Table 2.
Neuropsychological Performance of Current, Former and Never-Smokers as a Function of Psychiatric Diagnosis.
| Neuropsychological Outcome Measure |
SZ Current Smokers (n=38) |
SZ Former Smokers (n=17) |
SZ Never- Smokers (n=12) |
Smoking History Effect (1-way ANOVA) |
CON Current Smokers (n=31) |
CON Former Smokers (n=16) |
CON Never- Smokers (n=26) |
Smoking History Effect (1-way ANOVA) |
Diagnosis Effect (2-way ANOVA) |
Smoking History Effect (2-way ANOVA) |
Diagnosis × Smoking History Interaction |
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|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
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| F (df) | p | F (df) | p | F (df) | p | F (df) | p | F (df) | P | |||||||
|
| ||||||||||||||||
| CPT Hit Rate (%) | 98.0± 2.6 | a 99.0+1.0 | 96.1± 4.6 | 3.8 (2,64) | 0.03 | 99.1±1.0 | 98.6±2.1 | 99.4±0.8 | 2.1 (2,70) | 0.13 | 12.0 (1,134) | .001 | 2.2 (2,134) | 0.12 | 6.3 (2,134) | <0.01 |
|
CPT Commission Rate
(%) |
28.6±14.6 | 25.8±18.1 | 39.1± 27.2 | 2.0 (2,64) | 0.14 | 26.2±18.7 | 26.4±15.7 | 19.8±13.1 | 1.3 (2,70) | 0.27 | 4.9 (1,132) | 0.03 | 0.3 (2,132) | 0.73 | 3.4 (2,132) | 0.04 |
|
CPT Hit Rate Reaction
Time (ms) |
422.4±92.3 | 441.8± 90.2 | 441.8±74.2 | 0.4 (2,64) | 0.68 | 373.2±82.5 | 424.7±84.8 | 371.4±84.4 | 2.5(2,70) | 0.09 | 8.4 (1,134) | <0.01 | 1.9 (2,134) | 0.15 | 0.8 (2,134) | 0.45 |
| CPT Variability Index | 13.7±10.6 | 10.6±5.2 | 19.2±17.6 | 2.1 (2,64) | 0.13 | 8.3±5.9 | 8.5±4.6 | 6.6±5.7 | 0.8 (2,70) | 0.45 | 17.8 (1,134) | <0.01 | 1.3 (2,134) | 0.29 | 3.2 (2,134) | 0.05 |
| CPT Attentional Index | 2.1±1.1 | 2.8±1.1 | 1.9±1.5 | 2.4 (2,64) | 0.10 | 3.0±1.3 | 1.9±1.6 | 2.6±1.4 | 2.8 (2,70) | 0.07 | 1.1 (1,134) | 0.29 | 0.6 (2,134) | 0.57 | 4.9 (2,134) | <0.01 |
| SCWT Incongruent (ms) | a1179±468 | a1040±106 | 1855±1050 | 4.7 (2,37) | 0.02 | 1054±450 | 1006±300 | 1027±603 | 0.02 (2,43) | 0.97 | 5.4 (1,80) | 0.02 | 3.3 (2,80) | 0.04 | 5.4 (2,80) | 0.04 |
| SCWT Congruent (ms) | a 894±249 | a 859± 78 | 1392±512 | 9.0 (2,37) | <0.01 | 780±203 | 739±155 | 750±396 | 0.09 (2,43) | 0.92 | 14.8 (1,80) | <0.01 | 5.4 (2,80) | <0.01 | 6.5 (2,80) | <0.01 |
| SCWT Neutral (ms) | a 914±190 | a 865±133 | 1314±422 | 8.9 (2,36) | <0.01 | 744±234 | 765±147 | 843±530 | 0.3 (2,44) | 0.68 | 9.2 (1,80) | <0.01 | 5.1 (2,80) | 0.01 | 2.0 (2,80) | 0.14 |
| SCWT Interference (ms) | 286±374 | 130±114 | 448±869 | 0.8 (2,37) | 0.46 | 306±347 | 162±128 | 236±423 | 0.4 (2,41) | 0.75 | 0.2 (1,80) | 0.64 | 0.8 (2,80) | 0.46 | 0.6 (2,80) | 0.57 |
| SCWT Facilitation | 7.6±185 | 6.6±124 | 22.0±294 | 0.01(2,36) | 0.98 | 39.6±249 | 128±222 | 55.6±207 | 0.02 (2,41) | 0.69 | 1.1 (1,80) | 0.29 | 0.2 (2,80) | 0.83 | 0.2 (2,80) | 0.82 |
| WCST Errors (%) | 24.9±15.5 | 30.2±17.5 | 30.3±18.2 | 0.8 (2,60) | 0.46 | 20.5±17.1 | 25.0±20.7 | 17.3±10.0 | 1.1 (2,69) | 0.33 | 6.1 (1,129) | 0.02 | 0.9 (2,129) | 0.40 | 0.8 (2,129) | 0.45 |
|
WCST Perseverative
Errors (%) |
14.4±11.2 | 16.1±10.1 | 18.8±17.3 | 0.6 (2,60) | 0.55 | 11.4±11.0 | 15.2±16.0 | 9.2±5.4 | 1.6 (2,69) | 0.24 | 4.2 (1,129) | 0.04 | 0.6 (2,129) | 0.57 | 0.3 (2,129) | 0.28 |
|
WCST Perseverative
Responses |
13.9±9.9 | 18.1±12.3 | 22.6±23.6 | 1.8 (2,60) | 0.17 | 12.3±14.5 | 17.6±20.3 | 9.5±5.9 | 1.5 (2,67) | 0.21 | 3.6 (1,125) | 0.06 | 1.3 (2,125) | 0.28 | 2.1 (2,125) | 0.12 |
|
WCST Nonperseverative
Responses (%) |
10.5±6.7 | 14.3±8.8 | 11.3±5.7 | 1.4 (2,60) | 0.25 | 9.0±8.2 | 9.9±6.5 | 8.0±5.5 | 0.4 (2,69) | 0.69 | 5.4 (1,129) | 0.02 | 1.3 (2,129) | 0.27 | 0.5 (1,129) | 0.63 |
|
WCST Categories
Completed |
4.7±2.2 | 4.0± 2.7 | 4.3±2.2 | 0.5 (2,60) | 0.60 | 5.2±1.7 | 4.9±2.1 | 5.8±1.0 | 1.9 (2,69) | 0.16 | 6.4 (1,129) | 0.01 | 0.9 (2,129) | 0.40 | 0.8 (2,129) | 0.47 |
Abbreviations: CPT, Continuous Performance Test; SCWT, Stroop Color Word Test; WCST, Wisconsin Card Sorting Task; SZ, Schizophrenia; CON, Control.
a
represents a significant difference in performance compared to the SZ never-smoker subgroup (Bonferroni post hoc tests corrected for multiple comparisons, p≤0.04)