Supplemental Material:

Predictions get tougher in older individuals: A longitudinal study of optimism, pessimism and depression.

Social Psychiatry and Psychiatric Epidemiology

Diana Armbruster1, Lars Pieper2, Jens Klotsche3,4, Jürgen Hoyer2

1 Institute of Personality and Individual Differences, Technische Universitaet Dresden, Germany

2 Institute of Clinical Psychology and Psychotherapy, Technische Universitaet Dresden, Germany

3 German Rheumatism Research Center, Leibniz Institute, Berlin, Germany

4 Institute for Social Medicine, Epidemiology and Health Economics, Charité-University Medicine, Berlin, Germany

Correspondence:

Diana Armbruster

E-mail:


Statistical analysis

The categorization of the five age groups was made to ensure comparable sample sizes. Since DETECT is a nationwide clinical epidemiological study of unselected patients consecutively admitted to primary care in Germany, younger adults who are less likely to visit a physician or primary care provider are underrepresented. Thus, the decision was made to (a) group 18-44 year old together and (b) form the next groups along a 10 year interval. Due to too small numbers in the age group of over 84 years olds, these participants had to be excluded. Furthermore, the main focus of this study is on middle-aged and older adults since the association between optimism/pessimism and depression in younger individuals is already well established whereas studies with larger older samples are lacking. Thus, a less fine grained grouping of younger individuals was considered acceptable.

Because of the counterintuitive finding of a positive association between optimism and pessimism in older samples an additional analyses was conducted in order to investigate whether this correlation was due to (a) participants who scored rather high on both traits or due to (b) individuals with low scores in optimism as well as pessimism or (c) both. This analysis was undertaken to investigate the possible occurrence of defensive pessimism in [33,34], a tendency to set unrealistically low expectations in risky situations which in combination with high optimism might be described as “hoping for the best but expecting the worst.

Results

Additional analysis regarding internal consistency of the LOT-R yielded the following results: For uni-dimensional LOT-R scores internal consistency ranged between 0.54-0.59 in the whole sample. Moreover, internal consistency was higher for optimism (0.67-0.70) and pessimism (0.66-0.69) when analysed separately. Interestingly, internal consistency for optimism and pessimism was of comparable size across age groups (i.e.; optimism: 0.65-0.70; pessimism: 0.63-0.72), which stands in stark contrast to the systematically diminishing retest reliability with older age. Findings for uni-dimensional LOT-R are more mixed ranging from about 0.55 in 55-64 year olds to 0.60 in the oldest (75-84 years old) and 0.70 in the youngest sample. In sum, internal consistency is better for separately analyzed optimism and pessimism and in a still acceptable range.

Prevalence of depression varied by age and gender. A diagnosis of depression in accordance with ICD-10 criteria was given when at least three depression symptom questions of the DSQ were answered with "most of the days" and the total DSQ-score was 7 points or higher. Depression was more frequent in females compared to males (6.0% vs. 3.8%; point prevalence). Furthermore, in women there was a continuous increase in depression prevalence over the age groups while in male subjects the highest prevalence rates were found in the age groups of 55-64 yrs. Overall, depression prevalence increased (5.1% to 7.6%) from baseline to follow-up the. Regarding stability of depression 28.8% of all participants who were depressed at baseline (T0) also met diagnostic criteria during follow-up. When men and women were analyzed separately, 32.7% of the female participants with depression at baseline were also depressed during follow-up, while in men 21.5% of the depressed at T0 were depressed during follow-up.


Supplement Table 1 A & B: Comparisons of means and standard deviations in optimism, pessimism and one-dimensional LOT-R scores between (A) male and female participants and (B) the five age cohorts at T0

(A) / Male (ref.) / Female
mean / SD / mean / SD / p-Value / Effect size d
Optimism-Score
Total / 8.78 / 2.66 / 8.58 / 2.74 / 0.023 / 0.07
18 – 44 yrs / 8.77 / 2.46 / 8.72 / 2.49 / 0.771 / 0.02
45 – 54 yrs / 8.62 / 2.60 / 8.54 / 2.59 / 0.679 / 0.03
55 – 64 yrs / 8.78 / 2.63 / 8.53 / 2.79 / 0.157 / 0.09
65 – 74 yrs / 8.85 / 2.79 / 8.65 / 2.92 / 0.252 / 0.07
75 – 84 yrs / 8.93 / 2.77 / 8.34 / 3.13 / 0.048 / 0.20
Pessimism-Score
Total / 5.01 / 2.76 / 4.99 / 2.81 / 0.825 / 0.01
18 – 44 yrs / 4.47 / 2.64 / 4.53 / 2.66 / 0.760 / 0.02
45 – 54 yrs / 4.97 / 2.76 / 5.15 / 2.81 / 0.340 / 0.07
55 – 64 yrs / 5.09 / 2.76 / 5.22 / 2.81 / 0.459 / 0.05
65 – 74 yrs / 5.16 / 2.80 / 5.28 / 2.81 / 0.490 / 0.04
75 – 84 yrs / 5.31 / 2.80 / 4.62 / 3.01 / 0.018 / 0.24
One-dimensional-Score
total / 15.77 / 3.76 / 15.59 / 4.01 / 0.153 / 0.05
18 – 44 yrs / 16.31 / 4.03 / 16.19 / 4.07 / 0.705 / 0.03
45 – 54 yrs / 15.64 / 3.83 / 15.39 / 4.10 / 0.345 / 0.06
55 – 64 yrs / 15.69 / 3.82 / 15.31 / 4.04 / 0.134 / 0.10
65 – 74 yrs / 15.70 / 3.58 / 15.36 / 3.70 / 0.153 / 0.09
75 – 84 yrs / 15.61 / 3.49 / 15.72 / 4.07 / 0.778 / 0.03

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(B) / 18-44 (ref.) / 45-54 yrs / 55-64 yrs / 65-74 yrs / 75-84 yrs
mean / SD / mean / SD / p-Value / Effect size d / mean / SD / p-Value / Effect size d / mean / SD / p-Value / Effect size d / mean / SD / p-Value / Effect size d
Optimism-Score
total / 8.73 / 2.48 / 8.57 / 2.59 / 0.185 / 0.06 / 8.64 / 2.72 / 0.461 / 0.03 / 8.74 / 2.86 / 0.928 / 0.00 / 8.57 / 3.00 / 0.362 / 0.06
male / 8.77 / 2.46 / 8.62 / 2.60 / 0.459 / 0.06 / 8.78 / 2.63 / 0.970 / 0.00 / 8.85 / 2.79 / 0.683 / 0.03 / 8.93 / 2.77 / 0.565 / 0.06
female / 8.72 / 2.49 / 8.54 / 2.59 / 0.250 / 0.07 / 8.53 / 2.79 / 0.244 / 0.07 / 8.65 / 2.92 / 0.667 / 0.03 / 8.34 / 3.13 / 0.095 / 0.14
Pessimism-Score
total / 4.51 / 2.66 / 5.08 / 2.79 / 0.000 / 0.21 / 5.16 / 2.78 / 0.000 / 0.24 / 5.22 / 2.81 / 0.000 / 0.26 / 4.90 / 2.94 / 0.024 / 0.14
male / 4.47 / 2.64 / 4.97 / 2.76 / 0.024 / 0.19 / 5.09 / 2.76 / 0.004 / 0.23 / 5.16 / 2.80 / 0.001 / 0.25 / 5.31 / 2.80 / 0.002 / 0.31
female / 4.53 / 2.66 / 5.15 / 2.81 / 0.000 / 0.23 / 5.22 / 2.81 / 0.000 / 0.25 / 5.28 / 2.81 / 0.000 / 0.28 / 4.62 / 3.01 / 0.686 / 0.03
One-dimensional-Score
total / 16.22 / 4.05 / 15.49 / 4.00 / 0.000 / 0.18 / 15.48 / 3.95 / 0.000 / 0.19 / 15.52 / 3.64 / 0.000 / 0.18 / 15.68 / 3.84 / 0.021 / 0.14
male / 16.31 / 4.03 / 15.64 / 3.83 / 0.045 / 0.17 / 15.69 / 3.82 / 0.053 / 0.16 / 15.70 / 3.58 / 0.047 / 0.16 / 15.61 / 3.49 / 0.065 / 0.18
female / 16.19 / 4.07 / 15.39 / 4.10 / 0.001 / 0.20 / 15.31 / 4.04 / 0.000 / 0.22 / 15.36 / 3.70 / 0.000 / 0.21 / 15.72 / 4.07 / 0.133 / 0.12

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Supplement Table 2 A & B: Comparisons of means and standard deviations in DSQ scores between (A) male and female participants and (B) the five age cohorts at T0, T1 and T2

(A) / Male (ref.) / Female
mean / SD / mean / SD / p-Value / Effect size d
DSQ-Score (T0)
Total / 3.05 / 3.07 / 3.71 / 3.25 / <0.001 / 0.21
18 – 44 yrs / 2.76 / 2.88 / 3.17 / 3.02 / 0.070 / 0.14
45 – 54 yrs / 2.84 / 3.31 / 3.91 / 3.57 / <0.001 / 0.31
55 – 64 yrs / 3.33 / 3.44 / 4.10 / 3.41 / 0.001 / 0.22
65 – 74 yrs / 3.04 / 2.66 / 3.58 / 2.92 / 0.003 / 0.19
75 – 84 yrs / 3.24 / 2.84 / 4.04 / 3.14 / 0.009 / 0.27
DSQ-Score (T1)
Total / 3.00 / 3.09 / 3.48 / 3.21 / <0.001 / 0.15
18 – 44 yrs / 2.22 / 2.61 / 3.05 / 3.15 / <0.001 / 0.28
45 – 54 yrs / 2.82 / 3.23 / 3.54 / 3.36 / 0.002 / 0.22
55 – 64 yrs / 3.12 / 3.21 / 3.91 / 3.42 / <0.001 / 0.24
65 – 74 yrs / 3.20 / 3.02 / 3.40 / 2.84 / 0.321 / 0.07
75 – 84 yrs / 3.65 / 3.15 / 3.58 / 3.17 / 0.824 / 0.02
DSQ-Score (T2)
total / 3.14 / 3.32 / 3.68 / 3.40 / <0.001 / 0.16
18 – 44 yrs / 2.88 / 3.44 / 3.14 / 3.13 / 0.315 / 0.08
45 – 54 yrs / 2.82 / 3.13 / 3.95 / 3.65 / <0.001 / 0.33
55 – 64 yrs / 2.90 / 3.24 / 3.71 / 3.33 / <0.001 / 0.25
65 – 74 yrs / 3.42 / 3.27 / 3.76 / 3.32 / 0.113 / 0.11
75 – 84 yrs / 4.10 / 3.72 / 4.21 / 3.58 / 0.780 / 0.03

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(B) / 18-44 (ref.) / 45-54 yrs / 55-64 yrs / 65-74 yrs / 75-84 yrs
mean / SD / mean / SD / p-Value / Effect size d / mean / SD / p-Value / Effect size d / mean / SD / p-Value / Effect size d / mean / SD / p-Value / Effect size d
DSQ-Score (T0)
total / 3.05 / 2.98 / 3.50 / 3.51 / 0.004 / 0.14 / 3.76 / 3.44 / <0.001 / 0.22 / 3.32 / 2.81 / 0.045 / 0.10 / 3.72 / 3.04 / <0.001 / 0.22
male / 3.05 / 3.07 / 2.76 / 2.88 / 0.758 / 0.03 / 2.84 / 3.31 / 0.022 / 0.18 / 3.33 / 3.44 / 0.216 / 0.10 / 3.04 / 2.66 / 0.101 / 0.17
female / 3.17 / 3.02 / 3.91 / 3.57 / <0.001 / 0.22 / 4.10 / 3.41 / <0.001 / 0.29 / 3.58 / 2.92 / 0.023 / 0.14 / 4.04 / 3.14 / <0.001 / 0.29
DSQ-Score (T1)
total / 2.81 / 3.02 / 3.27 / 3.33 / 0.003 / 0.14 / 3.56 / 3.35 / <0.001 / 0.24 / 3.30 / 2.93 / 0.001 / 0.17 / 3.61 / 3.16 / <0.001 / 0.26
male / 3.00 / 3.09 / 2.22 / 2.61 / 0.015 / 0.20 / 2.82 / 3.23 / <0.001 / 0.30 / 3.12 / 3.21 / <0.001 / 0.34 / 3.20 / 3.02 / <0.001 / 0.51
female / 3.05 / 3.15 / 3.54 / 3.36 / 0.012 / 0.15 / 3.91 / 3.42 / <0.001 / 0.26 / 3.40 / 2.84 / 0.060 / 0.12 / 3.58 / 3.17 / 0.034 / 0.17
DSQ-Score (T2)
total / 3.06 / 3.23 / 3.52 / 3.50 / 0.007 / 0.13 / 3.35 / 3.31 / 0.078 / 0.09 / 3.60 / 3.30 / 0.001 / 0.16 / 4.17 / 3.63 / <0.001 / 0.33
male / 3.14 / 3.32 / 2.88 / 3.44 / 0.837 / 0.02 / 2.82 / 3.13 / 0.929 / 0.01 / 2.90 / 3.24 / 0.053 / 0.16 / 3.42 / 3.27 / 0.002 / 0.35
female / 3.14 / 3.13 / 3.95 / 3.65 / <0.001 / 0.24 / 3.71 / 3.33 / 0.005 / 0.18 / 3.76 / 3.32 / 0.002 / 0.19 / 4.21 / 3.58 / <0.001 / 0.33

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Supplement Table 3: Predictive value (path analysis) of baseline LOT-R optimism, pessimism and one-dimensional score, depression and comorbid disorders to follow-up (T1 and/or T2) depression

Baseline (T0) - Follow-up (T0 and/or T2)
R² / LOT-R Optimism Score T0 - Depression (DSQ) T1/T2 / LOT-R Pessimism Score T0 - Depression (DSQ) T1/T2 / LOT-R one-dimensional Score T0 - Depression (DSQ) T1/T2 / Depression (DSQ) T0 - Depression (DSQ) T1/T2 / Comorbid Disorders T0 - Depression (DSQ) T1/T2
Β / p-value / β / p-value / β / p-value / Β / p-value / β / p-value
Total / 0.18 / -0.14 / <0.001 / 0.14 / <0.001 / -0.21 / <0.001 / 0.22 / <0.001 / 0.21 / <0.001
18 – 44 yrs / 0.22 / -0.16 / 0.006 / 0.26 / <0.001 / -0.35 / <0.001 / 0.14 / 0.001 / 0.17 / 0.001
45 – 54 yrs / 0.20 / -0.10 / 0.055 / 0.19 / 0.002 / -0.22 / <0.001 / 0.22 / <0.001 / 0.21 / <0.001
55 – 64 yrs / 0.22 / -0.18 / 0.001 / 0.19 / 0.001 / -0.28 / <0.001 / 0.25 / <0.001 / 0.16 / 0.001
65 – 74 yrs / 0.14 / -0.17 / 0.003 / 0.08 / 0.210 / -0.18 / 0.002 / 0.23 / <0.001 / 0.19 / <0.001
75 – 84 yrs / 0.19 / 0.01 / 0.887 / -0.07 / 0.396 / 0.05 / 0.473 / 0.26 / <0.001 / 0.33 / <0.001
Male / 0.12 / -0.10 / 0.033 / 0.10 / 0.048 / -0.15 / 0.002 / 0.19 / <0.001 / 0.20 / <0.001
18 – 44 yrs / 0.21 / -0.21 / 0.094 / 0.27 / 0.222 / -0.43 / 0.008 / -0.25 / 0.767 / 0.14 / 0.281
45 – 54 yrs / 0.13 / -0.11 / 0.161 / 0.15 / 0.172 / -0.19 / 0.019 / 0.17 / 0.017 / 0.19 / 0.009
55 – 64 yrs / 0.22 / -0.18 / 0.043 / 0.17 / 0.112 / -0.07 / 0.004 / 0.24 / <0.001 / 0.19 / 0.012
65 – 74 yrs / 0.09 / -0.05 / 0.646 / 0.00 / 0.968 / -0.03 / 0.733 / 0.27 / <0.001 / 0.08 / 0.368
75 – 84 yrs / 0.16 / 0.16 / 0.258 / -0.05 / 0.775 / 0.12 / 0.422 / 0.15 / 0.076 / 0.36 / <0.001
Female / 0.22 / -0.16 / <0.001 / 0.15 / <0.001 / -0.23 / <0.001 / 0.24 / <0.001 / 0.23 / <0.001
18 – 44 yrs / 0.25 / -0.13 / 0.045 / 0.27 / <0.001 / -0.33 / <0.001 / 0.19 / <0.001 / 0.17 / 0.002
45 – 54 yrs / 0.24 / -0.09 / 0.210 / 0.19 / 0.011 / -0.22 / 0.001 / 0.23 / <0.001 / 0.24 / <0.001
55 – 64 yrs / 0.23 / -0.18 / 0.014 / 0.20 / 0.004 / -0.28 / <0.001 / 0.26 / <0.001 / 0.14 / 0.028
65 – 74 yrs / 0.21 / -0.26 / <0.001 / 0.14 / 0.089 / -0.29 / <0.001 / 0.19 / <0.001 / 0.26 / <0.001
75 – 84 yrs / 0.23 / -0.06 / 0.545 / -0.08 / 0.387 / 0.01 / 0.866 / 0.31 / <0.001 / 0.32 / <0.001

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