Depression Diagnoses and Fundamental Frequency-Based Acoustic Cues in Maternal Infant-Directed Speech

F₀-based acoustic measures were extracted from a brief, sentence-final target word spoken during structured play interactions between mothers and their 3- to 14-month-old infants, and were analyzed based on demographic variables and DSM-IV Axis-I clinical diagnoses and their common modifiers. F₀ range (ΔF₀) was negatively correlated with infant age and number of children. ΔF₀ was significantly smaller in clinically depressed mothers and mothers diagnosed with depression in partial remission, relative to non-depressed mothers, mothers diagnosed with depression in full remission, and those diagnosed with depressive disorder not otherwise specified. ΔF₀ was significantly lower in mothers experiencing their first major depressive episode relative to mothers with recurrent depression. Deficits in ΔF₀ were specific to diagnosed clinical depression, and were not well predicted by elevated self-report scores only, or by diagnosed anxiety disorders. Mothers with higher ΔF₀ had infants with reportedly larger productive vocabularies, but depression was unrelated to vocabulary development. Implications for cognitive-linguistic development are discussed.