Table 4.

Correlates of psychosis onset (n = 30)

Variable	Mean (95% CI)a		P value
	Pre‐psychosis	Diagnosis of psychosis and later
LEDD: (l‐dopa IR) − (DA agonist)	299 [115–483]	513 [372–653]	0.044d
LEDD: (l‐dopa IR) + (DA agonist)	738 [600–876]	752 [579–926]	0.994
MMSE score	26.9 [25.7–28.1]	24.4 [22.2–26.6]	0.002c
Mean akinetic‐rigid motor score	1.2 [0.9–1.4]	1.6 [1.2–1.9]	0.007c
Hoehn & Yahr stage			<0.001b
1	0	0
1.5	0	0
2	18 (60%)	9 (30%)
2.5	5 (17%)	5 (17%)
3	4 (13%)	2 (7%)
4	2 (7%)	8 (27%)
5	1 (3%)	6 (20%)
Dementia: No. (%)	2 (6.7)	+16/−0	<0.001b
Akinetic‐rigid motor subtype: No. (%)	23 (76.7)	+7/−1	<0.001b
Depression: No. (%)	14 (46.7)	+5/−2	1.000
Anticholinergic medication: No. (%)	2 (6.7)	+4/−1	<0.001b
Antipsychotic medication: No. (%)	3 (10)	+11/−2	0.025d

Abbreviations: CI, confidence interval; DA, dopamine; IR, immediate release; LEDD, l‐dopa‐equivalent daily dose; MMSE, Mini‐Mental State Examination.

^aMean group values are provided for continuous variables with 95% CIs in brackets. “Pre‐psychosis” refers to the evaluation in which a diagnosis of psychotic disorder was not made; and “post‐psychosis” refers to the subsequent evaluation in which psychosis was present. The median length of the intervals between these evaluations was 2.2 years, with an interquartile range of 2.0 to 2.6 years (the full range was from 0.9 to 6.5 years). For count variables at diagnosis, the number of new positive cases/medication users (+) is compared with the number of patients who discontinued the corresponding medication or who carried the corresponding diagnosis at the pre‐psychosis evaluation but not at the time of psychosis (−). Significance estimates were produced using tests appropriate for paired data: the Wilcoxon signed‐rank test (continuous and ordinal variables) and the McNemar test (count variables).

^b P < 0.001.

^c P < 0.01.

^d P < 0.05.