Within the depth-psychology corpus, personality disorders occupy a liminal diagnostic territory: they are neither straightforwardly symptomatic like the classical neuroses nor as severely disorganizing as the psychoses, yet they signal pervasive, structurally embedded failures of self-regulation, affect modulation, and relational functioning. The literature surveyed here converges on several major tensions. First, etiological: Schore’s neurobiological account traces borderline and narcissistic configurations to critical-period dyadic failures in affect regulation, implicating orbitofrontal maturation and attachment disruption, while Herman and Courtois read the same presentations as sequelae of chronic trauma and betrayal. Second, taxonomic: Hart and Nijenhuis argue that borderline personality disorder overlaps so substantially with complex PTSD and dissociative disorders that differential diagnosis becomes genuinely fraught. Third, therapeutic: Leichsenring’s meta-analytic evidence and Shedler’s efficacy review both demonstrate that long-term psychodynamic psychotherapy yields large effect sizes specifically for personality disorders, challenging briefer cognitive-behavioral alternatives. Yalom and Flores address the clinical management of these presentations in group contexts, while Hollis connects dissociative identity phenomena to Jung’s conception of the complex as a ‘splinter personality.’ Across all positions, the personality disorders serve as a site where biological, developmental, traumatological, and depth-psychological explanatory frameworks collide most productively.