Considering Lacan's reading of the case study where he notes that Schreber used common language to explain his otherwise expressively rich psychoses, approaching the sinthome but failing to escape the detrimental symptoms of psychosis, Russell Grigg observes that "there is a moment when [Schreber] is called, interpellated, by—or perhaps better 'in'—the Name-of-the-Father. This is when the lack of the signifier declares itself, and it is sufficient to trigger the psychosis."
Schreber's use of common language to describe his complex psychoses, as observed by Lacan, highlights a tension between expressiveness and psychosis. Grigg expands on this by suggesting that the "Name-of-the-Father" acts as a trigger for psychosis when Schreber's lack of a signifier becomes apparent.