Cognitive-Behavioral Therapy for Obsessive–Compulsive Disorder with and without Autism Spectrum Disorder: Gray Matter Differences Associated with Poor Outcome

Abstract

Cognitive behavioral therapy (CBT) is an effective treatment for obsessive–compulsive disorder (OCD) and is also applicable to patients with both OCD and autism spectrum disorder (ASD). However, previous studies have reported that CBT for patients with both OCD and ASD might be less effective than for patients with OCD alone. In addition, there is no evidence as to why autistic traits might be risk factors. Therefore, we investigated whether comorbidity between ASD and OCD may significantly affect treatment outcome and discovered predictors of CBT outcomes using structural magnetic resonance imaging (MRI) data. A total of 39 patients, who were diagnosed with OCD, were enrolled in this study. Of these, except for 2 dropout cases, 15 patients were diagnosed with ASD, and 22 patients were diagnosed with OCD without ASD. Both groups took CBT for 11–20 sessions. First, to examine the effectiveness of CBT for OCD patients with and without ASD, we compared CBT outcomes between the two groups. Second, to investigate how the structural abnormality profile of the brain at pretreatment influenced CBT outcomes, we performed a structural MRI comparison focusing on the gray matter volume of the whole brain in both patients with only OCD, and those with both OCD and ASD. In order to discover neurostructural predictors of CBT outcomes besides autistic traits, we divided our samples again into two groups of those who did and those who did not remit after CBT, and repeated the analysis taking autistic traits into account. The results showed that OCD patients with ASD responded significantly less well to CBT. The OCD patients with ASD had much less gray matter volume in the left occipital lobe than OCD patients without ASD. The non-remission group had a significantly smaller volume of gray matter in the left dorsolateral prefrontal cortex (DLPFC) compared with the remission group, after having partialed out autistic traits. These results indicate that the abnormalities in DLPFC negatively affect the CBT outcome, regardless of the severity of the autistic traits.

The effects of cognitive behavioral therapy on resting‐state functional brain network in drug‐naive patients with obsessive–compulsive disorder

“…CBT treatment helps OCD patients develop more effective cognitive strategies to adapt to their external and changing environment (Moras, 2006). Previous studies have found that the higher rCBF and regional homogeneity in the left DLPFC decreased after CBT treatment (Yamanishi et al, 2009;Yang et al, 2015), and the abnormalities of grey matter volume in DLPFC negatively affected the CBT outcomes (Tsuchiyagaito et al, 2017). The current study's finding that successful CBT treatment decreased the DC in the left DLPFC indicates that the numbers of voxels across the brain that strongly correlate with the left DLPFC decreased, which may be related to the much lower effort required to control intrusive thoughts and repetitive behavior in OCD patients after CBT.…”

Predictors of response to exposure and response prevention for obsessive-compulsive disorder

“…Previous studies have suggested that CBT for obsessive-compulsive disorder with ASD is effective [39], but that the response to ERP is relatively poor [14]. The novelty of this study was that the ability to communicate in AQ predicted treatment response.…”

“…When patients with OCD have poor executive function, they cannot understand their problem or conduct and complete ERP tasks appropriately. A previous brain imaging study showed that abnormalities in the left dorsolateral prefrontal cortex, a region that has been implicated in working memory [43], negatively affect CBT outcomes [14]. Mental flexibility, as measured using the California Verbal Learning Test, was predictive of a good response to CBT; in contrast, it was interesting to note that fluoxetine responsiveness was impaired [44].…”

“…Previous studies have suggested that responses to CBT are diminished among patients whose symptoms overlap with autism spectrum disorder (ASD) criteria [13,14]; treatment resistance may thus be attributable the presentation of ASD characteristics. Moreover, a heightened severity of obsessive-compulsive symptoms at the first clinical visit has been associated with poor prognosis [15], and severe major depressive disorder has been shown to inhibit therapeutic response to CBT [16].…”

Blended cognitive behavioural therapy for adolescents with panic disorder co-morbid with autism spectrum disorder: a case study

“…In addition, a previous randomised controlled trial (RCT) for CBT for co-morbid obsessivecompulsive disorder (OCD) in high-functioning ASD has reported within-group effect sizes of 1.01 for the CBT group (Russell et al, 2013). To summarise the results of previous studies, CBT appears to be effective in treating anxiety in patients with ASD (Perihan et al, 2019;Ung et al, 2015), but less effective in patients without ASD (Tsuchiyagaito et al, 2017).…”