The confusion of personality disorders with Axis I disorders can be traced in part to inadequacies of assessment instruments and diagnostic criterion sets. However, it also reflects the absence of adequate conceptualization. If Axis I continues to include early onset, chronic impairments that characterize everyday functioning, then there is unlikely to be a clear or meaningful distinction. Inherent and unique to personality disorders is that they concern a person's sense of self and identity. They are disorders of everyday functioning. Personality disorders have an early onset, characterize everyday functioning, and relate closely to personality functioning evident within the general population; Axis I disorders, in contrast, have an onset throughout adult life, are episodic, and are readily distinguishable from normal personality functioning.