Negative Effects From Psychological Treatments
David H. Barlow
The author offers a 40-year perspective on the observation
and study of negative effects from psychotherapy or psy-
chological treatments. This perspective is placed in the
context of the enormous progress in refining methodologies
for psychotherapy research over that period of time, re-
sulting in the clear demonstration of positive effects from
psychological treatments for many disorders and problems.
The study of negative effects—whether due to techniques,
client variables, therapist variables, or some combination
of these—has not been accorded the same degree of atten-
tion. Indeed, methodologies suitable for ascertaining pos-
itive effects often obscure negative effects in the absence of
specific strategies for explicating these outcomes. Greater
emphasis on more individual idiographic approaches to
studying the effects of psychological interventions would
seem necessary if psychologists are to avoid harming their
patients and if they are to better understand the causes of
negative or iatrogenic effects from their treatment efforts.
This would be best carried out in the context of a strong
collaboration among frontline clinicians and clinical sci-
remains crystal clear. The instructor, with impeccable ac-
ademic credentials and extensive experience in psychother-
apy, announced that we would begin our course of study
with what was then called client-centered therapy. The
reason? With this approach, there would be less chance that
we would actually harm our clients as we began the process
of becoming psychotherapists.1Another mentor in that era,
a psychologist in a respected child clinical center, re-
counted an anecdote of riding the elevator with a child from
the reception area to a treatment room. On the way, the
elevator stopped at an intermediate floor where he was
joined by the parents of the child and their therapist. All
said “hello.” After the session, the psychologist was casti-
gated by the supervising psychiatrist for not timing his ride
better and for the “irreparable harm” caused to therapeutic
relationships by the blurring of professional roles when the
family and the child inadvertently viewed each other with
their therapists. Influential books during this period also
underscored the grave harm that could occur during therapy
Keywords: psychotherapy, psychotherapy research, nega-
tive effects from therapy, idiographic research
took my first psychotherapy course in 1965. Although
the deepening shadows of time have obliterated most
of the content of those early lectures, one admonition
(e.g., Stuart, 1970). Being awakened to the possibility that
one could inflict dire harm on patients during each visit to
the consulting room (or even on the way to it) was an ever
present source of anxiety during those early years for many
of us. However, this anxiety sparked interest in the variety
of ways that both benefit and harm during therapy might
To take one example, one of the clear proscriptions
communicated to all therapists in those early years was to
avoid provoking anything more than mild anxiety in pa-
tients, and the advice had firm theoretical grounding at the
time in both psychoanalytic and behavioral theorizing.
From the psychoanalytic point of view, the dangers of
experiencing intense conflict-driven emotion and the role
of defense mechanisms in preventing this experience were
already widely accepted (Fenichel, 1945). From the behav-
ioral point of view, I had the good fortune in 1966 to study
with Joseph Wolpe, who developed systematic desensiti-
zation to treat anxiety and fear. However, systematic de-
sensitization was designed to work very gradually up a
hierarchy of anxiety and fear on the premise that individ-
uals with fears, phobias, and anxiety could tolerate only
incremental increases in these emotions. According to
Wolpe (1958), more intense experiences might result in the
Pavlovian construct of transmarginal inhibition, or a state
of complete shutdown of the organism. Similar but less
dramatic concerns focused on further sensitizing the indi-
vidual through excessive stimulation (Groves & Thomp-
son, 1970). Thus, from a theoretical point of view, psycho-
analytic and behavioral approaches concurred on the
dangers of experiencing intense emotion without providing
any guidelines on how much emotion was too much. As a
consequence, therapists were very cautious indeed. It
wasn’t until the late 1960s or early 1970s that experimen-
tation with more intensive therapist-guided in vivo expo-
My gratitude goes to Allen Bergin for his comments on an earlier version
of this article, to Anke Ehlers for assembling and reanalyzing some data,
and to Ben Emmert-Aronson for his research and organizational efforts.
Correspondence concerning this article should be addressed to David
H. Barlow, Center for Anxiety and Related Disorders, Boston University,
648 Beacon Street,6thFloor,
1Ironically, Bergin (1963) provided some data indicating that client-
centered therapy was the one therapeutic approach with evidence to
suggest that it might cause deterioration in some clients.
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