Table 1.
Sociodemographic, Clinical, and Cognitive Characteristics of the Study Sample
| SZ (n = 71) | SAD (n = 70) | BDP (n = 86) | SZ-Rel (n = 74) | SAD-Rel (n = 62) | BDP-Rel (n = 88) | HC (n = 145) | Test Statistic | P Value | |
|---|---|---|---|---|---|---|---|---|---|
| Sociodemographic characteristics | |||||||||
| Age, years; Mean (SD) | 35.9 (12.4) | 37.6 (12.7) | 35.8 (13.2) | 40.7 (16.1) | 39.3 (15.4) | 38.9 (16.2) | 38.4 (12.4) | F(6,589) = 1.24 | .29 |
| Sex/Male; n (%) | 44 (62.0) | 32 (45.7) | 25 (29.1) | 18 (24.3) | 18 (29.0) | 28 (31.8) | 67 (46.2) | χ2(6) = 34.49 | <.001a |
| Handedness; n (%)b | χ2(12) = 20.11 | .07 | |||||||
| Right handed | 59 (83.1) | 64 (91.4) | 72 (83.7) | 66 (89.2) | 59 (95.2) | 74 (84.1) | 129 (89.0) | ||
| Left handed | 9 (12.7) | 3 (4.3) | 14 (16.3) | 6 (8.1) | 2 (3.2) | 14 (15.9) | 13 (9.0) | ||
| Ambidextrous | 1 (1.4) | 3 (4.3) | 0 (0.0) | 0 (0.0) | 0 (0.0) | 0 (0.0) | 1 (0.7) | ||
| Ethnicity/Hispanic; n (%) | 10 (14.2) | 6 (8.6) | 6 (7.0) | 11 (14.9) | 3 (4.8) | 8 (9.1) | 22 (15.2) | χ2(6) = 8.22 | .22 |
| Race; n (%) | χ2(12) = 51.24 | <.001c | |||||||
| Caucasian | 32 (45.1) | 32 (45.7) | 61 (70.9) | 39 (52.7) | 41 (66.1) | 75 (85.2) | 96 (66.2) | ||
| African American | 34 (47.9) | 35 (50.0) | 19 (22.1) | 28 (37.8) | 19 (30.6) | 11 (12.5) | 36 (24.8) | ||
| Other | 5 (7.0) | 3 (4.3) | 6 (7.0) | 7 (9.5) | 2 (3.2) | 2 (2.3) | 13 (9.0) | ||
| Education, years; Mean (SD) | 12.8 (2.5) | 13.3 (2.5) | 14.2 (2.5) | 14.0 (2.3) | 13.8 (2.9) | 14.6 (2.8) | 14.5 (2.3) | F(6,581) = 5.59 | <.001d |
| Clinical characteristics; Mean (SD) | |||||||||
| Age of illness onset, years | 20.4 (8.3) | 19.0 (9.4) | 19.8 (9.2) | — | — | — | — | F(2,222) = 0.46 | .63 |
| Age of first hospitalization, years | 22.6 (7.5) | 24.2 (9.4) | 24.7 (10.1) | — | — | — | — | F(2,190) = 0.92 | .4 |
| Number of lifetime hospitalizations | 5.6 (6.5) | 6.6 (7.0) | 4.6 (6.0) | — | — | — | — | F(2,185) = 1.34 | .26 |
| PANSS | |||||||||
| Total | 75.9 (15.7) | 74.6 (14.0) | 58.8 (13.6) | — | — | — | — | F(2,220) = 34.33 | <.001e |
| Positive subscale | 19.4 (4.9) | 20.3 (4.1) | 13.8 (4.2) | — | — | — | — | F(2,220) = 50.66 | <.001 |
| Negative subscale | 19.2 (6.3) | 16.1 (4.6) | 13.4 (4.3) | — | — | — | — | F(2,220) = 24.39 | <.001 |
| General symptoms subscale | 37.3 (7.8) | 38.2 (7.8) | 31.6 (7.9) | — | — | — | — | F(2,220) = 16.24 | <.001 |
| YMRS | 7.2 (5.8) | 8.4 (5.5) | 5.8 (6.2) | — | — | — | — | F(2,220) = 4.81 | .009f |
| MADRS | 10.1 (8.1) | 14.5 (9.6) | 10.9 (9.3) | — | — | — | — | F(2,220) = 3.79 | .02g |
| GAF | 43.1 (9.7) | 44.5 (9.7) | 58.9 (12.0) | 76.0 (12.3) | 76.1 (12.9) | 75.2 (12.1) | 86.2 (5.0) | F(6, 586) = 234.32 | <.001h |
| Cognitive characteristics | |||||||||
| WRAT IQ, Mean (SD) | 92.5 (16.5) | 96.2 (13.7) | 102.2 (14.2) | 94.9 (15.0) | 101.3 (17.0) | 102.5 (13.3) | 100.9 (14.2) | F(6,580) = 5.76 | <.001i |
| BACS, z-score, Mean (SD) | |||||||||
| Composite | −1.7 (1.2) | −1.4 (.2) | −0.9 (1.3) | −0.5 (1.1) | −0.3 (1.3) | −0.08 (1.2) | −0.09 (1.2) | F(6,570) = 21.8 | <.001j |
| Verbal memory | −1.1 (1.3) | −0.8 (1.3) | −0.5 (1.3) | −0.4 (1.3) | −0.2 (1.1) | −0.2 (1.2) | −0.1 (1.1) | F(2,533) = 5.82 | <.001 |
| Digit sequencing | −1.2 (1.2) | −0.9 (1.2) | −0.7 (1.2) | −0.4 (1.1) | −0.2 (1.1) | −0.04 (1.1) | −0.2 (1.2) | F(2,533) = 9.9 | <.001 |
| Token motor | −1.3 (1.2) | −1.5 (1.0) | −0.9 (1.3) | −0.4 (1.0) | −0.2 (0.9) | −0.2 (1.0) | −0.02 (1.1) | F(2,527) = 20.9 | <.001 |
| Verbal fluency | −0.8 (1.2) | −0.3 (1.1) | −0.2 (1.1) | −0.1 (1.1) | 0.2 (1.3) | 0.2 (1.2) | 0.1 (1.1) | F(2, 33) = 6.34 | <.001 |
| Symbol coding | −1.3 (1.1) | −1.2 (1.2) | −0.9 (1.0) | −0.5 (1.1) | −0.2 (1.0) | −0.2 (1.0) | 0.02 (1.0) | F(2,533) = 19.6 | <.001 |
| Tower of London | −0.8 (1.4) | −0.6 (1.3) | −0.2 (1.2) | −0.2 (1.0) | −0.2 (1.2) | 0.2 (0.8) | −0.002 (1.1) | F(2,532) = 6.6 | <.001 |
| Concomitant medications; n (%)b | |||||||||
| Off-psychotropic medications | 7 (9.9) | 6 (8.6) | 5 (5.9) | 61 (82.4) | 43 (69.4) | 57 (64.8) | 140 (96.6) | — | — |
| Antipsychotics (any) | 62 (87.3) | 59 (84.3) | 65 (75.6) | 1 (1.4) | 2 (3.2) | 5 (5.7) | 0 (0.0) | — | — |
| Typical | 9 (12.7) | 5 (7.1) | 8 (9.3) | 0 (0.0) | 0 (0.0) | 0 (0.0) | 0 (0.0) | — | — |
| Atypical | 53 (74.7) | 54 (77.1) | 57 (66.3) | 1 (1.4) | 2 (3.2) | 5 (5.7) | 0 (0.0) | — | — |
| Mood stabilizers (any) | 14 (19.7) | 38 (54.3) | 57 (66.3) | 0 (0.0) | 6 (9.7) | 8 (9.1) | 0 (0.0) | — | — |
| Lithium | 3 (4.2) | 7 (10.0) | 20 (23.3) | 0 (0.0) | 2 (3.2) | 2 (2.3) | 0 (0.0) | — | — |
| Other | 11 (15.5) | 31 (44.3) | 37 (43.0) | 0 (0.0) | 4 (6.5) | 6 (6.8) | 0 (0.0) | — | — |
| Antidepressants (any) | 26 (36.6) | 36 (51.4) | 42 (48.8) | 10 (13.5) | 15 (24.2) | 19 (21.6) | 1 (0.7) | — | — |
| Tricyclic | 1 (1.4) | 0 (0.0) | 2 (2.3) | 1 (1.4) | 1 (1.6) | 0 (0.0) | 0 (0.0) | — | — |
| Other (SSRI, SNRI, etc.) | 25 (35.2) | 36 (51.4) | 40 (46.5) | 9 (12.2) | 14 (22.6) | 19 (21.6) | 1 (0.7) | — | — |
| Antiparkinsonian | 11 (15.5) | 7 (10.0) | 8 (9.3) | 0 (0.0) | 0 (0.0) | 0 (0.0) | 0 (0.0) | — | — |
| Stimulants | 6 (8.5) | 4 (5.7) | 7 (8.1) | 0 (0.0) | 3 (4.8) | 6 (6.8) | 0 (0.0) | — | — |
| Combined medications | 43 (60.6) | 57 (81.4) | 67 (77.9) | 3 (4.1) | 7 (11.3) | 10 (11.4) | 0 (0.0) | — | — |
Note: SZ, probands with schizophrenia; SAD, probands with schizoaffective disorder; BDP, probands with psychotic bipolar I disorder; SZ-Rel, relatives of probands with schizophrenia; SAD-Rel, relatives of probands with schizoaffective disorder; BDP-Rel, relatives of probands with psychotic bipolar I disorder; HC, healthy controls; PANSS, the Positive and Negative Syndrome Scale; YMRS, the Young Mania Rating Scale; MADRS, the Montgomery-Asberg Depression Rating Scale; GAF, the Global Assessment of Functioning; WRAT, Wide Range Achievement Test IQ estimate; BACS, the Brief Assessment of Cognition in Schizophrenia.
aSex: Higher proportion of males in (1) SZ vs BDP (χ2(1) = 15.78, P < .001), all relative groups (SZ-Rel [χ2(1) = 19.47, P < .001], SAD-Rel [χ2(1) = 13.14, P < .001], BDP-Rel [χ2(1) = 13.23, P < .001]), and HC (χ2(1) = 4.13, P = .04); (2) SAD vs BDP (χ2(1) = 3.92, P < .047) and SZ-Rel (χ2(1) = 6.35, P = .01); and (3) HC vs BDP (χ2(1) = 6.35, P = .01) and all relative groups (SZ-Rel [χ2(1) = 8.98, P = .003], SAD-Rel [χ2(1) = 4.95, P = .03], BDP-Rel [χ2(1) = 4.48, P = .03]).
bMissing data: (1) Handedness: 2/71 SZ, 2/74 SZ-Rel, 1/62 SAD-Rel, 2/145 HC; (2) Concomitant medications: 2/71 SZ, 2/74 SZ-Rel, 1/62 SAD-Rel, 1/88 BDP-Rel, 1/145 HC. Each psychotropic medication class in each subject is reported separately. The number of subjects who were treated with more than 1 psychotropic medication is indicated under “Combined medications.”
cRace: Higher proportion of African Americans in (1) SZ vs BDP (χ2(1) = 10.89, P = .001), HC (χ2(1) = 10.28, P = .001), and relatives (SAD-Rel [χ2(1) = 4.3, P = .04], BDP-Rel [χ2(1) = 25.04, P < .001]; and (2) SAD vs BDP [χ2(1) = 11.54, P < .001], HC [χ2(1) = 11.01, P < .001], and relatives (SAD-Rel [χ2(1) = 4.67, P = .03], BDP-Rel [χ2(1) = 26.03, P < .001]). Lower proportion of African Americans in BDP vs SZ-Rel [χ2(1) = 4.66, P = .03].
dEducation: Lower years of education in (1) SZ vs BDP (P = .009), BDP-Rel (P < .001), and HC (P < .001); (2) SAD vs BDP-Rel (P = .02) and HC (P = .02).
ePANSS/total: Lower scores in BDP vs SZ (P < .001) and SAD (P < .001). PANSS/positive: Lower scores in BDP vs SZ (P < .001) and SAD (P < .001). PANSS/negative: Lower scores in BDP vs SZ (P < .001) and SAD (P = .002). PANSS/general: Lower scores in BDP vs SZ (P < .001) and SAD (P < .001).
fYMRS: Higher scores in SAD vs BDP (P = .02).
gMADRS: Higher scores in SAD vs BDP (P = .03).
hGAF: Lower scores in (1) all proband and relative groups vs HC (all P < .001); (2) SZ and SAD vs BDP, all relative groups, and HC (all P < .001).
iWRAT: (1) Lower scores in SZ vs BDP (P < .001), SAD-Rel (P < .01), BDP-Rel (P < .001), and HC (P < .002); (2) SZ-Rel vs BDP (P = .03) and BDP-Rel (P = .02).
jBACS composite: (1) Lower scores in SZ vs BDP (P = .002), all relative groups (P < .001), and HC (P < .001); (2) SAD vs BDP, all relatives and HC (all P < .001); (3) BDP vs SAD-Rel (P = .045), BDP-Rel and HC (all P < .001). Verbal memory: (1) Lower scores in SZ vs SZ-Rel (P = .02), SAD-Rel (P = .006), BDP-Rel and HC (all P < .001); (2) SAD vs HC (P = .01). Digit sequencing: (1) Lower scores in SZ vs BDP (P = .048), all relatives and HC (all P < .001); (2) SAD vs SAD-Rel (P = .03), BDP-Rel and HC (all P < .001); BDP vs BDP-Rel (P = .006). Token motor: (1) Lower scores in SZ vs all relatives and HC (all P < .001); (2) SAD vs BDP (P = .01), all relatives and HC (all P < .001). Verbal fluency: (1) Lower scores in SZ vs BDP (P = .04); SZ-Rel (P = .02); SAD-Rel, BDP-Rel, and HC (all P < .001). Symbol coding: (1) Lower scores in SZ and SAD vs all relatives and HC (all P < .001, except for SAD vs SZ-Rel, P = .006); (2) BDP vs SAD-Rel (P = .009), BDP-Rel and HC (P < .001). Tower of London: (1) Lower scores in SZ and SAD vs BDP-Rel and HC (all P < .001, except for SAD vs HC, P = .02).