Table 1

Participant demographics

Characteristic^*	Patients with TRD n = 60	Healthy controls n = 30	Statistics^†
Age, yr	45.37 ± 11.85	45.63 ± 13.16	t₈₈ = 0.096, p = 0.92
Female, %	40	40	χ²₈₈ = 0.0, p = 1.0
Education, yr	15.3 ± 1.9	14.7 ± 2.1	t₈₈ = 1.50, p = 0.14
MMSE score	29.1 ± 1.4	28.5 ± 3.3	t₈₈ = 1.38, p = 0.17
Age at onset of TRD, yr	36.0 ± 15.6	—	—
Duration of illness, yr	10.9 ± 9.2	—	—
MADRS score	32.1 ± 7.1	—	—

MADRS = Montgomery–Åsberg Depression Rating Scale; MMSE = Mini-Mental State Examination; TRD = treatment-resistant depression.
↵* Values are mean ± standard deviation or %.
↵† p values are uncorrected.