Table 2.
Demographic and health characteristics in the prior MDD medication treatment failure subgroup across MDD severity levels
| Characteristic | Minimal/mild MDD (n = 517) | Moderate MDD (n = 244) | Mod severe MDD (n = 187) | Severe MDD (n = 129) |
|---|---|---|---|---|
| Age, mean (SD), years | 50.2 (15.2)a | 46.0 (15.7)b | 44.3 (15.8)b | 42.9 (15.2)b |
| Female,* n (%) | 407 (78.7)a | 197 (80.7)a | 145 (77.5)a | 101 (78.3)a |
| Race and ethnicity, n (%) | ||||
| African American | 16 (3.1)a,b | 5 (2.1)a | 14 (7.5)b | 10 (7.8)b,c |
| American Indian | 2 (0.4)a | 5 (2.1)a | 1 (0.5)a | 1 (0.8)a |
| Asian | 11 (2.1)a | 2 (0.8)a | 5 (2.7)a | 4 (3.1)a |
| Hispanic | 30 (5.8)a | 21 (8.6)a | 16 (8.6)a | 16 (12.4)a |
| Multiracial | 21 (4.1)a | 13 (5.3)a | 6 (3.2)a | 2 (1.6)a |
| White | 436 (84.3)a | 198 (81.2)a,b | 144 (77.0)a,b | 96 (74.4)b |
| Other† | 1 (0.2)a | 0 (0.0) | 1 (0.5)a | 0 (0.0) |
| Marital status: single/not living with partner, n (%) | 261 (50.5)a | 119 (48.8)a | 110 (58.8)a | 76 (58.9)a |
| Less than university education, n (%) | 188 (36.4)a | 89 (36.5)a | 66 (35.3)a | 37 (28.7)a |
| Annual household income, n (%) | ||||
| < $25,000 | 95 (18.4)a | 51 (20.9)a,b | 59 (31.6)b,c | 46 (35.7)c |
| $25,000 to < $50,000 | 149 (28.8)a | 64 (26.2)a | 54 (28.9)a | 39 (30.2)a |
| $50,000 to < $75,000 | 91 (17.6)a | 43 (17.6)a | 27 (14.4)a | 18 (14.0)a |
| > $75,000 | 164 (31.7)a | 72 (29.5)a | 45 (24.1)a,b | 21 (16.3)b |
| Declined to answer | 18 (3.5)a | 14 (5.7)a | 2 (1.1)a | 5 (3.9)a |
| Unemployed,‡ n (%) | 261 (50.5)a | 127 (52.1)a,b | 100 (53.5)a,b | 82 (63.6)b |
| Long- or short-term disability, n (%) | 53 (10.3)a | 40 (16.4)a | 29 (15.5)a | 38 (29.5)b |
| Health insurance type, n (%) | ||||
| Coverage through employer | 151 (29.2)a | 60 (24.6)a,b | 43 (23.0)a,b | 17 (13.2)b |
| Medicare | 145 (28.1)a | 57 (23.4)a | 44 (23.5)a | 38 (29.5)a |
| Medicaid or MediCal | 53 (10.3)a | 38 (15.6)a,b | 34 (18.2)b | 22 (17.1)a,b |
| Coverage through spouse/partner | 60 (11.6)a | 31 (12.7)a | 14 (7.5)a | 12 (9.3)a |
| Coverage through employer of parent/legal guardian | 22 (4.3)a | 17 (7.0)a,b | 18 (9.6)b | 11 (8.5)a,b |
| Coverage through State Health Exchange | 26 (5.0)a | 15 (6.2)a | 15 (8.0)a | 7 (5.4)a |
| Coverage purchased directly by participant | 24 (4.6)a | 6 (2.5)a | 6 (3.2)a | 2 (1.6)a |
| Veterans Administration or CHAMPUS | 10 (1.9)a | 4 (1.6)a | 5 (2.7)a | 5 (3.9)a |
| TRICARE | 8 (1.6)a | 1 (0.4)a | 1 (0.5)a | 1 (0.8)a |
| Unsure | 2 (0.4)a | 2 (0.8)a | 0 (0.0) | 3 (2.3)a |
| No insurance | 16 (3.1)a | 13 (5.3)a,b | 7 (3.7)a,b | 11 (8.5)b |
| Do not exercise, n (%) | 216 (41.8)a | 138 (56.6)b | 96 (51.3)a,b | 72 (55.8)b |
| Current smoker, n (%) | 68 (13.2)a | 34 (13.9)a | 39 (20.9)a | 25 (19.4)a |
| BMI, mean (SD), kg/m2 | 31.1 (8.5)a | 31.4 (8.7)a,b | 31.9 (9.4)a,b | 33.7 (9.1)b |
| CCI, mean (SD) | 0.84 (1.4)a | 0.91 (1.4)a | 0.80 (1.4)a | 1.03 (1.4)a |
| PHQ-9 Score (0–27), mean (SD) | 5.3 (2.7)a | 11.9 (1.4)b | 16.9 (1.4)c | 23.0 (2.4)d |
| GAD-7 Score (0–21), mean (SD) | 4.6 (4.0)a | 8.8 (4.6)b | 11.4 (4.8)c | 15.2 (4.9)d |
| Number of comorbid mental health diagnoses, mean (SD) | 1.6 (1.5)a | 2.3 (1.6)b | 2.6 (1.8)b,c | 3.0 (1.9)c |
| Diagnosed with other mental health disorders, n (%) | ||||
| Anxiety | 324 (62.7)a | 190 (77.9)b | 152 (81.3)b | 113 (87.6)b |
| GAD | 217 (42.0)a | 149 (61.1)b | 112 (59.9)b | 87 (67.4)b |
| Social anxiety disorder | 63 (12.2)a | 68 (27.9)b | 63 (33.7)b,c | 57 (44.2)c |
| PTSD | 64 (12.4)a | 45 (18.4)a,b | 35 (18.7)a,b | 39 (30.2)b |
| Panic disorder | 57 (11.0)a | 47 (19.3)b | 42 (22.5)b | 37 (28.7)b |
| OCD | 41 (7.9)a | 29 (11.9)a,b | 25 (13.4)a,b | 23 (17.8)b |
| ADD | 29 (5.6)a | 21 (8.6)a | 20 (10.7)a | 11 (8.5)a |
| ADHD | 18 (3.5)a | 11 (4.5)a | 14 (7.5)a | 11 (8.5)a |
| Phobias | 10 (1.9)a | 7 (2.9)a,b | 13 (7.0)b,c | 12 (9.3)c |
| Dementia | 0 (0.0) | 0 (0.0) | 1 (0.5)a | 0 (0.0) |
| Time since diagnosis, mean (SD), years | 19.0 (11.4)a | 17.2 (10.7)a | 17.5 (10.4)a | 16.5 (11.7)a |
| Total number of depressive symptoms,± mean (SD) | 2.6 (0.7)a | 2.8 (0.6)a,b | 2.9 (0.5)b | 2.9 (0.5)b,c |
| Depressed mood and other emotional problems, n (%) | 483 (95.8)a | 229 (96.2)a | 180 (97.3)a | 118 (93.7)a |
| Mental changes, n (%) | 271 (53.8)a | 153 (64.3)b | 112 (60.5)a,b | 80 (63.5)a,b |
| Sleep pattern changes, n (%) | 234 (46.4)a | 123 (51.7)a | 90 (48.7)a | 61 (48.4)a |
| Currently using prescribed medication for MDD, n (%) | 517 (100.0) | 244 (100.0) | 187 (100.0) | 129 (100.0) |
| Medications currently being used, n (%) | ||||
| SSRI/SNRIs | 456 (88.2)a | 200 (82.0)a | 161 (86.1)a | 114 (88.4)a |
| Bupropion | 101 (19.5)a | 60 (24.6)a | 50 (26.7)a | 31 (24.0)a |
| Atypical antipsychotics/antipsychotic combination pills§ | 47 (9.1)a | 16 (6.6)a | 20 (10.7)a | 13 (10.1)a |
| TCA/TeCAs | 10 (1.9)a | 5 (2.1)a | 3 (1.6)a | 10 (7.8)b |
| Other antidepressants¶ | 18 (3.5)a | 6 (2.5)a | 7 (3.7)a | 6 (4.7)a |
| Mood stabilizers | 10 (1.9)a | 10 (4.1)a | 7 (3.7)a | 4 (3.1)a |
| MAOIs | 0 (0.0) | 0 (0.0) | 0 (0.0) | 0 (0.0) |
| Medication adherence (0–100 VAS scale), mean (SD) | 94.9 (14.4)a | 91.0 (20.2)b | 88.6 (21.3)b | 85.0 (25.4)b |
Superscripts in the same row represent pairwise comparisons between cohorts; values with different superscripts are significantly different at P < 0.05; values without superscripts were not included in the test. In addition to pairwise comparison, one-way ANOVA was used to compare across groups for the following variables: age, CCI, BMI, time since diagnosis, PHQ-9 scores, GAD-7 scores, total number of depressive symptoms, number of comorbid mental health diagnoses, and medication adherence (all P < 0.001 except for BMI, time since diagnosis [P < 0.05], and CCI [P > 0.05]); all other variables (e.g., sex, race and ethnicity) were first compared across all groups using chi-square (all P < 0.001 except for health insurance type, TCA/TeCAs [P = 0.001], race and ethnicity, OCD [P < 0.01], ADHD, mental changes [P < 0.05], sex, marital status, university education, employment, smoking status, ADD, dementia, depressed mood and other emotional problems, sleep pattern changes, SSRI/SNRIs, bupropion, antipsychotics, other antidepressants, and mood stabilizers [P > 0.05])
ADD attention deficit disorder, ADHD attention deficit hyperactivity disorder, BMI body mass index, CCI Charlson Comorbidity Index, GAD generalized anxiety disorder, GAD-7 Generalized Anxiety Disorder 7, MAOI monoamine oxidase inhibitor, MDD major depressive disorder, Mod Severe moderately severe, OCD obsessive compulsive disorder, PHQ-9 Patient Health Questionnaire-9, PTSD post-traumatic stress disorder, SD standard deviation, SNRI serotonin and norepinephrine reuptake inhibitor, SSRI selective serotonin reuptake inhibitor, TCA tricyclic antidepressants, TeCA tetracyclic antidepressants, VAS visual analogue scale
*Sex was self-reported by participants as male or female
†Other referred to participants who reported their race as “some other race or origin”
‡Participants who reported their employment status as one of the following were considered unemployed: homemaker, retired, student, long-term disability, or short-term disability, not employed but looking for work, and not employed and not looking for work
±Of those currently experiencing symptoms
§Includes the combination pills amitriptyline/perphenazine and fluoxetine/olanzapine
¶Other antidepressants included mirtazapine and nefazodone