By: MARY ANN MOON, Clinical Psychiatry News Digital Network
Schizophrenia with comorbid panic disorder, also
known as panic psychosis, appears to be a distinct subtype of
schizophrenia, according to a study published in Psychiatry Research.
Patients who have these two psychiatric disorders
concomitantly show distinctive cognitive and neuropsychological
features, and likely will prove to have a different prognosis and a
different biology from that of other patients with schizophrenia, said
Dr. Erica Kirsten Rapp of the Mount Sinai School of Medicine, New York,
and her associates.
Panic attacks have been reported in 7.1%-47.5% of
patients with schizophrenia, depending on the population surveyed and
the techniques used to assess them. Similarly, panic disorder has been
reported in 4.2%-35%.
In research a decade ago, patients who had comorbid
obsessive-compulsive disorder and schizophrenia appeared to have "a
distinct set of clinical symptoms, neuropsychological features, and
treatment responses, prompting researchers to suggest the existence of a
‘schizo-obsessive disorder.’ " To assess whether those with comorbid
panic disorder and schizophrenia constitute a similar subtype, Dr. Rapp
and her colleagues examined 255 inpatients using an extensive battery of
cognitive and neuropsychological tests.
In all, 165 of these study subjects were diagnosed
as having either schizophrenia or schizoaffective disorder without any
accompanying anxiety (the schizophrenia-only group), whereas 39 had
comorbid panic disorder (the panic-schizophrenia group) and 51 had a
nonpanic anxiety disorder (anxiety-schizophrenia group).
Previous investigators have found higher rates of
paranoid schizophrenia among patients with comorbid panic symptoms, so
Dr. Rapp and her associates specifically examined the prevalence of
paranoia in their study subjects. This prevalence was comparable among
the three study groups, with 33.9% of the schizophrenia-only group,
33.3% of the panic-schizophrenia group, and 27.5% of the
anxiety-schizophrenia group having paranoia.
Thus, the study findings would not be confounded by a predominance of paranoia in any of the study groups.
The panic-schizophrenia group differed significantly
from the schizophrenia-only group in numerous measures. They showed
significantly higher IQs, higher verbal IQs, better recall after a
delay, more efficient problem-solving and set-switching abilities,
better attentional skills, and better verbal fluency. They also
performed better than the anxiety-schizophrenia group in
problem-solving, attentional skills, and verbal fluency.
"These results suggest that patients with panic and
schizophrenia may be more cognitively intact . . . and are less likely
to exhibit the level of deficits in executive functioning and overall
intelligence that are often considered to be a core feature of
schizophrenia," Dr. Rapp and her colleagues said (Psychiatr. Res. 2012 [doi:10.1016/j.psychres.2012.01.017]).
"It is likely that both the presence of panic
symptoms and the better neuropsychological performance are precipitated
by [the same] underlying neurobiological factor," they added.
One possible candidate for this underlying factor is
dopamine, which is known to affect executive functioning, positive
symptoms in schizophrenia, and panic symptoms.
The panic-schizophrenia group also reported
significantly more dysthymia when they were stabilized on medication
than did either of the other study groups. This might be related to the
fact that they also demonstrated significantly more insight into their
illness than did the other patients, a finding that has been reported
previously.
Given the superior cognitive performance and
relatively intact executive functioning of the panic-schizophrenia
group, this superior insight might indicate "a better capacity for
metacognition and self-reflection. ... It may be that once their acute
psychoses had resolved, they were more dysphoric about their experiences
and prognosis," the researchers said. Still, their research contributes
to the theory that patients with panic psychosis might "constitute a
distinct group within those with schizophrenia."
This study was supported by the National Institute of Mental Health. No financial conflicts of interest were reported.
No comments:
Post a Comment