 36. Personality and Personality Disorder  759
threshold for a hallucination, odd speech, 
inappropriate or constricted affect, and so -
cial anxiety (American Psychiatric Associa -
tion, 2013).
STPD is not included within the person -
ality disorder section of the WHO (1992) 
ICD-10, and is instead classified as a form 
of schizophrenia. There is compelling em -
pirical support for a genetic association 
of STPD with schizophrenia (Kwapil & 
Barrantes-  Vidal, 2012), which is not surpris -
ing given that the diagnostic criteria were 
obtained from observations of biological rel -
atives of persons with schizophrenia. Many 
of the neurobiological risk factors and psy -
chophysiological correlates of STPD are also 
shared with schizophrenia (e.g., eye track -
ing, orienting, startle blink, and neurodevel -
opmental abnormalities), and the treatments 
that are effective in ameliorating schizotypal 
symptoms overlap with treatments used for 
persons with schizophrenia (Lenzenweger, 
2006). The close relationship of STPD to 
the phenomenology, genetics, and pathol -
ogy of schizophrenia suggests that perhaps 
it should be classified as a variant of schizo -
phrenia rather than a personality disorder 
(Skodol, 2012). In DSM-5, STPD is included 
in both the personality disorders and the 
schizophrenia spectrum sections (American 
Psychiatric Association, 2013). There are, 
however, a number of compelling reasons 
to consider STPD to be a personality disor -
der rather than a variant of schizophrenia. 
STPD is much more comorbid with other 
personality disorders than with psychotic 
disorders, persons with STPD very rarely de -
velop schizophrenia, and schizotypal traits 
are evident within the general population in 
persons with no apparent genetic relation -
ship to schizophrenia (Kwapil & Barrantes- 
Vidal, 2012). The diagnosis of schizophre -
nia has considerable negative connotations, 
and associating STPD with the disorder of 
schizophrenia could be rather stigmatizing 
for the persons who receive the diagnosis.
Dependent Personality  Disorder
Dependent personality disorder (DPD) in -
volves an excessive, clinging attachment to 
others, along with submissiveness and fears 
of separation (American Psychiatric Asso -
ciation, 2013; Bornstein, 2012). Its primary diagnostic criteria include extreme difficul -
ty making decisions, needing others to as -
sume responsibility for daily life, difficulty 
disagreeing with others, inability to initiate 
projects due to lack of self-  confidence, and 
going to excessive lengths to obtain the ap -
proval of others. The diagnosis was slated 
for deletion in DSM-5 (Skodol, 2012), de -
spite there being a considerable body of re -
search to support the validity and clinical 
importance of dependent personality traits 
(Bornstein, 2012; Gore & Pincus, 2013).
Persons with DPD suffer from intense 
feelings of insecurity, fears of abandonment, 
loneliness, helplessness, and fears of nega -
tive evaluation. Dependency is related to 
increased risk for suicide, and excessive use 
of medical and mental health services (Born -
stein, 2012). Dependency is also one of the 
few personality traits with a well-  established 
role in predicting future episodes of depres -
sion. Multiple longitudinal studies have con -
firmed that dependent cognitions and behav -
iors result in depressive episodes in reaction 
to interpersonal loss or rejection (Hammen, 
2005). The self-  esteem of persons with DPD 
depends substantially on the maintenance of 
a nurturant, loving, and secure relationship, 
yet their intense needs for reassurance can 
have the paradoxical effect of driving their 
partner away (Romero-  Canyas, Downey, 
Berenson, Ayduk, & Kang, 2010)
Narcissistic Personality  Disorder
Narcissistic personality disorder (NPD) is 
a pervasive pattern of grandiosity (in fan -
tasy or behavior), need for admiration or 
adulation, and lack of empathy (American 
Psychiatric Association, 2013). Its primary 
diagnostic criteria include a grandiose sense 
of self-  importance; preoccupation with suc -
cess, power, brilliance, or beauty; the belief 
that one is special and can only be under -
stood by high-  status individuals; a demand 
for excessive admiration; and a strong sense 
of entitlement, exploitation of others, lack of 
empathy, and arrogance.
NPD was a new addition to DSM-III 
(American Psychiatric Association, 1980). 
NPD was not included in the subsequently 
developed ICD-10 (WHO, 1992) despite its 
presence in the DSM since 1980, as it has 
been perceived internationally as largely an 