Relationship between depression and diabetes in pregnancy: A systematic review

Table 2 Outcomes of included studies involving women with pre-existing type 1 or type 2 diabetes

First authorstudy design	Definition/measures of depression	Timing of depression measures	Overall nSubgroups, n	Main outcomes/findings
Berger[25] Retrospective	EPDS ≥ 13 or did not answer “No” to self-harm question	Within 4 d after delivery	Unselected, n = 322 History of mental illness, n = 215	Prevalence of pre-existing DM did not differ between women with or without postpartum depression in either the unselected group or the group with history of mental illness Of 5 women with pre-existing DM, none had depression
Callesen[30] Prospective, cohort	HADS ≥ 8	8 wk gestation	n = 148 Type 1, n = 118 Type 2, n = 30	Women with DM and depression were more likely to have preterm delivery (54% vs 16%, P = 0.003) and less likely to be nulliparous (23% vs 54%, P = 0.03) than women with DM without depression
Dalfra[34] Prospective	CES-D ≥ 16	3rd trimester and 8 wk after delivery	n = 245 Type 1, n = 30; No DM, n = 39	Mean (SD) CES-D scores at 3rd trimester were 19.1 (9.6) among women with Type 1 DM and 18.0 (8.7) among women without DM (P = 0.67) The severity of depressive symptoms increased from the 3rd trimester to after delivery in women with Type 1 DM [estimated mean difference in CES-D score (95%CI): 6.6 (2.9-10.2)], but decreased in women without DM [2.7 (-5.9-0.5), P < 0.0001 between groups]
Jovanovic[39] Retrospective, claims database	ICD-9 codes 311, 296.2, 296.3, 300.4, 301.12, 309.1	During pregnancy and/or within 3 mo after delivery	n = 839792 Type 1, n = 1125 Type 2, n = 10136 No DM, n = 773751	Prevalence of depression was 5.2% and 8.3% among women with type 1 and type 2 DM, respectively Prevalence of concurrent type 1 DM and depression was 0.006% Prevalence of concurrent type 2 DM and depression was 0.086% Relative risk (95%CI): of depression in women with type 1 DM vs women with no DM was 1.16 (0.86-1.56) Relative risk (95%CI): of depression in women with type 2 DM vs women with no DM was 1.84 (1.70-2.00)
Katon 2011[41] Cross-sectional analysis of prospective cohort	PHQ-9	3rd trimester	n = 2398 Pre-existing DM (type NR), n = 226; No DM, n = 1747	Prevalence (95%CI): of probable major depression among women with pre-existing DM was 5.8% (2.7%-8.8%) by PHQ-9 score, 8.9% (5.1%-12.6%) by antidepressant use, and 13.3% (8.8%-17.7%) by either PHQ-9 or antidepressant use, compared with the prevalence among women without DM [PHQ-9: 4.1% (3.2%-5.1%); antidepressants: 6.2% (5.1%-7.3%); PHQ-9 and antidepressants: 9.6% (8.2%-11.0%)] After adjusting for demographic characteristics, chronic medical conditions, and pregnancy variables, pre-existing DM was not associated with major or any antenatal depression (P value not reported)
Katon 2014 (PPD)[42] Retrospective, hospital database	PHQ-9	2nd or 3rd trimester and 6 wk after delivery	n = 1423	Prevalence of pre-existing DM was higher in women with PPD (14.5%) than in women without PPD (6.9%) (P = 0.02) Of 104 women with pre-existing DM, 12 (11.5%) had PPD Pre-existing DM was a risk factor for postpartum depression [OR (95%CI): 1.98 (1.12-3.52)] (P = 0.02) Prevalence of concurrent pre-existing DM and depression was 0.84%
Kozhimannil[46] Retrospective cohort	ICD9 codes 296.2, 296.3, 300.4, 301.12, 309.1, and 311	During the 6 mo before and up to 1 yr after delivery	n = 11024 With pre-existing DM (type NR), n = 311 (taking insulin, n = 57); no DM, n = 10367	Prevalence of depression in women with pre-existing DM taking insulin was 14.0% vs 16.1% among women with pre-existing DM not taking insulin (P value not reported)
Levy-Shiff[66] Prospective	BDI	2nd trimester	n = 153 Pre-existing DM, n = 53 (type NR) No DM, n = 49	No significant difference in depression during 2nd trimester between pre-existing DM [mean (SD) BDI score 6.17 (5.16)] and controls [6.59 (5.88)] (P≥ 0.05) For sample as a whole, higher levels of cognitive assessment of pregnancy as a challenge was associated with lower depression (P < 0.05) Among women with pre-existing DM, higher levels of medical support were associated with lower levels of depression (P < 0.01)
Mei-Dan[50] Retrospective, health administration database	ICD-9, ICD-10CA, and/or DSM-IV (ICD codes NR)	Within 5 yr before pregnancy	n = 437941 With pre-pregnancy depression, n = 3724 No known mental illness, n = 432358	Prevalence of DM (type NR) within 1 year before the index pregnancy was significantly higher in women with pre-pregnancy depression (3.4%) than in women with no known mental illness (1.2%) (P value NR) Prevalence of pre-existing DM and pre-pregnancy depression was 0.029%
Moore[67] Prospective	Depression Adjective Checklist; Perceived Stress Scale	3rd trimester	n = 131 Pre-existing insulin-dependent DM, n = 73 High risk of preterm birth, n = 48 Low risk of preterm birth, n = 25	White women with DM who were tested at a private clinic had higher Depression Adjective Checklist and Perceived Stress Scale scores than any other group (variables of white vs black, private vs public medical centre, DM vs low or high risk of preterm birth) (P value not reported)
Ragland[54] Prospective, cross-sectional	BDI > 13	During pregnancy	n = 50 Type 1 DM, n = 8 Type 2 DM, n = 20	Mean BDI score was 10.0 among women with type 1 DM and 17.1 among women with type 2 DM No women with type 1 DM and 12 (60%) women with type 2 DM had BDI > 13
1Räisänen 2013[56] Retrospective, registry review	ICD10 codes F31.3, F31.5, F32-34	Up to 6 wk postpartum or a history of depression	n = 511422	Prevalence of pre-existing DM: 8.4% of women without any depression (n = 492103), 11.1% of women with history of depression but not PPD (n = 17881), 14.6% of women with PPD but no history of depression (n = 431), and 13.3% of women with both history of depression and PPD (n = 1007) (P ≤ 0.001)
1Räisänen 2014[55] Retrospective, registry review	ICD10 codes F31.3, F31.5, F32-34	At hospital discharge after delivery	n = 511938	Prevalence of pre-existing DM (type NR): 8.4% of women without any depression (n = 493037), 10.9% of women with history of depression but not during pregnancy (n = 14781), 11.6% of women with depression during pregnancy but no history of depression (n = 2189), and 13.6% of women with both depression during pregnancy and history of depression (n = 1931) (P ≤ 0.001) Depression during pregnancy was not associated with pre-existing DM [adjusted OR (95%CI): = 1.10 (0.93-1.31)]
Singh[59] Retrospective	BDI ≥ 10; self-reported medical history	During pregnancy	n = 152 History of depression, n = 39 No history of depression, n = 113	Type 2 DM was significantly more common in women with history of depression than in women with no history of depression (P < 0.05) Of 39 women with history of depression, 5 (13%) had type 1 DM, and 19 (49%) had type 2 DM Of 113 women with no history of depression, 18 (16%) had type 1 DM, and 28 (25%) had type 2 DM
Sundaram[62] Prospective, exploratory	Survey of PPD diagnosis; survey of symptoms based on PHQ-2	Postpartum	Up to 61733 pregnancies	In analysis of data from 22 states, pre-existing DM was not a significant predictor of PPD symptoms [OR (95%CI): 1.16 (0.78-1.59), n = 45669, P = 0.39) or diagnosis [OR (95%CI): 1.31 (0.45-3.06), n = 5924, P = 0.56)] In analysis of data from 2 states that included both PPD symptoms and diagnosis on the survey, pre-existing DM was a significant predictor of PPD diagnosis [OR (95%CI): 5.65 (1.72-15.37), n = 2136, P < 0.01)]

¹The Räisänen et al 2013 and 2014 publications use the same database within the same time period (2002-2010) and, therefore, the study populations are almost identical. BDI: Beck Depression Inventory; CES-D: Center for Epidemiologic Studies Depression scale; CI: Confidence interval; DM: Diabetes mellitus; DSM-IV: Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition; EPDS: Edinburgh Postnatal Depression Scale; HADS: Hospital Anxiety and Depression Scale; ICD: International Classification of Disease; ICD-10CA: enhanced version of International Classification of Diseases, 10^th revision, for use in Canada; NR: Not reported; PHQ: Patient Health Questionnaire; PPD: Postpartum depression; SD: Standard deviation.