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. Author manuscript; available in PMC: 2022 Aug 30.
Published in final edited form as: Am J Psychiatry. 2022 Mar 8;179(5):362–374. doi: 10.1176/appi.ajp.2021.21060664

Table 2. Panel B.

IQ Change: Dose-response associations. Dose-response associations between persistence of cannabis use from age 18–45 and IQ change from childhood to adulthood.

Panel B1. Exposure: Persistence of Cannabis Dependence Statistical Tests
Exposure Means for IQ Change from Childhood to Adulthood as a Function of Persistence of Cannabis Dependencea Model 1: Adjusted for sex Model 2: +Adjustment for other substance useb Model 3: + Adjustment for childhood SES, low childhood self-control, and family history of substance-dependencec
Persistence of Cannabis Dependence Never used (n=255) Used but never diagnosed (N=496) 1 diagnosis (N=83) 2 diagnoses (N=39) 3 diagnoses (N=32) 4+ diagnoses (N=15) β 95% CI p β 95% CI p β 95% CI p
0.21 −0.02 −0.18 −0.17 −0.40 −0.66 −0.16 −0.23, −0.10 <.001 −0.09 −0.18, −0.01 .02 −0.10 −0.18, −0.01 .02
Panel B2. Exposure: Persistence of Regular Cannabis Use Statistical Tests
Exposure Means for IQ Change from Childhood to Adulthood as a Function of Persistence of Regular Cannabis Usea Model 1: Adjusted for sex Model 2: +Adjustment for other substance useb Model 3: + Adjustment for childhood SES, low childhood self-control, and family history of substance-dependencec
Persistence of Regular Cannabis Use Never used (n=255) Used but never regularly (n=516) Regularly used 1x (n=55) Regularly used 2x (n=32) Regularly used 3x (n=33) Regularly used 4+x (n=29) β 95% CI p β 95% CI p β 95% CI p
0.21 −0.01 −0.26 −0.29 −0.27 −0.52 −0.16 −0.23, −0.10 <.001 −0.10 −0.18, −0.02 .01 −0.10 −0.18, −0.03 .01

Note.

a.

Means represent unadjusted IQ change scores (adult IQ minus child IQ) that were standardized on the full sample prior to analysis (M=0, SD=1).

b.

Statistical tests were adjusted for sex and persistent use of tobacco, alcohol, and other illicit drugs.

c.

Statistical tests were adjusted for sex; persistent use of tobacco, alcohol, and other illicit drugs; low childhood SES; low childhood self-control; and family history of substance dependence. Beta coefficients represent standardized estimates. Bolded estimates are statistically significant (p<.05).