Comparative Study of Cognitive Function Between Treatment-Resistant Depressive Patients and First-Episode Depressive Patients

Figures & data

Table 1 Comparison of Characteristics Among the TRD, First-Episode Depression, and Normal Control Groups

Characteristics	First-Episode	TRD	Normal Control	F/χ^2	P
	(n=53)	(n=31)	(n=50)
Gender, female, n(%)	23(43.4)	17(54.8)	22(44.0)	1.1952	0.5501
Age, years	32.5±10.9	38.3±13.6	34.0±10.4	2.58	0.080
Education, years	11.4±3.5	12.6±4.1	11.8±3.8	1.00	0.371

Notes: Chi-square test was applied for qualitative data, and one-way analysis of variance with Bonferroni correction was performed for quantitative data.

Abbreviation: TRD, treatment-resistant depression.

Table 2 Comparison of Clinical Characteristics Between the First-Episode Depression and TRD Groups

	First-Episode Depression	TRD	t or u	P
	(n=53)	(n=31)
HAMD score	25.2±5.4	27.2±5.6	1.6159	0.1099
Anxiety/somatization factor	7.0±2.1	7.2±3.2	0.3458	0.7303
Body weight factor	1.2±0.7	1.1±0.7	0.6318	0.5292
Block factor	9.6±4.0	9.7±3.2	0.1187	0.9058
Sleep disturbance factor	4.5±1.5	4.8±1.6	0.8630	0.3906
Duration of illness, months	22.4±16.6	60.3±38.6	6.2474	0.0000
Age at onset, years	32.5±10.9	36.5±12.9	1.5157	0.1334
Number of episodes^a	1	2(1–4)	7.2035	0.0000

Note: ^aListed as median (interquartile range).

Abbreviations: HAMD, Hamilton Depression Rating Scale; TRD, treatment-resistant depression.

Table 3 Comparison of WAIS-RC Between the First-Episode Depression and TRD Groups

	First-Episode Depression	TRD	t	P
	(n=53)	(n=31)
Information	10.86±3.45	11.14±3.58	0.3540	0.7242
Comprehension	11.85±2.85	11.23±2.65	0.9869	0.3266
Arithmetic	9.26±2.32	9.33±2.34	0.1330	0.8945
Similarities	10.95±2.46	10.56±2.26	0.7221	0.4723
Digit span	11.18±2.35	11.25±2.48	0.1291	0.8976
Vocabulary	11.45±2.56	11.12±2.42	0.5815	0.5624
Digit symbol	11.12±3.02	11.75±3.45	0.8751	0.3840
Picture completion	8.96±2.68	8.24±2.35	1.2418	0.2178
Block design	9.82±1.63	9.78±2.14	0.0965	0.9233
Picture arrangement	9.98±2.66	9.46±2.43	0.8920	0.3750
Object assembly	9.84±2.51	9.67±2.33	0.3074	0.7593
VIQ	103.78±12.44	103.36±13.78	0.1435	0.8862
PIQ	97.54±6.22	96.87±8.26	0.4212	0.6747
FIQ	102.43±10.42	101.56±11.56	0.3546	0.7238

Abbreviations: FIQ, full intelligence quotient; PIQ, performance intelligence quotient; TRD, treatment-resistant depression; VIQ, verbal intelligence quotient; WAIS-RC, Chinese revised Wechsler adult intelligence scale.

Table 4 Comparison of Cognitive Function Among TRD, First-Episode Depression, and Normal Control Groups

	First-Episode	TRD	Normal control	F	P	Post hoc^a
	(n=53)	(n=31)	(n=50)
Verbal fluency test (n)	15.4±4.4	15.9±5.6	20.0±6.4	10.20	0.000	A,B<C
Trail Making Test A (s)	64.2±36.5	66.1±28.2	44.0±26.8	7.02	0.001	A,B>C
Trail Making Test B (s)	95.0±56.7	116.8±55.7	68.4±30.4	10.06	0.000	A,B>C; A<B
WCST (n)
Classification number	4.0±1.8	3.2±1.4	5.0±1.6	15.34	0.000	A,B<C; A>B
Total error number	21.5±10.9	22.2±11.9	15.2±8.4	6.41	0.002	A,B>C
Continuing error number	9.7±6.7	12.8±8.6	5.0±3.4	16.10	0.000	A,B>C; A<B
Random error number	12.0±5.9	10.6±6.5	5.2±3.1	23.55	0.000	A,B>C
Tower of Hanoi test
Completed tasks (n)	7.5±2.9	6.3±2.3	10.0±1.3	28.91	0.000	A,B<C
Mean planning time (s)	8.5±6.9	9.3±5.0	5.6±3.2	5.84	0.004	A,B>C
Mean execution time (s)	28.0±15.2	32.5±18.3	21.03±16.5	5.05	0.008	A,B>C
Profile score	44.2±17.7	36.6±17.2	58.7±16.0	18.26	0.000	A,B<C; A>B

Note: ^aThe threshold for significance was p<0.05.

Abbreviations: A, first episode; B, TRD; C, normal control; TRD, treatment-resistant depression; WCST, Wisconsin card sorting test.