General Diagnostic Requirements and Differential Diagnosis

The ICD-11’s general diagnostic requirements for personality disorders, along with guidelines for differential diagnosis, will be outlined and explained in this chapter. We initially describe what personality is, followed by the historical background of disordered personality, including traditional personality disorder types from ICD-6 to ICD-10. Subsequently, we highlight the significant role of personality disorder for co-occurring mental disorders, and how they can be naturally intertwined or interact with one another. Finally, we provide ICD-11–based guidelines and considerations for boundaries with other mental disorders, which include autism spectrum disorder, schizotypal disorder, bipolar disorder and cyclothymia, Complex PTSD, secondary personality change, ADHD, dissociative identity disorder, dysthymic disorder, separation anxiety disorder, OCD, conduct-dissocial disorder, substance abuse and other addiction problems, and various impulse control disorders.