal consistency and temporal stability. In addition, the TCSI shows good validity, improving on many aspects of earlier measures. The subscales of the TCSI retain good convergent validity, while discriminant validity of the subscales are also good, especially when assessed using a clinical sample where item variance is greatest. The clinical utility of the TCSI is also specifically investigated, with the new instrument demonstrating excellent ability to differentiate between anxiety and depressive disorders, as well as sensitivity to treatment effects.