Aim: The aim was to investigate whether high catecholamine (CA) excreters would respond less well to a group cognitive behaviour therapy (CBT) treatment for depression than others.
Method: A sample of 70 adults with depression symptoms participated in a 12-week course of group CBT. Participants' 24 hour urinary catecholamine levels at pre-therapy and post-therapy were used to classify them as High (N = 10); Low (N = 33) or Mixed (N = 27) according to a cut-off one standard deviation above a published mean for healthy adults. Beck Depression Inventory (BDI) and cognitions questionnaire (Automatic Thoughts Questionnaire; Beck Hopelessness Scale and Dysfunctional Attitudes Scale) were used.
Results: Repeated measures ANOVA analyses showed an equal rate of mood improvement in all three groups over the course of CBT, despite the fact that the High excreters were on average more depressed throughout the study. Changes in depression symptoms were mirrored by improvements in cognitive measures in the three catecholamine groups.
Conclusion: This study indicates that adults showing a biological marker of depression (elevated catecholamine levels) are equally able to benefit from CBT treatment as adults without this marker.