The Lexicon of Crisis: A Psycho-Forensic Linguistic Architecture for Real-Time Suicide Risk Detection Integrating Big Data, Corpus Evidence, and Theoretical FrameworksPsycho-Forensic Linguistic Surveillance Initiative (PFLSI)

Abstract

Suicide claims over 700,000 lives annually and remains one of the most preventable yet persistent crises in global public health. The Psycho-Forensic Linguistic Surveillance Initiative (PFLSI) is a longitudinal, multi-paper research programe dedicated to constructing a culturally calibrated, big-data-enabled computational framework for the early detection of suicidal ideation through systematic lexical and discourse analysis. Series Paper 1, Ishfaq, Ahmad, and Sultan (2025), established a validated corpus of N=140 Pakistani suicide notes (1998–2023), identifying gendered thematic markers, pronoun patterns, apologetic discourse, and darkness metaphors using Sketch Engine. Series Paper 2, Ishfaq and Sultan (2026), expanded the empirical base to a 452,000-token Suicide Discourse Corpus (SDC) drawn from four heterogeneous English-language sources crisis helpline transcripts, Reddit communities, published personal narratives, and farewell notes — and applied rigorous Keynes analysis (G²), USAS semantic domain profiling, Mutual Information collocational analysis, and grammatical frequency analysis against a matched 449,800-token control corpus. Together, these studies produced converging, large-scale empirical evidence for a distinctive and statistically robust lexical signature of suicidal crisis: elevated pain, absolutist, death, and isolation vocabulary; depleted future-tense, positive-evaluative, and social solidarity language; and culturally specific registers of honor-shame discourse and relational guilt absent from Western corpora. The present paper, synthesizes and substantially advances these foundations along three critical axes. First, it develops a unified, seven-framework theoretical architecture, integrating Shneidman's psychache theory, Joiner's Interpersonal Theory of Suicide, Beck's cognitive model of hopelessness, O'Connor's Integrated Motivational-Volitional model, Pennebaker's Linguistic Relativity Theory, Lakoff and Johnson's Conceptual Metaphor Theory, and Menon's Narrative-Crisis Model, demonstrating how each framework's predictions are empirically instantiated in the combined corpus evidence of Series Papers 1 and 2. Second, it presents the complete architectural specification of the Psycho-Forensic Linguistic Surveillance (PFLS) pipeline, a proposed seven-layer big-data NLP system designed to ingest heterogeneous text streams, extract theoretically grounded linguistic features, apply culturally calibrated multilingual modelling, stratify real-time risk across four tiers, and generate explainable clinician alerts with SHAP-attributed feature rationale. Third, it addresses the ethical, policy, and governance dimensions of responsible deployment, articulating an ethical minimalism framework for linguistic surveillance in suicide prevention. Together, the three papers of the PFLSI programe constitute a paradigm shift: repositioning language itself as the earliest accessible biomarker of psychological crisis, and providing the empirical, theoretical, and architectural foundations for a next-generation, population-level suicide prevention infrastructure.