Negative self-schemas and the onset of depression in women.

Thinking sad, feeling sad?Jonathan Evans, Jon Heron, Glyn Lewis, Ricardo Araya, Dieter Wolke and the Avon Longitudinal

Study of Parents and Children (ALSPAC)

University of Bristol, UK

What is cognitive theory of depression?

• Aaron T Beck a psychoanalyst.

• Previously - depressed moods arise because of subconscious processes conflict, deficit.

• Cognitive theory reverses – the feeling thoughts.

• Thoughts are not just a symptom of depression they are causal.

Two forms

• Automatic negative thoughts

• Schema

What are schema?

‘stable characteristics of personality that cause depression by distorting the selection, encoding, organisation and evaluation of environmental stimuli’ (Gotlib & Hammen, 1992)

Are schema latent?

‘Even though these attitudes (or concepts) may not be prominent or even discernible at a given time they persist in a latent state like an explosive charge ready to be detonated by an appropriate set of conditions’

Beck 1969

Evidence for cognitive theory

• Haaga et al (1991)– Causal elements lead to hypotheses:

• Stability

• Events specificity

• Onset

• Recurrence

• Cognitive therapy for depression effective.

Evidence continued

• Evidence for negative schema (dysfunctional attitudes) and onset lacking.

• Explanation when not depressed subjects need to be primed eg. Teasdale – differential activation

• No large population based longitudinal study looking at onset of depression in relation to negative schema.

Methods

• We studied women recruited for ALSPAC• Avon Longitudinal Study of Parents and Children

– 14 000 women recruited in pregnancy • Depression measure - EPDS and ‘personality’

IPSM at 18 weeks repeated depression measure at 32 weeks pregnancy

• We chose from IPSM those items which related to negative self schema:

I avoid saying what I think for fear of being rejected.

If others knew the real me they would not like me.

If other people knew what I am really like they would think less of me.

I always expect criticism.

I don’t like people to really know me.

My value as a person depends enormously on what others think of me.

• For the main analyses - those women who were not depressed (EPDS <12) at 18 weeks of pregnancy.

• Investigated the onset of depression 14 weeks later by EPDS at 32 weeks of pregnancy.

• Logistic regression with NSS unit score and dividing into tertiles for scale

Women scoring in the highest tertile NSS c.f. lowest two tertiles

(combined)

• High scorers more likely to have children, a family history of depression, a previous history of severe depression and were older.

Highest tertile Lowest two tertiles

P

N % N % Total

3066 35.9 5474 64.1

Clinical variables

EPDS Score 0 to 9 2291 74.7 4912 89.7 Score 10 to

12 775 25.3 562 10.3

Maternal history of depression

Missing 141 4.60 220 4.0 0.001 Yes 625 20.4 949 17.3 No 2300 75.0 4305 78.6

Paternal history of depression

Missing 206 6.7 341 6.23 0.001 Yes 247 8.0 330 6.03 No 2613 85.2 4803 87.7

Own history of severe depression

Yes 260 8.84 270 5.09 < 0.001 No 2680 91.2 5038 94.9

Demographic variables

Maternal age at delivery

Teen 68 2.22 166 3.03 0.001 20-34 2621 85.6 4758 87 35+ 374 12.2 547 10

Parity 0 1299 42.9 2468 45.7 0.020 1 1112 36.7 1944 36 2 or more 615 20.3 988 18.3

Onset of depression

• Of those with two EPDS measures (i.e. 9083) 8540 (94%) also completed at least the six selected items of comprising the negative self-schema measure and of these 736 (8.6%, 95% c.i. 8.0% to 9.2%) had onset of depression between 18 weeks and 32 weeks of pregnancy

Onset risk by NSS score

• The risk of depression onset increased with each unit increase in negative self-schemas score, odds ratio 1.16 (95% c.i. 1.14 to 1.19, p < 0.001).

• Adjusting for EPDS depression score at baseline attenuated the association, odds ratio 1.07 (95% c.i. 1.05, 1.09 p < 0.001).

• There was little further change when also adjusting for other potential confounders, odds ratio 1.07 (95% c.i. 1.05, 1.10 p < 0.001, n = 7845).

N Prevalence of depression (%)

OR [95% CI] Adj1 OR [CI] Adj2 OR [CI]

Negative self schema score

1st tertile (0-2) 2702 4.8 1.00 reference 1.00 reference 1.00 reference

2nd tertile (3-5) 2772 7.0 1.48 [1.18, 1.86] 1.16 [0.91, 1.46] 1.24 [0.96, 1.60]

3rd tertile (6-18) 3066 13.4 3.04 [2.48, 3.73] 1.56 [1.26, 1.93] 1.60 [1.27, 2.02]

P < 0.001 P < 0.001 P < 0.001

Sample size 8540 N = 8540 N = 8540 N = 7845

Odds ratio of becoming depressed by tertiles of negative self-schema score unadjusted and adjusted for depression score at 18 weeks and then adjusted for other confounders.

1Adjustment for EPDS at baseline 18 weeks of pregnancy.2 Adjustment for past history of depression, parental history of depression, smoking, housing tenure, crowding in household, marital status, education, age, car ownership, unemployment in partner and parity and also time between measures.

Residual confounding

• Additional adjustment for mood using the Crown-Crisp Index no substantial difference.– adjusted odds ratio for onset of depression for

those in the highest tertile of the negative self-schemas score 1.42 (95% confidence interval 1.11 to 1.80, p = 0.008, n = 7540).

Differential activation

• Is a lowering of mood required to prime women in order to elicit NSS?

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Six item IPSM t1 Six item IPSM t2 Six item IPSM t3

Category of negative self-schemas and EPDS at 18 weeks

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Interaction in log regression model

Although the association of negative self-schemas scale score was stronger at higher levels of subthreshold EPDS score this interaction was not statistically significant within the logistic regression model, Likelihood Ratio test, chi squared = 0.053, p=0.819.

• Are these just early symptoms?

Table 4. Relationship between negative self-schema score measured at 18 weeks of pregnancy and onset of depression reported at various time points thereafter. Sample size refers to the number of subjects who were not depressed at baseline or any subsequent assessments before the outcome was measured.

Outcome Sample size Onset of depression Not

depressed

Odds Ratio for Negative self-schema*

(continuous)

Odds Ratio for

EPDS 18 (continuous)

EPDS (32 weeks of pregnancy) 8539 736 (8.6%) 7803 1.07 [1.05, 1.10] 1.36 [1.32, 1.40]

EPDS (8weeks postpartum) 7249 320 (4.4%) 6929 1.07 [1.04, 1.11] 1.21 [1.17, 1.26]

EPDS (8 months postpartum) 6505 196 (3.0%) 6309 1.10 [1.05, 1.14] 1.20 [1.14, 1.26]

EPDS (21 months postpartum) 5719 207(3.6%) 5512 1.11 [1.07, 1.16] 1.16 [1.11, 1.21]

EPDS (33 months postpartum) 5008 212 (4.2%) 4796 1.10 [1.06, 1.14] 1.18 [1.13, 1.23]

* adjusted for depressive symptom score at 18 weeks of pregnancy. All p-values are < 0.001.

Conclusion

• Findings support the hypothesis that individuals who have negative self schema are vulnerable to the onset of depression.

• These negative self schema are not latent and do not require low mood to prime them ie their effect is the same at all levels of depression.

• It is worth studying origins of NSS as understanding these may help inform primary preventive programme for depression.