Objectives: To provide psychometric data on a self-report measure of major depressive disorder (MDD) and to determine whether somatic symptoms are nonspecific or count toward the diagnosis.
Setting: Data from the National Spinal Cord Injury Statistical Center representing 16 Model Spinal Cord Injury Systems.
Participants: Eight hundred forty-nine people with spinal cord injury who completed a standardized follow-up evaluation 1 year after injury.
Interventions: Not applicable.
Main outcome measures: The Patient Health Questionnaire-9 (PHQ-9), a measure of MDD as defined by the Diagnostic and Statistical Manual of Mental Disorders, 4th Edition . We computed descriptive statistics on rates of depressive symptoms and probable MDD, evaluated internal consistency and construct validity, and analyzed the accuracy of individual items as predictors of MDD.
Results: Exactly 11.4% of participants met criteria for probable MDD. Probable MDD was associated with poorer subjective health, lower satisfaction with life, and more difficulty in daily role functioning. Probable MDD was not related to most demographic or injury-related variables. Both somatic and psychologic symptoms predicted probable MDD.
Conclusions: The PHQ-9 has promise as a tool with which to identify probable MDD in people with SCI. Somatic symptoms should be counted toward the diagnosis and should alert health care providers to the likelihood of MDD. More efficient screening is only one of the quality improvement efforts needed to enhance management of MDD.