Table 1. Baseline characteristics.

Characteristic	No depression	Depression	P value for difference
Number of cases	77	16
Females	33 (43%)	10 (64%)	0.158
Age	52.77±11.32	54.92±13.09	0.499
Comorbidities, n (%)
CAD	1 (1%)	1 (6%)	0.316
COPD	2 (3%)	0 (0%)	1.000
Diabetes	7 (9%)	3 (19%)	0.368
Hypertension	22 (29%)	6 (38%)	0.480
Osteoporosis	1 (1%)	0 (0%)	1.000
Obesity	21 (27%)	5 (31%)	0.747
Smoking	22 (29%)	7 (44%)	0.155
Diagnosis, n (%)
Adjacent segment disease	5 (6%)	2 (13%)	0.407
DDD	65 (84%)	13 (81%)	0.754
Spinal stenosis	35 (45%)	7 (44%)	0.901
Presenting symptom, n (%)
Myelopathy	40 (52%)	10 (63%)	0.443
Radiculopathy	46 (60%)	9 (56%)	0.796
Bowel/bladder dysfunction	7 (9%)	4 (25%)	0.086
Headaches	5 (6%)	0 (0%)	0.583
Motor deficit	44 (57%)	11 (69%)	0.393
Neck pain	63 (82%)	13 (81%)	0.957
Sensory deficit	61 (79%)	11 (69%)	0.366
Functional scores
Preoperative Nurick score	0.92±0.97	1.44±1.41	0.084
ACDF levels	1.64±0.76	2.56±1.36	<0.001*
Follow up, mean ± SD	7.21±5.51	10.55±5.13	0.035*

*, indicates significant result with P<0.05. n, number of patients; CAD, coronary artery disease; COPD, chronic obstructive pulmonary disease; DDD, degenerative disc disease; ACDF, anterior cervical discectomy and fusion; SD, standard deviation.