Alterations to pre-pulse inhibition (PPI) in chronic cannabis users are secondary to sustained attention deficits

Abstract

Cannabis users showed an attention-dependant alteration in PPI, which appeared to reflect a deficit in sustain attention, and which was different to that which has been observed in schizophrenia using the same methodology.

Neurobiology of Comorbid Substance Use Disorders in Mental Illness: A Closer Look at the Underlying Commonalities between Cannabis and Schizophrenia

“…Kedzior and Martin-Iverson [47] impaired attentional modulation and reduced PPI among chronic users relative to controls. Other studies are consistent with these results [48,49], but not all [50]. In examining the interaction between schizophrenia and cannabis use on PPI, impaired modulation of PPI was demonstrated in schizophrenia patients (users and non-users) and in control users compared with non-cannabis-using controls [51].…”

Dexamphetamine selectively increases 40 Hz auditory steady state response power to target and nontarget stimuli in healthy humans

“…A similar design (playing a visual electronic game v. listening to repetitive clicks) found effects attributed to attention that were later confirmed to be largely attentional in a more balanced attention condition. 55 As there are strong effects of attention on the ASSR, it seems more likely that attention differences accounted for the differences in arousal state in their study. Further, a primary effect of dexamphetamine is to increase arousal, yet dexamphetamine administration increased the 40 Hz ASSR.…”

Corticosteroid dependent and independent effects of a cannabinoid agonist on core temperature, motor activity, and prepulse inhibition of the acoustic startle reflex in Wistar rats

“…Cannabinoid receptor knock-out mice have been proposed as an animal model of schizophrenia (Black et al 2011;Fritzsche 2001). On the other hand, chronic use of cannabinoids is associated with schizophrenic-like attentiondependent deficits in PPI (Kedzior and Martin-Iverson 2006;Scholes and Martin-Iverson 2009), and acute use of cannabis is associated with other cognitive dysfunctions similar to those observed in schizophrenia (Long et al 2006;Solowij and Michie 2007). All of these and similar disparate findings appear to parallel the current observations that the corticosteroid-independent cannabinoid effects increased PPI of the response capacity measure while reduced PPI of the stimulus measures.…”