Mental Health and Digital Therapy Apps as Void Objects: Clinical Opacity, Engagement Architecture, and Documented Harm — A Within-Domain Spearman Convergence

Twelve digital mental health platforms (BetterHelp, Talkspace, Cerebral, Done, and others) scored on O (algorithm transparency for therapist matching, clinical outcome disclosure), R (personalized content escalation, crisis response adaptivity), and C (subscription dependency, data portability, therapist relationship lock-in). Spearman ρ between Void Index and documented harm from FTC settlements, NHS Digital adverse event reporting, and JMIR Mental Health literature. EU AI Act Annex III §5, GDPR Article 9 special category health data.