TABLE 1.
Demographic Features and Clinical Characteristics for Participants
| HC (n=53) |
CUD (n=29) |
EOS (n=34) |
EOS+CUD (n=18) |
χ2 or F | |
|---|---|---|---|---|---|
| Demographic Features | |||||
| Sex, male | 26 | 20 | 15 | 14 | 8.43* |
| Mean age, years (SD) | 16.4 (2.6) | 17.4 (2.3) | 16.5 (1.9) | 17.7 (1.2) | 2.63 |
| Handedness, right | 45 | 28 | 28 | 16 | 3.31 |
| Clinical Characteristics, Means | |||||
| Psychosis age of onset, years (SD) | - | - | 12.5 (3.4) | 14.9 (2.6) | 6.50* |
| BPRSc total score (SD) | - | - | 22.7 (12) | 21.9 (16) | .04 |
| SANSd total score (SD) | - | - | 9.3 (4.9) | 7.2 (5.0) | 1.94 |
| Cannon-Spoor premorbid adjustment | - | - | 9.5 (3.8) | 7.9 (3.5) | 2.09 |
| Currente CPZf antipsychotic dose, 100 CPZ equivalents (SD) | - | 1.4 (.78) | 2.7 (1.8) | 2.8 (2.0) | 1.15 |
| Lifetimeg CPZf exposure, dose-years (SD) | 0 (0) | .06 (.21) | 2.24 (2.7)a,b | 2.74 (2.9)a,b | 21.00*** |
| Age of onset, cannabis use (SD) | - | 12.7 (2.5) | - | 12.9 (1.9) | .074 |
| Lifetime cannabis episodes (SD) | - | 934 (483) | - | 953 (456) | .02 |
| Median days since last use (SD) | - | 57 | - | 80 | |
| Urine analysis for cannabis, positive | 0 | 11 | 0 | 7 | 38.50*** |
| Cigarette smoking, yes | 1 | 14 | 1 | 6 | 37.86*** |
| Alcohol Drinking, yes | 8 | 19 | 3 | 8 | 32.98*** |
| Cognitive measures | |||||
| WRATh Reading decoding scores (SD) | 111 (16) | 104 (17) | 103 (19)a | 95 (13)a | 4.73** |
| WASIi full-scale IQ | 116 (9) | 100 (14)a | 90 (17)a,b | 90 (16)a,b | 29.33*** |
| ANTj mean reaction time, ms (SD) | 603 (70) | 636 (108) | 702 (86)a,b | 652 (128) | 8.05*** |
| ANTj mean accuracy, % (SD) | 96 (3.4) | 94 (8.8) | 88 (13.3)a,b | 93 (7.7) | 6.17** |
Note: HC=healthy controls; CUD=cannabis use disorder; EOS=early-onset schizophrenia; EOS+CUD=EOS with comorbid CUD;
a
Significant difference from HC, p<.05;
b
Significant difference from CUD;
c
BPRS=Brief Psychiatric Rating Scale;
d
SANS=Scale for Assessment of Negative Symptoms;
e
Current dose based on participants taking antipsychotic medications at time of scan (5 CUD, 27 EOS, 18 EOS+CUD);
f
CPZ=chlorpromazine equivalents;
g
Estimates of lifetime CPZ exposure includes all members of patient groups;
h
WRAT=Wide Range Achievement Test;
i
WASI=Weschler Abbreviated Scale of Intelligence;
j
ANT=Attention Network Test.
*
p<.05
**
p<.01
***
p<.001