Differential impact of heavy cannabis use on sensory gating in schizophrenic patients and otherwise healthy controls

Chronic effects of cannabis on sensory gating

“…Chronic effects of cannabis on sensory gating 5 2009; Patrick et al, 1999;Patrick and Struve, 2002;Patrick and Struve, 2000;Rentzsch et al, 2007), and interestingly in comparison to patients with schizophrenia with and without concurrent cannabis use (Rentzsch et al, 2007). Some of these studies found that poor sensory gating in cannabis users is associated with prolonged durations of exposure (Rentzsch et al, 2007) and dose (the number of joints smoked in the previous six months, Edwards et al, 2009).…”

“…Regular and prolonged exposure to cannabis is associated with impaired cognition, particularly deficits in attention, learning and memory (Solowij and Michie, 2007;Solowij and Pesa, 2010), alterations in brain structure and function (Solowij et al, 2011;Yücel et al, 2008a;Yücel et al, 2008b), and deficits in electrophysiological indices of pre-attentive processes (e.g. P50: Edwards et al, 2009;Patrick et al, 1999;Patrick and Struve, 2002;Patrick and Struve, 2000;Rentzsch et al, 2007; and mismatch negativity, MMN: Greenwood et al, in revision; Rentzsch et al, 2011;Roser et al, 2010) as well as selective attention (e.g. processing negativity and P300: Solowij et al, 1995).…”

“…Some of these studies found that poor sensory gating in cannabis users is associated with prolonged durations of exposure (Rentzsch et al, 2007) and dose (the number of joints smoked in the previous six months, Edwards et al, 2009). The association between P50 sensory gating and propensity to develop psychotic-like symptoms associated with prolonged exposure to cannabis has not been addressed in prior work.…”

“…Further, consistent with prior work demonstrating impairments in verbal learning in cannabis users and patients with schizophrenia (Solowij and Michie, 2007), we explored a potential association between a measure of verbal learning and P50 sensory gating. Finally, prior research in cannabis users focused predominately on a ratio measure of sensory gating (Edwards et al, 2009;Patrick et al, 1999;Patrick and Struve, 2002;Patrick and Struve, 2000;Rentzsch et al, 2007), while more recent research also investigated the difference metric (P50 amplitude to S1 -P50 amplitude to S2) with mixed results (Edwards et al, 2009;Rentzsch et al, 2007). In accordance with this recent work and research which suggests that the P50 difference score may be a more reliable index of sensory gating (Smith et al, 1994), the current study compared cannabis users with controls on both P50 ratio and difference measures (see also Chang et al,…”

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

“…Sensory gating is the brain's ability to modulate its sensitivity to irrelevant sensory stimuli and thus filter out repetitive and redundant sensory stimulation [46]. Cross-sectional studies report both disrupted and intact P50 in cannabis-using schizophrenia patients [56,57]. Despite the lack of gating differences in these patient studies, it is interesting to note that P50 gating deficits in heavy chronic cannabis users have been linked to abnormal oscillatory activity [58,59], which is similarly disrupted in schizophrenia patients [45].…”