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Moderation of treatment effects by parent-adolescent conflict in a randomised controlled trial of Attachment-Based Family Therapy for adolescent depression Cover

Moderation of treatment effects by parent-adolescent conflict in a randomised controlled trial of Attachment-Based Family Therapy for adolescent depression

Open Access
|Sep 2020
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Figures & Tables

FIGURE 1.

CONSORT flow-chart for study participants

TABLE 1.

Prior distributions and reasoning for choices of prior

ParameterPrior DistributionReasoning
Regression coefficientsNormal (0, 1)Weakly informative prior as the dependent variable is centred on the median score and scaled by twice the median absolute deviation
Error varianceHalf-student’s t (3, 0, 1)Weakly informative prior on the error variance, putting most of the prior weight on errors between 0 and 1, but with heavy tails allowing for a much higher error variance
Random interceptsHierarchical normal prior, with location 0 and a Half-student’s t (3, 0, 1) prior on the scale.Defines random intercepts as deviations from the intercept of the whole sample, and estimates the variance of the random intercepts from the data, with a weakly informative hyperprior
Latent variables for CBQ IRT modelMultivariate normal (0, 1) with an LKJ (2) prior on the standardised covariance matrixDefines the latent variables for parent-adolescent conflict as four correlated Normal (0, 1) variables with a weakly informative prior on the correlation coefficients
Item thresholds for CBQ IRT modelHierarchical normal prior with hyperpriors
Normal (0, 3) for location and Half-students’ t (3, 0 ,1) for scale
Weakly informative hierarchical prior for the item thresholds, as these are interdependent with the defined latent variable
Item discrimination for CBQ IRT modelGamma (2, 0.5)Places most of the prior weight on discrimination between 1 and 5, which is the most probable range for items of an established instrument, but does not rule out higher or lower values
TABLE 2.

Sample characteristics

VariableTreatment arm
ABFT (n=30)TAU (n=30)
Age, years (SE)15.03 (1.35)14.77 (1.36)
Gender, % (n)Female90 (27)83.3 (25)
Dropout, % (n)Excluded7 (2)3.3 (1)
Dropped out10 (3)13.3 (4)
Ethnicity, % (n)Norwegian100 (30)96.7 (30)
Scandinavian0 (0)3.3 (1)
Living with, % (n)Both parents29.6 (8)36.7 (11)
Two home family18.5 (5)13.3 (4)
Father (and any new partner)18.5 (5)13.3 (4)
Mother (and any new partner)33.3 (9)33.3 (10)
Other0 (0)3.3 (1)
Psychiatric comorbidity, % (n)Dysthymia3.3 (1)0 (0)
Any anxiety disorder43.3 (13)46.7 (14)
Obsessive-Compulsive Disorder6.7 (2)6.7 (2)
Externalizing disorder0 (0)13.4 (4)
PTSD3.3 (1)3.3 (1)
Enuresis3.3 (1)6.7 (2)
No comorbidity53.3 (16)46.7 (14)
Depressive symptoms, mean (SD)BDI-II34.23 (7.34)36.21 (9.84)
GRID-HAMD21.87 (4.61)21.92 (4.07)

1 Note. BDI-II = Beck Depression Inventory II Score; GRID-HAMD = Grid-Hamilton Depression Rating Scale Score; Any anxiety disorder includes social phobia, specific phobia, agoraphobia, generalized anxiety disorder, anxiety disorder NOS and obsessive compulsive disorder; Externalising disorder includes oppositional defiant disorder and attention deficit/hyperactivity disorder.

TABLE 3.

Parameter estimates from moderator models

Conflict report and model parameter
MeanSDMedian66% HDI90% HDIESS
Adolescent report of conflict with mother
Intercept0.090.090.090.00 ; 0.17-0.05 ; 0.2411801
Variance of random intercepts0.360.130.370.28 ; 0.500.14 ; 0.561764
Variance of errors0.530.080.530.45 ; 0.590.41 ; 0.652382
Regression coefficients
  Time-0.530.15-0.53-0.65 ; -0.37-0.78 ; -0.2910094
  Treatment0.010.180.01-0.16 ; 0.18-0.29 ; 0.3010608
  Parent-adolescent conflict0.270.290.27-0.01 ; 0.55-0.21 ; 0.767372
  Treatment x time0.070.110.07-0.04 ; 0.17-0.12 ; 0.259108
  Conflict x time0.150.190.15-0.03 ; 0.31-0.16 ; 0.477425
  Treatment x conflict x time-0.690.34-0.70-1.01 ; -0.38-1.25 ; -0.155919
Adolescent report of conflict with father
Intercept0.090.090.090.00 ; 0.18-0.07 ; 0.2412959
Variance of random intercepts0.360.130.380.27 ; 0.510.14 ; 0.582059
Variance of errors0.580.080.570.49 ; 0.640.45 ; 0.692853
Regression coefficients
Time-0.490.16-0.48-0.64 ; -0.34-0.75 ; -0.2311610
Treatment0.000.190.00-0.19 ; 0.16-0.30 ; 0.3111630
Parent-adolescent conflict0.200.310.20-0.07 ; 0.51-0.29 ; 0.7111097
Treatment x time0.040.10.04-0.06 ; 0.13-0.13 ; 0.2110099
Conflict x time0.130.220.13-0.07 ; 0.34-0.24 ; 0.475198
Treatment x conflict x time0.010.400.00-0.38 ; 0.36-0.60 ; 0.704474
Mothers report of conflict
Intercept0.090.090.090.00 ; 0.17-0.05 ; 0.2512613
Variance of random intercepts0.370.120.390.29 ; 0.500.18 ; 0.582008
Variance of errors0.540.080.540.46 ; 0.600.41 ; 0.662488
Regression coefficients
  Time-0.550.15-0.54-0.69 ; -0.4-0.80 ; -0.3010341
  Treatment-0.030.18-0.03-0.21 ; 0.13-0.33 ; 0.2611666
  Parent-adolescent conflict0.190.300.20-0.07 ; 0.51-0.29 ; 0.708534
  Treatment x time-0.080.11-0.08-0.18 ; 0.02-0.26 ; 0.099297
  Conflict x time-0.020.19-0.02-0.19 ; 0.16-0.33 ; 0.286471
  Treatment x conflict x time-0.670.34-0.68-1.01 ; -0.38-1.22 ; -0.116593
Fathers report of conflict
Intercept0.090.090.090 ; 0.17-0.05 ; 0.249540
Variance of random intercepts0.370.120.380.29 ; 0.50.17 ; 0.571651
Variance of errors0.510.080.500.43 ; 0.580.38 ; 0.641740
Regression coefficients
  Time-0.540.16-0.54-0.68 ; -0.38-0.79 ; -0.275165
  Treatment-0.010.18-0.01-0.18 ; 0.16-0.32 ; 0.2610840
  Parent-adolescent conflict0.300.300.300.01 ; 0.59-0.19 ; 0.815729
  Treatment x time-0.030.11-0.03-0.13 ; 0.08-0.21 ; 0.166466
  Conflict x time0.410.240.410.18 ; 0.610.03 ; 0.812780
  Treatment x conflict x time-0.860.44-0.87-1.28 ; -0.46-1.60 ; -0.172701

1 Note. Mean = Posterior mean, SD = Posterior standard deviation, Median = Posterior median, 66% and 90% HDI = 66% and 90% Highest Density Intervals, ESS = Effective Sample Size, estimates the number of independent draws from the posterior distribution

TABLE 4.

Correlation coefficients for latent conflict variables (Posterior means and 90% CI)

Adolescent on fatherAdolescent on motherFather on adolescent
Adolescent on mother0.20 (-0.06 ; 0.46)
Father on adolescent0.59 (0.39 ; 0.79)0.33 (0.04 ; 0.62)
Mother on adolescent0.03 (-0.21 ; 0.27)0.49 (0.28 ; 0.73)0.50 (0.26 ; 0.75)
FIGURE 2.

Model predictions across the range of conflict for different informants

TABLE 5.

Model comparison with leave-one-out cross-validation

Reporter and models comparedDifferenceSE
Time00
Adolescent report of conflict with mother
Time00
Moderator-1.861.36
Treatment-1.870.14
Non-specific predictor-3.910.71
Adolescent report of conflict with father
Time00
Treatment-1.870.14
Non-specific predictor-5.570.40
Moderator-3.740.31
Mother report of conflict
Time00
Treatment-1.870.14
Moderator-3.021.32
Non-specific predictor-4.470.30
Father report of conflict
Time00
Treatment-1.870.14
Moderator-2.341.86
Non-specific predictor-4.540.77

1 Note. Difference = Difference in expected log posterior density to the best-fitting model of those compared; SE = Standard error of the difference

Language: English
Page range: 110 - 122
Published online: Sep 3, 2020
Published in print: Jan 1, 2020
Published by: Center for Evidence-based Psychiatry
In partnership with: Paradigm Publishing Services
Publication frequency: 1 issue per year

© 2020 Erling W. Rognli, Luxsiya Waraan, Nikolai O. Czajkowski, Marianne Aalberg, published by Center for Evidence-based Psychiatry
This work is licensed under the Creative Commons Attribution 4.0 License.