TY - JOUR
T1 - Cannabis and cognitive performance in psychosis: a cross-sectional study in patients with non-affective psychotic illness and their unaffected siblings
AU - Meijer, J.H.
AU - Dekker, N.
AU - Koeter, M.W.J.
AU - Quee, P.J.
AU - Beveren, N.J.
AU - Meijer, C.J.
AU - Kahn, R. S.
AU - Linszen, D.H.
AU - van Os, J.
AU - Wiersma, D.
AU - Bruggeman, R.
AU - Cahn, W.
AU - de Haan, L.
AU - Krabbendam, L.
AU - Myin-Germeys, I.
PY - 2012
Y1 - 2012
N2 - Background The relationship between cannabis use and cognitive functioning in patients with psychosis has yielded contradictory findings. In individuals at genetic high risk for psychosis, information is sparse. The aim of this study was to assess the association between recency and frequency of cannabis use and cognitive functioning in patients with psychosis and their unaffected siblings.Method We conducted a cross-sectional study in 956 patients with non-affective psychosis, 953 unaffected siblings, and 554 control subjects. Participants completed a cognitive test battery including assessments of verbal learning, set shifting, sustained attention, processing speed, working memory, acquired knowledge, reasoning and problem solving and social cognition. Cannabis use was assessed by urinalysis and by the Composite International Diagnostic Interview. Using random-effect regression models the main effects of cannabis (recency and frequency) and the interaction with status (patient, sibling, control) on cognitive functioning were assessed. Results Current cannabis use was associated with poorer performance on immediate verbal learning, processing speed and working memory (Cohen's d+0.20 to+0.33, p<0.005). Lifetime cannabis use was associated with better performance on acquired knowledge, facial affect recognition and face identity recognition (Cohen's d+0.17 to +0.33, p<0.005). There was no significant interaction between cannabis and status on cognitive functioning. Conclusions Lifetime cannabis-using individuals might constitute a subgroup with a higher cognitive potential. The residual effects of cannabis may impair short-term memory and processing speed. © 2011 Cambridge University Press.
AB - Background The relationship between cannabis use and cognitive functioning in patients with psychosis has yielded contradictory findings. In individuals at genetic high risk for psychosis, information is sparse. The aim of this study was to assess the association between recency and frequency of cannabis use and cognitive functioning in patients with psychosis and their unaffected siblings.Method We conducted a cross-sectional study in 956 patients with non-affective psychosis, 953 unaffected siblings, and 554 control subjects. Participants completed a cognitive test battery including assessments of verbal learning, set shifting, sustained attention, processing speed, working memory, acquired knowledge, reasoning and problem solving and social cognition. Cannabis use was assessed by urinalysis and by the Composite International Diagnostic Interview. Using random-effect regression models the main effects of cannabis (recency and frequency) and the interaction with status (patient, sibling, control) on cognitive functioning were assessed. Results Current cannabis use was associated with poorer performance on immediate verbal learning, processing speed and working memory (Cohen's d+0.20 to+0.33, p<0.005). Lifetime cannabis use was associated with better performance on acquired knowledge, facial affect recognition and face identity recognition (Cohen's d+0.17 to +0.33, p<0.005). There was no significant interaction between cannabis and status on cognitive functioning. Conclusions Lifetime cannabis-using individuals might constitute a subgroup with a higher cognitive potential. The residual effects of cannabis may impair short-term memory and processing speed. © 2011 Cambridge University Press.
U2 - 10.1017/S0033291711001656
DO - 10.1017/S0033291711001656
M3 - Article
SN - 0033-2917
VL - 42
SP - 705
EP - 716
JO - Psychological Medicine
JF - Psychological Medicine
IS - 4
ER -
