Personality disorder not otherwise specified (PD-NOS) is a subclinical[a] diagnostic classification for some DSM-IV Axis II personality disorders not listed in DSM-IV.
Clinicians may give this diagnosis when no other personality disorder in the DSM fits the patient's symptoms.
The closest diagnosis to PD-NOS would be Personality disorder, severity unspecified (6D10.Z).
The National Comorbidity Survey Replication estimated the prevalence of PD-NOS in the general population at around 1.6% (0.3-2.9%).
Half the studies did not give further definition for the diagnosis, and those that did used "mixed" most often.