Table 1. Characteristic features of MDD cohorts and control subjects used in the study.

Postmortem brain samples from all cortical layers of the subgenual cingulate cortex included: control subjects and four major MDD cohorts as described above. Most subjects in the groups are White: controls (75%), single episode (80%), single episode remission (93%), recurrent (85%) and recurrent remission (93%). There were no significant differences between the groups on mean: Age, PMI, pH, RIN and RNA ratio. However, the groups varied in sex ratios, suicide rates and antidepressant use ATOD.

Variables	Controls (I) n=20	MDD-Single episode (II) n=20	MDD-Single episode in Remission (III) n=15	MDD- recurrent episode (IV) n=20	MDD-recurrent episode in Remission (V) n=15
Mean Age	47.9	42.3	47.6	40.9	48.1
Sex (% Male)	90%	80%	53%	65%	67%
Mean PMI	15.35	15.99	12.17	16.8	16.4
Mean pH	6.76	6.62	6.63	6.62	6.61
RNA ratio	1.55	1.62	1.69	1.57	1.42
Mean RIN	8.09	8.08	8.45	8.03	8.03
Suicide (%)	0%	50%	0%	40%	0%
Antidepressant use ATOD (%)	5%	60%	20%	75%	60%

Abbreviations: PMI, postmortem interval; RIN, RNA integrity number; ATOD, at time of death.