Neuroanatomic Comparison of Bipolar Adolescents With and Without Cannabis Use Disorders

Abstract

Objective Co-occurrence of substance use and bipolar disorders is both common and associated with poor treatment response and greater functional impairment than either disorder alone. The neurophysiological correlates of this co-morbidity however, remain unclear. In this pilot study, we compared brain morphometry between bipolar adolescents with co-occurring cannabis use disorders (CUD) and bipolar adolescents without any substance use disorder. Methods Whole-brain structural magnetic resonance imaging (MRI) scans were obtained from 14 bipolar adolescents. Seven study participants were diagnosed with CUD before and/or shortly after their MR scan was obtained, and 7 subjects were free of any substance use disorder at the time of their MR scan as well as during longitudinal follow up. Morphologic differences were calculated using voxel-based morphometry implemented using statistical parametric mapping software (SPM2). Results Bipolar adolescents with co-occurring CUD demonstrated decreased gray matter volume (GMV) in the left fusiform gyrus and increased GMV in the right caudate and precentral gyrus, as well as increased gray matter density in the right middle occipital and fusiform gyri and cerebellar vermis. Conclusions Bipolar adolescents with CUD demonstrate evidence of greater structural abnormalities than adolescents with bipolar disorder alone in frontal and temporal cortical regions, as well as in subcortical areas linked with emotion and motivational regulation. Although the limited prescan exposure to marijuana in these adolescents tentatively suggests that these findings may reflect underlying differences, the direct effect of cannabis exposure may also be involved.

Altered cortical maturation in adolescent cannabis users with and without schizophrenia

“…Similarly, a comparison of bipolar adolescents reported increased GM volume in right caudate and right precentral gyrus in CUD (+) compared to CUD (−) (Jarvis et al, 2008). These data suggest a similar effect of cannabis on adolescent brain morphology (regardless of diagnosis) and substantiate the findings observed in this study.…”

“…The CUD + EOS group was particularly small (n = 11). However, we were able to detect a significant main effect of CUD across diagnostic groups, and this finding is supported by previous cross-sectional studies in other adolescent cannabis users (Cousijn et al, 2012;Medina et al, 2009;Medina et al, 2010), including adolescent cannabis users with bipolar disorder (Jarvis et al, 2008). Second, this was a naturalistic study and we were not able to obtain "clean" groups of subjects with CUD and no other comorbid psychopathology.…”

“…e l s e v i e r . c o m / l o c a t e / s c h r e s (Cousijn et al, 2012;Squeglia et al, 2009) and atypical development (Jarvis et al, 2008). Specifically, a study of adolescent cannabis users (mean age = 17.8) found reduced cortical thickness in prefrontal and insular regions, and increased cortical thickness in temporal and parietal regions, compared to healthy controls (HC) (Lopez-Larson et al, 2011).…”

“…The present study aimed to examine the impact of CUD on cortical development in HASC over an 18-month period in both nonpsychotic and psychotic adolescents. On the basis of our cross-sectional data (Kumra et al, 2012) and the existing literature, we hypothesized that: (1) The magnitude of cortical thinning would be altered for CUD (+) compared to CUD (−) across HASC regions, based on preclinical data suggesting that adolescent exposure to cannabis could disrupt cortical GM development (Bossong and Niesink, 2010), and prior morphometric data demonstrating differences in cortical thickness and brain volumes associated with CUD in both typical (Lopez-Larson et al, 2011) and atypical development (Jarvis et al, 2008;Kumra et al, 2012); and (2) The magnitude of these alterations would be related to the amount of cannabis consumed. As an exploratory aim, we examined the relationship between neurocognitive performance and change in cortical thickness within the HASC.…”

Long-Term Effects of Cannabis on Brain Structure

“…Alterations of this phenomenon have been observed in various psychiatric conditions (Mackie et al , 2007) (Jarvis et al , 2008) (Castellanos et al , 2002) (Pujol et al , 2004) (Hill et al , 2003) and in adolescents with familiar history of severe alcohol abuse (Hill et al , 2007). …”