Personality disorder not otherwise specified

Personality disorder not otherwise specified (also known as Personality disorder NOS or PDNOS) is a DSM-IV Axis II personality disorder.

Diagnostic criteria (DSM-IV-TR = 301.9)
This diagnosis may be given when no other personality disorder defined in the DSM fits the patient's symptoms.

Four personality disorders were excluded from the main body of the latest version of the DSM (DSM-IV-TR) but this diagnosis may be used instead. The four personality disorders are:
 * Sadistic personality disorder
 * Self-defeating personality disorder
 * Depressive personality disorder
 * Passive–aggressive personality disorder

It is a requirement of DSM-IV that a diagnosis of any personality disorder also satisfies a set of general personality disorder criteria.

Diagnostic criteria (ICD-10)
The World Health Organization's ICD-10 defines a conceptually similar disorder to "personality disorder not otherwise specified" called  Personality disorder, unspecified.

It is a requirement of ICD-10 that a diagnosis of any personality disorder also satisfies a set of general personality disorder criteria.

Prevalence (epidemiology)
In one study, PDNOS as found to be the third most frequent personality disorder diagnosis.