In his seminal book on depression, The Noonday Demon: An Atlas of Depression, Andrew Solomon quotes psychoanalyst and linguist Julia Kristeva to articulate the profound, often absolute, inability of depressed individuals to communicate their suffering through language. 

Solomon draws upon Kristeva's work, particularly her book Black Sun: Depression and Melancholia, to explain that depression causes a breakdown in the ability to use language to represent internal experience. 

Key themes from Kristeva quoted or referenced by Solomon regarding this silence include:

• "Foreigners in their Maternal Tongue": Kristeva posits that the depressed person becomes a "foreigner" to their own language, finding it impossible to use words to express their profound, "unnameable" pain.
• The Inability to "Concatenate": Kristeva writes that, "Faced with the impossibility of concatenating, they [the depressed] utter sentences that are interrupted, exhausted, come to a standstill. Even phrases they cannot formulate.".
• Silence and "Asymbolia": Solomon highlights Kristeva's observation that when speech fails, the depressed person sinks into "the blankness of asymbolia" or a chaotic silence, where the ability to convey meaning is completely lost.
• Melancholy as "Dead Language": Kristeva describes the speech of the depressed as a "dead language," noting that they "speak of nothing, they have nothing to speak of". 

Solomon utilizes these insights to explain that the "worst of depression" is often the isolation of being unable to describe one's mental state, leading to a "strangulation" of affect where emotion is trapped and cannot be released through words.