Substance use and withdrawal: Neuropsychological functioning over 8 years in youth

Abstract

This study prospectively examined neuropsychological (NP) functioning associated with adolescent substance use and withdrawal. Participants were youths with histories of substance use disorders (n = 47) and demographically comparable youths with no such lifetime histories (n = 26). They were followed with NP testing and substance involvement interviews at 7 time points spanning 8 years, from ages 16 to 24, on average. After controlling for recent use, age, education, practice effects, and baseline NP functioning, substance use over the 8-year follow-up period significantly predicted performances on tests of memory and attention at Year 8. Additionally, withdrawal symptoms during the follow-up predicted visuospatial and attention scores at Year 8. Findings suggest that use and withdrawal may differentially impact neurocognitive functioning during youth, with heavy use leading to learning, retention, and attentional difficulties, and withdrawal leading to problems with visuospatial functioning. (JINS, 2002, 8, 873–883.)

Abstinent adolescent marijuana users show altered fMRI response during spatial working memory

“…Such occipital hyperactivation among MJ teens was not observed during SWM blocks, during which attentional resources were not focused solely on visual selective attention, but allocated to accommodate working memory processing. Previous studies have implicated diminished attentional capacity in heavy marijuana-using adults (Solowij et al, 1991(Solowij et al, , 1995Chang et al, 2006) and adolescents (Tapert et al, 2002;Schweinsburg et al, 2005b). During SWM, MJ teens may allocate limited attentional resources to spatial processing, depriving attentional input to executive systems, resulting in increased parietal and decreased frontal activation.…”

“…Among polysubstance using youths, marijuana use has been linked to poorer learning and memory (Millsaps et al, 1994) and attention (Tapert et al, 2002). In a longitudinal study, Fried and colleagues (Fried et al, 2005) assessed cognitive functioning in 9-to 12-year-olds before the initiation of marijuana use, and again when youths were ages 17-21.…”

fMRI response to spatial working memory in adolescents with comorbid marijuana and alcohol use disorders

“…Thus, it appears that teens with marijuana and alcohol use disorders have aberrant patterns of functional response not observed in teens with AUD alone, especially in frontal systems. Heavy marijuana use during adolescence may adversely affect frontal functioning more than other brain regions (Kanayama et al, 2004;Loeber and Yurgelun-Todd, 1999;Lundqvist et al, 2001), and may be related to problems with attention (Solowij et al, 1991(Solowij et al, , 1995Tapert et al, 2002) as well as working memory (Schwartz et al, 1989). Further, protracted recent marijuana and alcohol use during adolescence appears associated with disrupted attention and working memory networks above and beyond the abnormalities observed in teens with AUD alone.…”

“…Neuropsychological studies of teens with alcohol use disorders (AUD) have reported decrements in language skills, problem solving, verbal and non-verbal retention, working memory, and visuospatial performance (Brown et al, 2000;Moss et al, 1994;Tapert et al, 2002). In addition, we previously examined functional magnetic resonance imaging (fMRI) brain response during a spatial working memory (SWM) task among teens with AUD and demographically similar non-abusing controls (Tapert et al, 2004).…”

“…Neuropsychological assessments of substance use disordered teens have described marijuana use related deficits in learning and memory (Millsaps et al, 1994) and attention (Tapert et al, 2002). A longitudinal study of marijuana dependent adolescents demonstrated further shortterm memory decrements that persisted after 6 weeks of monitored abstinence (Schwartz et al, 1989).…”