1
An Introduction to the Science and Practice of Evidence-Based
Psychotherapy
A Framework for Evaluation and a Way Forward
Daniel David,1 Steven Jay Lynn,2 and Guy H. Montgomery3
' Department of Clinical Psychology and Psychotherapy, Babes-Bolyai University, Cluj-Napoca, Romania
2 Psychology Department, Binghamton University, Binghamton, USA
3 Department of Population Health Science and Policy, Icahn School of Medicine at Mount Sinai, New York, USA

The terrain of contemporary psychotherapy is vast. In fact, patients can choose from
more than 500 brands of psychotherapy. The challenges in navigating this bewildering
landscape of psychotherapeutic interventions can be daunting (Lilienfeld, 2007). In this
volume, we guide consumers of psychotherapy, clinicians, researchers, and students in
the task of ascertaining the psychological treatments that are most rigorously evaluated,
the treatment mechanisms that are best established, and the interventions that are most
likely to be associated with positive outcomes for an array of disorders.

1.1 Evidence-Based Psychotherapies and Clinical Practice
Many psychotherapies in vogue today have never been subjected to rigorous scien-
tific scrutiny, and there is no guarantee that a consumer of psychotherapy will receive
an effective, evidence-based treatment. Although researchers have demonstrated that
some psychotherapeutic interventions are successful, many individuals with major men-
tal disorders still fail to receive treatments grounded in rigorous research (see Lynn &
Lilienfeld, 2017). As Lilienfeld (2007) points out, surveys of clinical practitioners reveal
that "substantial pluralities or even majorities do not treat patients with empirically sup-
ported methods" (p. 63). One such survey (Kessler et al., 2003) revealed that only about
a fifth of individuals with clinical depression received adequate, empirically based clin-
ical treatment in the year in which they were interviewed (see also Wang, Berglund, &
Kessler, 2000, reporting similar findings for anxiety disorders). A more recent represen-
tative community household survey from 21 countries found that, among respondents
who received treatment for depression, only 41% received treatment that met even min-
imal standards (Thornicroft et al., 2017). Most people with depression receive no psy-
chological treatment, grossly suboptimal treatment, or ineffective treatment (Kessler
2

1 An Introduction to the Science and Practice of Evidence-Based Psychotherapy
et al., 2003; Shim, Baltrus, Ye, & Rust, 2011). Much the same can be said for anxious
individuals. In a study of 582 patients with anxiety disorders treated in community
mental health settings, only 13.2% received cognitive-behavioral therapy, an empiri-
cally based treatment for anxiety (Sorsdahl et al., 2013; Wolitzky-Taylor, Zimmerman,
Arch, De Guzman, & Lagomasino, 2015).
There is reason for equal, if not more, pessimism regarding treatment of disorders
other than anxiety and depression. About one-third of individuals with autism receive
nonvalidated interventions (Romanczyk, Turner, Sevlever, & Gillis, 2015); the major-
ity of therapists who treat posttraumatic stress disorder fail to implement exposure
and response prevention, one of the consensus treatments of choice for this condition
(Freiheit, Vye, Swan, & Cady, 2004; Lilienfeld, 2007; Russell & Silver, 2007; see also Chap-
ter 7); most therapists who treat eating disorders fail to capitalize on scientifically based
treatments (Lilienfeld, Ritschel, Lynn, Brown et al., 2013); and as many as three-quarters
of licensed social workers deliver one or more interventions with no research grounding
whatsoever (Pignotti & Thyer, 2009).
Other interventions (e.g., attachment therapies, memory recovery techniques, critical
incident stress debriefing, grief counseling for normal bereavement) not only lack empir-
ical support but are also potentially harmful. Several produce "deterioration effects" in
as many as 3% to 10% of patients, in which patients become worse after psychotherapy
(see Lilienfeld, 2007). Moreover, a quarter or more of therapists report they use highly
suggestive techniques (such as guided imagery or repeated prompting of memories) that
are known to increase the risk of false memories of abuse (see Lynn, Krackow, Loftus,
Locke, & Lilienfeld, 2015). Thomas Insel, the director of the National Institute of Mental
Health, framed the situation this way: "Mental health care in America is ailing" (Insel &
Fenton, 2009).
Unfortunately, many mental health professionals administer scientifically question-
able or pseudoscientific techniques (see Lilienfeld, Lynn, & Lohr, 2015). For example,
a large national survey by Kessler and associates (2001) revealed that substantial num-
bers of clinically depressed and anxious individuals receive such interventions as "energy
therapy," massage therapy, aromatherapy, acupuncture, and even laughter therapy (see
also Lee & Hunsley, 2015; Lilienfeld et al., 2015; Lilienfeld, Ruscio, & Lynn, 2008). Even if
treatments such as equine assisted therapy (i.e., animal-assisted therapy), which lack rig-
orous empirical support (Anestis, Anestis, Zawilinski, Hopkins, & Lilienfeld, 2014), do
little or no harm, mental health consumers who engage in them may forego effective
interventions. Economists term this little-appreciated adverse effect an "opportunity
cost." Such unsupported techniques also deprive mental health consumers of valuable
time, money, and energy, sometimes leaving them with precious little of all three (see
Lynn & Lilienfeld, 2017; Lynn, Malakataris, Condon, Maxwell, & Cleere, 2012). Non-
scientific practices can also tarnish the reputation and credibility of mental health pro-
fessionals, rendering members of the general public more reluctant to turn to them for
greatly needed psychological help (Lynn & Lilienfeld, 2017).
In the main, psychotherapy is helpful. Scientists have established that many
interventions-those that focus on directly changing people's thoughts, feelings, behav-
iors, and interpersonal relationships-are superior to no therapy, and often work as
well as, or even better than, medications for common psychological conditions such
as depression and anxiety (Barlow, Gorman, Shear, & Woods, 2000; Butler, Chapman,
Forman, & Beck, 2006; Dimidjian et al., 2006; Lemmens et al., 2015; Stewart & Chamb-
less, 2009; Weitz et al., 2015). Moreover, psychotherapy combined with medication pro-
duces better outcomes in the treatment of depression than medication alone (Cuijpers,
De Wit, Weitz, Andersson, & Huibers, 2015).
Still, implementing interventions, maximizing their outcomes, and getting them
to patients in need are by no means without challenges. Although evidence-based
therapies are available for a diversity of clinical conditions, there exists a pressing
need to more widely disseminate (by teaching, training, and practice) and increase
the accessibility of such services (Barnett, Rosenberg, Rosenberg, Osofsky, & Wolford,
2014; Karlin & Cross, 2014; Stewart et al., 2014). For example, as many as 70% of
individuals with anxiety and mood disorders do not use or have access to psychological
services (Kazdin & Rabbitt, 2013; Lilienfeld, Lynn, & Namy, 2018). Moreover, there
is much room for improvements in evidence-based therapies, as many patients with
clinical conditions do not respond satisfactorily to treatment, and, even when they do
respond, they often relapse months to years after treatment (Steinert, Hofmann, Kruse,
& Leichsenring, 2014).

1.2 Classifying Psychotherapies: Tricky Business
As David and Montgomery (2011) argued, the meaning of the term "evidence-based
psychotherapy" is a moving target that varies considerably among (a) researchers, (b)
classification schemes that identify therapies as "empirically supported," and (c) inter-
national organizations. A particular therapy may be considered empirically supported
vis-à-vis one classification system, yet not be listed as supported in another classifica-
tion system. Indeed, multiple evaluative frameworks for evidence-based psychothera-
pies have generated conflicting views and diverging standards regarding the status of
individual psychological interventions. For example, the National Institute for Health
and Care Excellence's guidelines (http://www.nice.org.uk) are not always consistent with
those stipulated by Division 12 (the Society of Clinical Psychology) of the American Psy-
chological Association (https://www.div12.org/psychological-treatments) or the Amer-
ican Psychiatric Association (http://www.psych.org), or with the conclusions of typically
comprehensive Cochrane Reviews (http://www.cochrane.org). This lack of consistency
instills confusion among professionals and patients alike, both of whom are seeking to
select empirically validated treatments, and strongly supports the need for a unified,
more scientifically oriented system for categorizing psychological treatments.
Most of the abovementioned classification systems are limited to a focus on the
empirical status of the therapy package. Typically, the schemes evaluate the intervention
package by comparing it with various control conditions (e.g., no intervention, wait-
list, placebo/attention control, treatment as usual, active treatment, evidence-based
treatment). Nevertheless, a treatment package is typically allied with a hypothe-
sized underlying theory/mechanism of change, which should, we contend, impact
the evidence-based status of the treatment delivered. Unfortunately, as David and
Montgomery (2011) have argued, the current evaluative psychotherapy frameworks
ignore the support, or lack thereof, for underlying theory and mechanism of change.
Conceivably, a technique based on voodoo practices could be classified as "probably
1.4 What We Aim to Accomplish
Our book presents the most systematic evaluation of psychotherapies for a variety of
psychological disorders. The structure relies heavily on the David and Montgomery
(2011) framework for evaluating the state of the science of psychotherapy interventions.
More specifically, we have engaged eminent experts to evaluate the scientific status of
psychotherapy for each disorder presented in the pages that follow. The new frame-
work is used as a springboard to consider both theory (i.e., mechanisms of psychologi-
cal change) and the therapeutic package. Contributors evaluate therapies in terms of the
extent to which interventions and theoretical mechanisms are supported by empirical
evidence ranging from empirically well-supported to contradictory evidence. Although
the framework uses categories, with well described criteria for placement in each cate-
gory (e.g., minimum number of positive trials), to describe the empirical status of stud-
ies pertinent to different disorders, the chapter authors do consider the entire body of
evidence related to the therapies they describe and address the strengths and weak-
nesses of the research base in doing so (e.g., through the use of the "mixed data" status).
This scheme affords researchers, clinicians, patients, and students the opportunity to
assess the empirical status of treatments for disorders likely to be encountered in clin-
ical practice and to separate science-based treatments from primarily pseudoscientific
interventions.
To facilitate comparisons across disorders and therapies, and to move the field of psy-
chotherapy forward, we invited experts to present (1) a description of the disorder (e.g.,
diagnostic features, prevalence); (2) a review of empirical support for the intervention
and the supporting theory; and (3) implications for research and practice. The chapters
encompass adult and child treatments and family and couples interventions. Our aim
was to catalogue studies that support or fail to support treatment efficacy and effective-
ness and to assess whether the psychological mechanisms presumed to be associated
with therapeutic change are, in fact, supported by empirical studies. Typically, the term
"efficacy" refers to studies with maximum internal validity (e.g., an RCT with a well-
described treatment protocol and highly trained therapists), whereas the term "effec-
tiveness" refers to studies that evaluate how well an intervention works in the real world
or everyday practice. Nevertheless, in this volume, the terms are often used interchange-
ably by the authors so the exact meaning should be determined in each context. Taking
into account our classification scheme, which is based on randomized trials, typically
the focus is on efficacy studies, without ignoring existing effectiveness studies.

1.5 Conclusions
In conclusion, the authors of the chapters in this book evaluate the evidentiary status of
treatments for a specific disorder or condition in terms of a well-delineated framework.
By providing an up-to-date snapshot of the field of psychotherapy and pinpointing gaps
in our knowledge of the efficacy and effectiveness of diverse interventions, each chapter
provides researchers with potential directions for future studies.
Surveys consistently reveal that many clinicians do not embrace empirically sup-
ported psychotherapies, despite clear indications of their superiority over interventions
that might be appealing on face yet have little or no scientific standing (Lilienfeld,
Ritschel, Lynn, Cautin, & Latzman, 2013). Accordingly, an overarching goal of this book
is to tout the promise of empirically based methods and to increase the accessibility
of the very best practices available for psychological disorders and conditions (ranging
from insomnia to schizophrenia) and broadly promote their dissemination.
Readers will come to appreciate that the empirical support for theory and treatment
protocols varies greatly, and that some treatments are considerably more efficacious
or effective than others within and across the psychological disorders and conditions
reviewed. We hope that our book will serve as an invaluable resource for the broad
range of consumers (or potential consumers) of psychological services who wish to make
informed choices regarding the most efficacious treatments for their problems in living
and the psychological challenges their loved ones face.

References
Anestis, M. D., Anestis, J. C., Zawilinski, L. L., Hopkins, T. A., & Lilienfeld, S. O. (2014).
Equine-related treatments for mental disorders lack empirical support: A systematic
review of empirical investigations. Journal of Clinical Psychology, 70(12), 1115-1132.
doi:10.1002/jclp.22113
Barlow, D. H., Gorman, J. M., Shear, M. K., & Woods, S. W. (2000). Cognitive-behavioral
therapy, imipramine, or their combination for panic disorder: A randomized controlled
trial. JAMA, 283(19), 2529-2536. doi:10.1001/jama.283.19.2529
Barnett, E. R., Rosenberg, H. J., Rosenberg, S. D., Osofsky, J. D., & Wolford, G. L. (2014).
Innovations in practice: Dissemination and implementation of child-parent
psychotherapy in rural public health agencies. Child and Adolescent Mental Health,
19(3), 215-218. doi:10.1111/camh.12041
Butler, A. C., Chapman, J. E., Forman, E. M., & Beck, A. T. (2006). The empirical status of
cognitive-behavioral therapy: A review of meta-analyses. Clinical Psychology Review,
26(1), 17-31. doi:10.1016/j.cpr.2005.07.003
Cuijpers, P., De Wit, L., Weitz, E., Andersson, G., & Huibers, M. J. (2015). The combination
of psychotherapy and pharmacotherapy in the treatment of adult depression: A
comprehensive meta-analysis. Journal of Evidence-Based Psychotherapies, 15(2),
147-168.
David, D., & Montgomery, G. (2011). The scientific status of psychotherapies: A new
evaluative framework for evidence-based psychosocial interventions. Clinical
Psychology: Science and Practice, 18, 88-99. doi:10.1111/j.1468-2850.2011.01239.x
DiGiuseppe, R., David, X., & Venezia, R. (2016). Cognitive theories. In J. C. Norcross, G. R.
VandenBos, D. K. Freedheim, & B. O. Olatunji (Eds.), APA handbook of clinical
psychology: Theory and research (Vol. 2, pp. 154-182). Washington, DC: American
Psychological Association.
Dimidjian, S., Hollon, S. D., Dobson, K. S., Schmaling, K. B., Kohlenberg, R. J., Addis, M.
E., ... Atkins, D. C. (2006). Randomized trial of behavioral activation, cognitive therapy,
and antidepressant medication in the acute treatment of adults with major depression.
Journal of Consulting and Clinical Psychology, 74(4), 658-670. doi:10.1037/0022-006x.
74.4.658
Freiheit, S. R., Vye, C., Swan, R., & Cady, M. (2004). Cognitive-behavioral therapy for
anxiety: Is dissemination working? Behavior Therapist, 27(2), 25-32.
Insel, T. R., & Fenton, W. S. (2005). Psychiatric epidemiology: It's not just about counting.
Archives of General Psychiatry, 62(6), 590-592.
Karlin, B. E., & Cross, G. (2014). From the laboratory to the therapy room: National
dissemination and implementation of evidence-based psychotherapies in the US
Department of Veterans Affairs Health Care System. American Psychologist, 69(1),
19-33. doi:10.1037/a0033888
Kazdin, A. E., & Rabbitt, S. M. (2013). Novel models for delivering mental health services
and reducing the burdens of mental illness. Clinical Psychological Science, 1(2), 170-191.
doi:10.1177/2167702612463566
Kessler, R. C., Berglund, P., Demier, O., Jin, R., Koretz, D., Merikangas, K. R., ... Wang, P. S.
(2003). The epidemiology of major depressive disorder: Results from the National
Comorbidity Survey Replication (NCS-R). JAMA, 289(23), 3095-3105. doi:10.1001/
jama.289.23.3095
Kessler, R. C., Soukup, J., Davis, R. B., Foster, D. F., Wilkey, S. A., Van Rompay, M. I., &
Eisenberg, D. M. (2001). The use of complementary and alternative therapies to treat
anxiety and depression in the United States. American Journal of Psychiatry, 158(2),
289-294. doi:10.1176/appi.ajp.158.2.289
Kuhn, T. S. (1962). The structure of scientific revolutions. Chicago, IL: University of Chicago
Press.
Lee, C. M., & Hunsley, J. (2015). Evidence-based practice: Separating science from
pseudoscience. Canadian Journal of Psychiatry, 60(12), 534-540. doi:10.1177/
070674371506001203
Lemmens, L. H. J. M., Arntz, A., Peeters, F. P. M. L., Hollon, S. D., Roefs, A., & Huibers,
M. J. H. (2015). Clinical effectiveness of cognitive therapy v. interpersonal psychotherapy
for depression: Results of a randomized controlled trial. Psychological Medicine, 45(10),
2095-2110. doi:10.1017/s0033291715000033
Lilienfeld, S. O. (2007). Psychological treatments that cause harm. Perspectives on
Psychological Science, 2(1), 53-70. doi:10.1111/j.1745-6916.2007.00029.x
Lilienfeld, S. O., Lynn, S. J., & Lohr, J. (Eds.). (2015). Science and pseudoscience in clinical
psychology (2nd ed.). New York, NY: Guilford Press.
Lilienfeld, S. O., Lynn, S. J., & Namy, L. (2018). Psychology: From inquiry to understanding
(4th ed.). New York, NY: Pearson.
Lilienfeld, S. O., Ritschel, L. A., Lynn, S. J., Brown, A. P., Cautin, R. L., & Latzman, R. D.
(2013). The research-practice gap: Bridging the schism between eating disorder
researchers and practitioners. International Journal of Eating Disorders, 46(5), 386-394.
doi:10.1002/eat.22090
Lilienfeld, S. O., Ritschel, L. A., Lynn, S. J., Cautin, R. L., & Latzman, R. D. (2013). Why
many clinical psychologists are resistant to evidence-based practice: Root causes and
constructive remedies. Clinical Psychology Review, 33(7), 883-900. doi:10.1016/j.cpr.
2012.09.008
Lilienfeld, S. O., Ritschel, L. A., Lynn, S. J., Cautin, R. L., & Latzman, R. D. (2014). Why
ineffective psychotherapies appear to work: A taxonomy of causes of spurious
therapeutic effectiveness. Perspectives on Psychological Science, 9(4), 355-387.
doi:10.1177/1745691614535216
Books.
Lynn, S. J., Krackow, E., Loftus, E. F., Locke, T. J., & Lilienfeld, S. O. (2015). The
remembrance of things past: Problematic memory recovery techniques in
psychotherapy. In S. O. Lilienfeld, S. J. Lynn, & J. Lohr (Eds.), Science and pseudoscience
in clinical psychology (2nd ed., pp. 205-242). New York, NY: Guilford Press.
Lynn, S. J., & Lilienfeld, S. O. (2017). Off the rails: Psychotherapy gone wrong and the road to
evidence-based treatment. Unpublished manuscript.
Lynn, S. J., Malakataris, A., Condon, L., Maxwell, R., & Cleere, C. (2012). The treatment of
posttraumatic stress disorder: Cognitive hypnotherapy, mindfulness, and
acceptance-based approaches. American Journal of Clinical Hypnosis, 54(4), 311-330.
doi:10.1080/00029157.2011.645913
Pignotti, M., & Thyer, B. A. (2009). Use of novel unsupported and empirically supported
therapies by licensed clinical social workers: An exploratory study. Social Work Research,
33(1), 5-17. doi:10.1093/swr/33.1.5
Romanczyk, R. G., Turner, L. B., Sevlever, M., & Gillis, J. (2015). The status of treatment for
autism spectrum disorders: The weak relationship of science to interventions. In S. O.
Lilienfeld, S. J. Lynn, & J. M. Lohr (Eds.), Science and pseudoscience in contemporary
clinical psychology (pp. 431-465). New York, NY: Guilford Press.
Rush, A. J., Beck, A. T., Kovacs, M., & Hollon, S. (1977). Comparative efficacy of cognitive
therapy and pharmacotherapy in the treatment of depressed outpatients. Cognitive
Therapy and Research, 1(1), 17-37. doi:10.1007/BF01173502
Russell, M., & Silver, S. M. (2007). Training needs for the treatment of combat-related
posttraumatic stress disorder: A survey of Department of Defense clinicians.
Traumatology, 13, 4-10. doi:10.1177/1534765607305440
Shim, R. S., Baltrus, P., Ye, J., & Rust, G. (2011). Prevalence, treatment, and control of
depressive symptoms in the United States: Results from the National Health and
Nutrition Examination Survey (NHANES), 2005-2008. Journal of the American Board of
Family Medicine, 24(1), 33-38. doi:10.3122/jabfm.2011.01.100121
Sorsdahl, K., Blanco, C., Rae, D. S., Pincus, H., Narrow, W. E., Suliman, S., & Stein, D. J.
(2013). Treatment of anxiety disorders by psychiatrists from the American Psychiatric
Practice Research Network. Revista Brasileira de Psiquiatria, 35(2), 136-141.
doi:10.1590/1516-4446-2012-0978
Steinert, C., Hofmann, M., Kruse, J., & Leichsenring, F. (2014). Relapse rates after
psychotherapy for depression: Stable long-term effects? A meta-analysis. Journal of
Affective Disorders, 168, 107-118. doi:10.1016/j.jad.2014.06.043
Stewart, M. O., Raffa, S. D., Steele, J. L., Miller, S. A., Clougherty, K. F., Hinrichsen, G. A., &
Karlin, B. E. (2014). National dissemination of interpersonal psychotherapy for
depression in veterans: Therapist and patient-level outcomes. Journal of Consulting and
Clinical Psychology, 82(6), 1201-1206. doi:10.1037/a0037410
Stewart, R. E., & Chambless, D. L. (2009). Cognitive-behavioral therapy for adult anxiety
disorders in clinical practice: A meta-analysis of effectiveness studies. Journal of
Consulting and Clinical Psychology, 77(4), 595-606. doi:10.1037/a0016032
Thornicroft, G., Chatterji, S., Evans-Lacko, S., Gruber, M., Sampson, N., Aguilar-Gaxiola,
S., ... Bruffaerts, R. (2017). Undertreatment of people with major depressive disorder in

Lilienfeld, S. O., Ruscio, J., & Lynn, S. J. (Eds.). (2008). Navigating the mindfield: A guide to
separating science from pseudoscience in mental health. Amherst, NY: Prometheus
188078
Wang, P. S., Berglund, P., & Kessler, R. C. (2000). Recent care of common mental disorders
in the United States. Journal of General Internal Medicine, 15(5), 284-292. doi:10.1046/
j.1525-1497.2000.9908044.x
Weitz, E. S., Hollon, S. D., Twisk, J., Van Straten, A., Huibers, M. J., David, D., ... Faramarzi,
M. (2015). Baseline depression severity as moderator of depression outcomes between
cognitive behavioral therapy vs pharmacotherapy: An individual patient data meta-
analysis. JAMA Psychiatry, 72(11), 1102-1109. doi:10.1001/jamapsychiatry.2015.1516
Wolitzky-Taylor, K., Zimmermann, M., Arch, J. J., De Guzman, E., & Lagomasino, I. (2015).
Has evidence-based psychosocial treatment for anxiety disorders permeated usual care
in community mental health settings? Behaviour Research and Therapy, 72, 9-17.
doi:10.1016/j.brat.2015.06.010

21 countries. British Journal of Psychiatry, 210(2), 119-124. doi:10.1192/bjp.bp.116.