Serum concentrations of mood stabilizers are associated with memory, but not other cognitive domains in psychosis spectrum disorders; explorative analyses in a naturalistic setting

International Journal of Bipolar Disorders

Table 2 Serum concentration of mood stabilizers, and neuropsychological test scores

	BD		SCZ
	Median	IQR	Median	IQR
Serum concentrations of mood stabilizers^a
Lamotrigine (µmol/L)	10.4	13.1	8.4	10.4
Valproate (µmol/L)	304	336	386	428
Lithium (mmol/L)	0.58	0.27	0.60	0.46
Neuropsychological test scores
Verbal learning
CVLT Total A1-5	56.0	15.0	48.0	15.3
Verbal memory—immediate recall
Logical memory test immediate recall	24.0	10.0	20.5	10.5
Verbal memory—short term delayed recall
CVLT short delay free recall	13.0	5.0	11.0	5.5
Verbal memory—long term delayed recall
CVLT long delay free recall	13.0	4.0	12.0	5.3
Logical memory test delayed recall	22.0	11.0	16.0	11.5
Attention
Digit span test forwards	6.0	2.0	6.0	2.0
Working memory
Digit span test backwards	4.0	1.0	4.0	2.0
Executive function
Verbal fluency test letter^b	43.0	18.3	33.0	25.0
Verbal fluency test category^c	44.0	12.0	35.5	16.3
CW 3 inhibition	56.0	18.3	64.0	28.3
CW 4 inhibition/switching	60.0	18.0	65.0	29.5
Processing/psychomotor speed
Digit symbol coding test	67.0	21.0	53.0	24.3
CW Stroop (color naming)	31.0	9.0	38.0	13.0

SCZ schizophrenia and other psychotic disorders, BD bipolar disorder, IQR interquartile range, CVLT California verbal learning test, CW color-word
^aThere were no significant differences in serum concentrations of mood stabilizers between BD and SCZ
^bScores were missing for 6% of subjects in the SCZ group
^cScores were missing for 8% of subjects in the SCZ group