I'm serching for the co-morbidity of personality disorders. All say "often" but little numbers. I did get the number 80% when referring to Borderlines.
Here is a source that says 66% of any PD with any PD
http://www.psybc.com/pdfs/library/DepPersDisorder_Co_Morbidity.pdfOne clear problem is the high degree of overlap between the frequency of
DPD and main text PD diagnoses (see Table 1). For example, McDermut et
al. (2003) reported that of those individuals who met criteria forDPD according
to the Structured Interview for DSM–IV Personality Disorders (Pfohl,
Blum,&Zimmerman, 1997), 66% also met criteria for another PD. The highest
rates of comorbidity were for avoidant (43%), borderline (22%), obsessive–
compulsive (21%), and paranoid (16%). All other disorders had overlap
rates of less than 10%. Similarly, using DSM–III–R (APA, 1987) criteria for
PDs, assessed with the Personality Disorder Examination (PDE; Loranger,
1988) and Akiskal’s (1983) criteria for DPD, Klein and Shih (1998) reported
that 58% of individuals who met this criteria for DPD also met criteria for another
PD. Borderline (26%), avoidant (20%), histrionic (17%), and paranoid
(16%) had the highest rates of comorbidity. All other PDs had overlap rates
less than 6%. Although the individual overlap rates of DSM main text PDs
with DPD are not excessive, the overall rate of overlap is large and suggests
that the addition of DPD may exacerbate existing difficulties associated with
the high comorbidity rates among main text PDs.
Most people with PD's have many symptoms from a range of different PDs, and there is often a primary and secondary diagnoses. Some are very similar and are 'clustered' together. Borderlines often have Histrionic features, Scitzoypial are often Paranoid, etc. And very very few people have all the symptoms of something. There are a lot of "subtypes" and mixtures that are recognized by Theodore Million . A particular interesting person is the passive-agressive, borderline-avoidant
Here some quack explains it.
To answer your first question, it is appropriate to diagnose each personality disorder type separately if sufficient criteria are met for each of them to support the diagnosis. For instance, if full criteria were met for each personality disorder you've listed, you would just diagnose the personality disorders you've listed. I've also seen some clinicians make a diagnosis of Mixed Personality Disorder with X, Y and Z traits although this is not strictly by the (DSM-IV) book. If some criteria are met in each area, but not enough in any one of them to make a formal and supportable diagnosis in that area, the appropriate diagnosis is Personality Disorder NOS (not otherwise specified) with X, Y, and Z (or whatever) traits).
