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. Author manuscript; available in PMC: 2018 Sep 1.
Published in final edited form as: Am J Psychiatry. 2017 Dec 5;175(3):275–283. doi: 10.1176/appi.ajp.2017.16111203

Table 1.

Demographic, clinical, and performance characteristics of sample.

Schizophrenia
Patients
(n = 52)		 Healthy
Comparison
Participants
(n = 41)
n % n % Statistic p
Demographics
    Gender (Female/Male) 15/37 28.8/71.2 6/35 14.6/85.4 χ2(1) = 2.65 0.136
    Cigarette Smoker (Yes/No) 16/36 30.8/69.2 5/36 12.2/87.8 χ2(1) = 4.52 0.033
M SD M SD Statistic p
    Age (years) 26.10 8/17 30.22 7.07 F(1,91) = 6.56 0.012
    Education (years) 13.10 2.19 14.44 1.98 F(1,91) = 9.40 0.003
    Parental Education (years) 14.02 3.54 15.07 2.65 F(1,91) = 2.52 0.116
    CPZ-Equiv. Dose(mg/day) 204.17 116.26
    Age of Psychosis Onset (years) 22.59 3.89
    Cigarettes in Past Week (no.) 4.60 15.36 1.71 5.08 F(1,91) = 1.33 0.251
Symptoms (summary scores)
    SAPS 4.17 3.55
    SANS 8.98 4.34
Cognition (T-scores)a
    Working Memory 43.26 15.45
    Speed of Processing 32.26 12.00
    Attention/Vigilanceb 37.39 12.29
    Verbal Learning 42.41 10.16
    Visual Learning 38.59 11.27
    Reasoning/Problem Solving 38.67 9.03
    Social Cognitionb 41.34 12.49
    MCCB Overall Compositec 32.81 14.42
P50 Measures
    S1 Amplitude (µV) 2.88 1.65 3.50 1.84 F(1,91) = 2.93 0.090
    S2 Amplitude (µV) 1.56 1.11 1.44 1.21 F(1,91) = 0.26 0.612
    S2/S1 Ratio Score 0.60 0.41 0.39 0.28 F(1,91) = 7.87 0.006

Note. Numbers and percentages of participants are reported for gender and cigarette smoking status, which was analyzed using a Pearson chi-square test. Group means (M) and standard deviations (SD) are reported for age, personal and parental years of education, and number of cigarettes consumed in the past week, which were analyzed using analysis of variance (ANOVA). Group mean (M) and standard deviation (SD) of the schizophrenia patient sample are reported for chlorpromazine (CPZ)-equivalent dosages, age of psychosis onset, total scores on the Scale for the Assessment of Positive Symptoms (SAPS) and on the Scale for the Assessment of Negative Symptoms (SANS), and norm-based T-scores on the MATRICS Consensus Cognitive Battery (MCCB). Mean P50 Stimulus 1 (S1) and Stimulus 2 (S2) amplitudes and S2/S1 Ratios are reported for both groups.

a

Data were collected from a subset of 39 schizophrenia participants who completed cognitive evaluation.

b

Data unavailable for 1 participant.

c

Data unavailable for 2 participants.