Obsessive– Compulsive Disorder 467
on the negative consequences of suppression. Some studies failed to find any evidence
of immediate enhancement or rebound when OCD samples suppressed their primary
obsession (Janeck & Calamari, 1999; Purdon et al., 2005), whereas Tolin, Abramowitz,
Przeworski, et al. (2002) found an immediate enhancement effect when individuals with
OCD suppressed a neutral thought (i.e., white bears). Based on this finding the authors
suggest that OCD might be characterized by a general inhibitory deficit.
Suppression of unwanted obsessional intrusions in nonclinical samples has also
failed to produce the expected enhancement or resurgence of unwanted thoughts once
suppression efforts cease, although suppression may result in more sustained levels of
unwanted target thought occurrence in the postsuppression period (Belloch, Morillo,
& Giménez, 2004; Hardy & Brewin, 2005; Purdon, 2001; Purdon & Clark, 2001). In
addition failure to completely suppress unwanted target intrusions may have direct or
indirect effects on level of distress associated with recurrence of the unwanted mental
intrusion (Janeck & Calamari, 1999; Purdon & Clark, 2001; Purdon et al., 2005).
Whatever the exact processes involved, the overall findings from the self- report, daily
diary, and experimental studies are consistent with Hypothesis 4 that neutralization
plays an important role in the persistence of obsessional symptoms with particular
effects on the amplification of distress and the misinterpretation of intrusions.
Hypothesis 5
Individuals with OCD are significantly more likely to misinterpret their failure to control
obsessional intrusions as a highly significant threat, whereas individuals without OCD are
more accepting of failed mental control.
Recent experimental research on the suppression of unwanted intrusive thoughts
in both clinical and nonclinical samples indicates that exaggerated misinterpretation of
the significance of failed control might be an important contributor to the pathogenesis
of obsessions. In a reanalysis of their thought suppression experiment, Tolin and col-
leagues found that individuals with OCD reported more internal attributions for their
thought suppression failures than did nonanxious controls (Tolin, Abramowitz, Ham-
lin, et al., 2002b). Purdon et al. (2005) also found that misinterpretation of thought fail-
ures in a thought suppression experiment was the most important predictor of distress
over intrusions and negative mood state. In an earlier nonclinical thought suppression
experiment, exaggerated appraisals of the significance of thought control failures was
associated with a more negative mood state (Purdon, 2001). Furthermore, individuals
who reported a higher need for control exhibited greater thought suppression effort in
the experiment. Magee and Teachman (2007) also found that maladaptive attributions
of self-blame and importance in controlling thoughts predicted distress and recurrence
of unwanted thoughts in a thought suppression experiment. In a recent thought dis-
missal experiment comparing OCD and panic disorder patients, the OCD group had
greater difficulty dismissing their primary obsession than did panic patients their pri-
mary panic- related anxious thought (Purdon, Gifford, & Antony, 2007). Moreover, the
OCD group interpreted their failures in thought control more negatively than the panic
disorder group, but negative appraisals of failed thought control predicted greater dif-
ficulty dismissing the target thought and more negative mood state in both groups. The
authors concluded that deliberate attempts to suppress unwanted thoughts is ill- advised