Table 1. Baseline Characteristics.

Participant and scale characteristics	Mean (SD)
	Lithium aspartate (n = 24)	Placebo (n = 26)
Participant
Age, y	62.3 (14.3)	55.0 (13.7)
Sex, No. (%)
Male	14 (58)	14 (54)
Female	10 (42)	12 (46)
Race and ethnicity, No. (%)a
Hispanic White	2 (8)	0
Non-Hispanic White	22 (92)	26 (100)
Received any COVID-19 vaccinations, No. (%)	20 (83)	25 (96)
Duration of PCC, mo	17.4 (9.9)	17.5 (10.4)
Scale
FSS-7b	39.5 (10.9)	43.0 (8.0)
BFSSc	37.3 (9.7)	35.3 (10.9)
Sum of FSS-7 and BFSS	76.7 (17.2)	78.4 (13.7)
Insomnia Severity Scaled	13.0 (7.2)	14.4 (6.9)
Generalized Anxiety Scale-2e	1.7 (1.7)	2.3 (1.7)
Beck Depression Inventory-IIf	14.8 (7.1)	17.2 (6.6)
Short Form-12 Health Survey: Physical Component scoreg	33.9 (9.7)	34.0 (11.2)
Short Form-12 Health Survey: Mental Component scoreh	43.4 (9.0)	43.4 10.9)
Well-Being Scalei	5.0 (1.9)	4.5 (2.0)
Digit Symbol Substitution Testj	47.2 (8.9)	50.2 (14.6)
5 Object Registrationk	4.6 (0.6)	4.7 (0.6)
5 Object 3-Minute Recalll	4.0 (0.9)	4.4 (0.8)
Headache Bother Questionnairem	2.7 (1.2)	2.7 (1.3)
Body Pain Bother Questionnairen	3.5 (1.2)	3.1 (1.4)
Sense of Smell and Taste Impairment Scaleo	2.3 (1.5)	1.6 (0.9)

Abbreviations: BFSS, Brain Fog Severity Scale; FSS-7, Fatigue Severity Scale-7; PCC, post–COVID-19 condition.

^a Race and ethnicity were assessed to help with interpretation of the generalizability of the results across races and ethnicity. All races were assessed but 100% of enrolled patients were White.

^b FSS-7 score range, 7 to 49; higher scores indicate more severe symptoms.

^c BFSS score range, 7 to 49; higher scores indicate more severe symptoms.

^d Insomnia Severity Index; range 0-28, with higher scores indicating more severe insomnia.

^e Generalized Anxiety Disorder Scale-2 score range, 0 to 6; higher scores indicate more severe symptoms.

^f Beck Depression Inventory-II score range, 0 to 63; higher scores indicate more severe symptoms.

^g Short Form-12 Health Survey: Physical Component scores greater than 50 indicate better-than-average health-related quality of life.

^h Short Form-12 Health Survey: Physical Component scores greater than 50 indicate better-than-average health-related quality of life.

ⁱ Well-Being Scale scores range from 0 to 10; higher scores indicate greater sense of well-being.

^j Digit Symbol Substitution Test score range, 0-93; higher scores indicate better cognition.

^k 5 Object Registration score range, 0-5, higher scores indicate better cognition.

^l 5 Object 3-Minute Recall score range, 0-5, higher scores indicate better cognition.

^m Headache Bother Questionnaire score range, 1-5; higher scores indicate worse symptoms.

ⁿ Body Pain Bother Questionnaire score range, 1-5; higher scores indicate worse symptoms.

^o Sense of Smell and Taste Impairment Scale score range, 1-5; higher scores indicate worse symptoms.