 35. Personality and Psychopathology  749
iors that integrate personality concepts in 
a meaningful and substantive way. For ex -
ample, researchers examining the develop -
ment of externalizing psychopathology in 
youth have noted that many of these behav -
iors onset or peak in adolescence (e.g., de -
linquency, addictive behaviors, risky sexual 
behavior; Burt, 2012; Stanger, Achenbach, 
& Verhulst, 1997). More recent theories of 
adolescent risky behaviors (including disin -
hibitory psychopathology), invoke develop -
mental increases in sensation-  seeking and 
reward sensitivity in combination with lower 
levels of self-  control (all personality traits) as 
potential mechanisms underlying these de -
velopmental trends (Steinberg, 2008).
Personality can easily be integrated into 
a broader developmental psychopathol -
ogy framework that emphasizes concepts 
of multifinality and equifinality, delineating 
mechanisms leading to change and conti -
nuity over time, and examining the role of 
development in psychopathology (Rutter 
& Sroufe, 2000). The concepts of multifi -
nality  (when the same risk factor results in 
multiple and distinct outcomes) and equi-
finality  (when different risk factors results 
in the same outcome) are commonly inves -
tigated as developmental causal processes 
for psychopathology. These processes can 
be readily integrated with the vulnerability 
model, described previously, when consid -
ering early personality traits as risk factors 
for later psychopathology. For example, be -
havioral inhibition—  a temperamental risk 
factor for later anxiety disorders—  is mod -
erated by social involvement in adolescence 
(Frenkel et al., 2015), a finding consistent 
with a multifinality process in personality– 
psychopathology associations.
Clinical Utility and  Applications
Despite the research examining the intersec -
tion of personality and psychopathology, 
the use of personality is quite limited with -
in clinical settings. While the trait-based 
personality literature has a rich supply of 
empirical scholarship demonstrating clear 
links between personality traits and psy -
chopathology, it has been argued that this 
literature is difficult to generalize to clinical 
settings (Lengel, Helle, DeShong, Meyer, & 
Mullins-  Sweatt, 2016). We argue that this intersection has vast implications for clinical 
application.
Significance of Personality in Aspects of Living
Personality measurement is a valuable clini -
cal assessment and intervention tool. Traits 
are meaningfully associated with clinically 
relevant personal, social, and occupational 
problems in living (Hopwood et al., 2009; 
Mullins-  Sweatt & Widiger, 2010; Ozer & 
Benet-  Martinez, 2006). Additionally, they 
are related to maladaptive behaviors such as 
nonsuicidal self-  injury (NSSI; Brown, 2009; 
Glenn & Klonsky, 2010), relational aggres -
sion (Atherton, Tackett, Ferrer, & Robins, 
2017), alcohol abuse (Turiano, Whiteman, 
Hampson, Roberts, & Mroczek, 2012), 
pathological gambling (Ledgerwood, Alessi, 
Phoenix, & Petry, 2009), mood and anxiety 
disorders (Clark, Watson, & Mineka, 1994), 
and personality disorders (PDs; Widiger & 
Oltmanns, Chapter 36, this volume). Final -
ly, traits may contribute to how clinicians se -
lect appropriate treatments, provide realistic 
progress expectations (e.g., which behaviors 
are amenable to change), and help improve a 
client’s sense of self (Harkness & Lilienfeld, 
1997).
Personality traits are associated with a 
variety of physical and mental health out -
comes, as well as aspects of daily living. 
For example, Malouff, Thorsteinsson, and 
Schutte (2005) found that mental disorders 
are associated with high levels of neuroti -
cism and low levels of conscientiousness, ex -
traversion, and agreeableness. Neuroticism 
appears to relate most highly with several 
clinical disorders and maladaptive behav -
iors, and seems to be the primary trait that 
distinguishes between individuals with and 
without psychopathology (Krueger, Caspi, 
Moffitt, Silva, & McGee, 1996). Broadly, 
mood, anxiety, and substance abuse are 
associated with high neuroticism and low 
conscientiousness, while, more specifically, 
dysthymic disorder and social phobia are as -
sociated with low extraversion (Kotov et al., 
2010).
Personality traits are also linked to a va -
riety of clinically relevant physical health 
outcomes as well. For example, extraversion 
and conscientiousness are correlated with 
longevity (e.g., Danner, Snowdon, & Fries -