Exploring the Link Between Insomnia and Personality Disorders: A Comprehensive Systematic Review

Insomnia is one of the most diagnosed sleep disorders, affecting approximately 30% of the world's population. Insomnia significantly impairs psychological well-being and increases vulnerability to psychiatric disorders, particularly anxiety and depression. While numerous studies have highlighted the role of specific personality traits in insomniacs, research has not yet elucidated which features of each personality disorder (PD) are most closely associated with insomnia. This systematic review aimed to fill this gap by summarizing the results of studies that examined the co-occurrence of insomnia and PDs. None of the included studies specifically focused on Cluster A PDs, only one study specifically looked at Cluster C PDs, and 3 studies investigated all PD Clusters. Most studies focused on Cluster B PDs, revealing a specific link between insomnia and the distinctive features of borderline PD, in particular: marked emotion dysregulation and impulsivity, a tendency to exaggerate symptoms, and discouragement about treatment outcomes. These findings may contribute to the development of more personalized assessment and intervention protocols for insomniacs with borderline PD.