Table 1: Research evidence on the treatment of APD. Prevalence and comorbidity.

Article	Kind of study	Sample	Result	Limits	APD without SP*
Skodol et al. [6]	Clinical based, epidemiological study, follow up of 2 years	600 patients with PD or MDD and no PD followed for at period of to years. APD n = 137.	Symptoms of PD remain stable over time, APD patients had better outcome regarding employment function but a worse result regarding social relationships, but not social functioning.	Positive association bias in assessing relationship quality (< % of PD was in a relationship at the beginning of the study). Limited follow up period for testing changes in PD.	Yes
Zimmerman et al. [12]	Community based, epidemiological study	859 Psychiatric outpatients	1/3 of the enrolled patients had a PD. APD had the higher % of being diagnosed as a single PD (58.7%) along with the HPD (66.7%) APD had also high OR of comorbid PD with cluster A and cluster B PD APD had a significant association with a diagnosis of MDD, GAD and Panic Disorder (~ 20 - 25% of co-diagnosis)	The study was conducted in a private practice group that does not target patients without a health insurance and lower-income patients. No follow-up.	Yes
Asarnow et al. [14]	Community and clinical based epidemiological study	Probands of childhood onset schizophrenia (n = 148), relatives of ADHD patients (n = 368) and community controls (n = 206)	Risk of APD was higher in COS probands (9.41%) vs. controls (1.67%)	Large confidential intervals are reported	No
Reichborn-Kjennerud et al. [15]	Population based epidemiological study	Adult female-female twin pairs. 1427 pairs (898 monozygotic and 529 dizygotic) were included in the analysis and had valid data	The prevalence of APD was 2.7%. 32.5% of subjects with APD also had PD 30.6% of subjects with generalized social phobia also had APD 18.3% of subjects with PD also had APD	Based on females twins only	Yes
Cox et al. [16]	Epidemiological investigation based on a previous survey on Alcohol and Related Conditions	34905 individuals representing the general population in 50 United States	Lifetime prevalence of APD = 2.4% Lifetime prevalence of SP = 2.8% 36.4% of individuals with SP had also APD	The survey was not initially focused on personality disorders	Yes
Tillfors et al. [17]	Epidemiologically identified probands of individuals with SP	1000 women and 1000 men randomly sampled in the greated Stockholm area	A 2 to 3 fold increased RR of social anxiety as a function of a positive parental history of SP or APD, alone or in combination Familial aggregation of SP was not modulated by other diagnoses in axis I or II, indicating that SP and AVP may not be separated disorders	Diagnosis was made through a self-questionnaire	Yes
Lampe et al. [18]	Epidemiological study on the general population	10641 individuals enrolled in the Australian National Survey of Mental health and Well Being	APD 12 month prevalence = 1.5% 28.9% of individuals with SP also had APD.	Non specific for APD	No
Lampe et al. [19]	Epidemiological study on the general population	381 individuals enrolled in the Australian National Survey of Mental health and Well Being	APD 12 month prevalence = 2.3%; F:M ratio = 1.5 26% of subjects with SP also had ADP; F:M ratio = 2	Small sample size	Yes
Hummelen et al. [20]	Epidemiological study involving 12 units of the Norwegian network of Psychotherapeutic Day Hospitals	2192 individuals enrolled in the study	39 % had APD, 48% of whom also had SP	The units that contributed to the enrollment are specialized in personality disorders, this could create a selection bias or over diagnosis of the disorders when compared to the general population.	Yes
Torgersen et al. [98]	Epidemiological study in the general population	2053 individuals from the general population	5% of the population had APD	/	No
Grant et al. [99]	Epidemiological study in the general population	43093 respondents in the National Institute on Alcohol Abuse and Acloholism's 2001-2002 National Epidemiologic Survey on Alchol and Related Conditions	2.4% of the population had APD	Non specific for APD	No