Sammendrag
Background: Obsessive-compulsive disorder (OCD) has been related to worse
performance, abnormal brain activity, and functional connectivity during response
inhibition. Whether these findings are indications of stable traits that contribute to the
development of the disorder, or whether they are a result of the state severity of
obsessions and anxiety, remains unclear since previous research mainly has employed
cross-sectional designs. The present study aimed to assess longitudinal between- and
within-person relationships between symptoms, task performance, right inferior frontal
gyrus brain activation, and connectivity between the right amygdala and the right
pre-supplementary motor area in 29 OCD patients before and after concentrated
exposure and response prevention treatment.
Method: Patients received exposure and response prevention delivered during 4
consecutive days, following the Bergen 4-day Treatment format. Patients performed
a Stop Signal Task during 3T functional Magnetic Resonance Imaging the day before
treatment, as well as 1 week and 3 months after treatment completion. Multilevel models
were used to analyze disaggregated within- and between-person effects over time.
Independent variables were scores on the symptom severity scales for OCD, anxiety,
depression, and state distress during scanning. Dependent variables were reaction time
for go trials, stop signal response time, task-related brain activation and connectivity.
Results: A positive between-person effect was found for obsessive-compulsive,
anxiety, and depressive symptom severity on go trial reaction time, indicating
that patients with higher symptom scores on average respond slower during
accurate go trials. We also found no significant between- or within-person relations
between symptom severity and task-related activation or fronto-limbic connectivity.
Conclusions: The between-person findings may point toward a general association
between slower processing speed and symptom severity in OCD. Longitudinal studies
should disaggregate between- and within-person effects to better understand variation
over time.
Keywords: obsessive-compulsive disorder, response inhibition, stop signal task, functional magnetic resonance
imaging, Bergen 4-day treatment, multilevel modeling
Vis fullstendig beskrivelse
