Table 2

Results before, after four weeks of L-lysine treatment, and after four weeks of placebo treatment.

Outcome measure

Baseline

Post L-lysine

Post placebo

F value

P-value*


L-lysine blood conc (μmol/l)

196 ± 14 (201 ± 15)

401 ± 74 (363 ± 64)

195 ± 13 (195 ± 10)

7.84 (6.57)

0.024 (0.027)


Symptom severity scales


    PANSS

Positive symptoms

14.6 ± 0.7 (16.0 ± 1.1)

11.9 ± 0.6 (13.5 ± 1.3)

11.6 ± 0.8 (13.4 ± 1.4)

13.11 (12.49)

0.001 (0.000)

Negative symptoms

18.4 ± 2.4 (19.7 ± 2.2)

17.4 ± 2.2 (19.4 ± 2.2)

17.3 ± 2.4 (18.8 ± 2.2)

1.53 (0.69)

0.25 (0.51)

General symptoms

31.3 ± 2.5 (33.5 ± 2.5)

29.5 ± 1.9 (32.3 ± 2.4)

29.1 ± 2.0 (30.9 ± 2.0)

2.14 (2.84)

0.16 (0.09)

Total

64.3 ± 4.2 (69.2 ± 4.7)

58.8 ± 4.0 (65.2 ± 5.4)

58.0 ± 4.5 (63.1 ± 5.0)

13.36 (8.59)

0.001 (0.002)


GAF

43.8 ± 1.8 (42.0 ± 1.9)

46.9 ± 1.6 (45.8 ± 1.6)

44.1 ± 2.3 (42.8 ± 2.1)

4.29 (7.34)

0.035 (0.005)


CGI

3.63 ± 0.18 (3.80 ± 0.20)

3.63 ± 0.18 (3.80 ± 0.20)

3.50 ± 0.27 (3.70 ± 0.26)

1.00 (1.00)

0.39 (0.39)


Depression scale


MADRS

8.50 ± 2.09 (9.10 ± 1.74)

7.50 ± 1.90 (7.90 ± 1.57)

8.38 ± 1.74 (8.40 ± 1.38)

0.54 (0.89)

0.59 (0.43)


Cognitive tests


RAVLT

45.9 ± 4.3 (43.5 ± 4.2)

46.0 ± 4.6 (43.3 ± 4.4)

48.8 ± 3.5 (45.2 ± 4.1)

0.79 (0.48)

0.47 (0.62)


CPT

0.76 ± 0.16 (0.67 ± 0.13)

0.81 ± 0.13 (0.76 ± 0.12)

0.86 ± 0.13 (0.71 ± 0.14)

0.25 (0.21)

0.77 (0.81)


Trail Making Test A

33.8 ± 1.7 (39.2 ± 5.9)

31.3 ± 2.5 (39.9 ± 8.9)

35.3 ± 4.5 (40.8 ± 6.3)

0.44 (0.07)

0.58 (0.93)


Trail Making Test B

77.4 ± 7.2 (134 ± 56)

70.0 ± 5.2 (119 ± 48)

71.3 ± 6.4 (124 ± 50)

0.40 (1.61)

0.68 (0.24)


Letter and number span

8.13 ± 0.90 (7.00 ± 1.03)

9.00 ± 0.66 (8.10 ± 0.82)

9.13 ± 0.92 (8.50 ± 0.95)

0.74 (1.92)

0.50 (0.18)


    Wisconsin Card Sorting

Number of errors

33.9 ± 10.0 (31.9 ± 9.0)

21.0 ± 7.2 (19.7 ± 6.5)

24.4 ± 10.1 (23.2 ± 9.0)

4.91 (5.45)

0.024 (0.016)

Perseverant errors

20.4 ± 7.6 (19.0 ± 6.8)

11.5 ± 5.0 (10.7 ± 4.4)

14.8 ± 8.1 (13.4 ± 7.3)

4.46 (5.00)

0.032 (0.021)

Perseverant answers

23.6 ± 9.6 (21.9 ± 8.7)

13.1 ± 6.6 (21.1 ± 5.9)

17.1 ± 10.3 (15.6 ± 9.2)

4.77 (5.20)

0.026 (0.018)


Mean values outside parenthesis refers to analysis including individuals who did display an increase in blood levels of L-lysine during the L-lysine treatment period (n = 8). Mean values within parenthesis refer to statistical analysis performed on all individuals, that is, also those not displaying increased blood levels of L-lysine during the L-lysine treatment period (total n = 10). *Corrected by the Huynh-Feldt procedure as required.

Wass et al. BMC Medicine 2011 9:40   doi:10.1186/1741-7015-9-40

Open Data