Recent research has acknowledged that impaired cognition is prevalent not only during depressive episodes but also following them, and may limit therapy outcome. In this blog post Jennifer Jordan and Richard Porter describe a study in which they examined the relationship between neuropsychological and depressive symptom change. One hundred and one patients were randomly assigned to schema therapy (ST) or cognitive behaviour therapy (CBT) for major depressive disorder. Results show that despite a significant improvement in depressive symptom severity, there were no significant improvements in neuropsychological functioning in both treatment modalities. The authors discuss this finding and suggest that inclusion of a specific cognitive training component in ST may enhance therapy effectiveness. 

The presence of impaired cognition during depressive episodes is well recognised but the assumption was that these deficits were state dependent and would resolve with the remission of depressive symptoms. As a result, relatively little attention has been paid to these cognitive symptoms in the psychotherapy literature.  More recently though, the focus has shifted to the persistence of cognitive dysfunction even when depression is improved and whether cognitive dysfunction might be a factor limiting our treatment outcomes and long term functioning in those with depression (1, 2).

 Our current paper(3), examined the relationship of neuropsychological and depressive symptom change in  a study of  101 adult outpatients participating in a randomised controlled trial of schema therapy (ST) versus cognitive behaviour therapy (CBT) for major depressive disorder (4). The duration of therapy was one year (6 months of weekly and 6 monthly maintenance sessions).

Neuropsychological testing took place at week 0 and week 16 in the depressed sample (n=69 completed the week 16 assessment) and matched healthy controls (n=58). Expected cognitive deficits were found in the depressed compared to the control group at baseline although only a few domains (verbal learning, memory and executive functioning) were related to depressive severity. Despite a reduction of 50% in depressive symptom severity by 16 weeks, there were no significant improvements in neuropsychological functioning in the depressed group once practice effects (benchmarked against the control group) were taken into account. There were no meaningful differences between CBT and ST, indicating that neither had any specific impact on cognitive dysfunction.

 

This finding of the lack of impact on cognition is not surprising at one level as cognition is not targeted in either CBT or ST. In fact there is surprisingly little evidence regarding the impact of psychotherapies or pharmacotherapy for depression on cognition, although the persistence of cognitive dysfunction despite improvement in depressive symptoms following treatment suggests that these most current treatments for depression are having little impact in this area (1).

 

Specifically addressing cognitive dysfunction might lead to improved longer term functional outcomes (2) however this has yet to be determined empirically.

Some more recent therapy developments such as metacognitive therapy (5) have specific strategies including cognitive training components targeting underlying cognitive dysfunction.  There is preliminary evidence that cognitive training components embedded in psychotherapy might lead to improved cognition (see review 6).  In another study by our team, metacognitive therapy (which has the attention training task) led to discernible changes in cognition by 12 weeks, over and above CBT, and independent of change in depressive symptoms (7).

The attention training task in metacognitive therapy prescribes practice of attentional skills and is designed to enable flexible control of attention, a core aspect of cognitive dysfunction. It also enhances meta-awareness of recurrent negative thinking processes (schema therapy’s “thinking traps”, arguably an essential common factor in all therapies.

 In schema therapy, the key therapy goal is to enable the person to step back from acting reflexively in response to schema modes so that they can respond from a healthy adult perspective. By definition, schemas represent persistent rigid cognitive and emotional biases which are extremely difficult to disengage from.

 Our findings above raise the question:  Could adding a specific cognitive training component to schema therapy speed up and /or enhance the ability to disengage from these unhelpful rigid cognitive processes to enable more adaptive functioning?

 

References

 

1. Bortolato B, Carvalho AF, McIntyre RS. Cognitive dysfunction in major depressive disorder: a state-of-the-art clinical review. CNS Neurol Disord Drug Targets. 2014;13(10):1804-18.

2. Porter RJ, Bowie CR, Jordan J, Malhi GS. Cognitive remediation as a treatment for major depression: A rationale, review of evidence and recommendations for future research. Aust N Z J Psychiatry. 2013;47(12):1165-75.

3. Porter R, Bourke C, Carter J, Douglas K, McIntosh V, Jordan J, et al. No change in neuropsychological dysfunction or emotional processing during treatment of major depression with cognitive–behaviour therapy or schema therapy. Psychol Med. 2015:1-12.

4. Carter JD, McIntosh VV, Jordan J, Porter RJ, Frampton CM, Joyce PR. Psychotherapy for depression: A randomized clinical trial comparing schema therapy and cognitive behavior therapy. J Affect Disord. 2013;151(2):500–5.

5.  Wells A. Metacognitive Therapy for Anxiety and Depression The Guilford Press; 2009.

6. Porter RJ, Douglas K, Jordan J, Bowie CR, Roiser J, Malhi GS. Psychological treatments for cognitive dysfunction in major depressive disorder: current evidence and perspectives. CNS Neurol Disord Drug Targets. 2014;13(10):1677-92.

7. Groves SJ, Porter RJ, Jordan J, Knight R, Carter JD, McIntosh VVW, et al. Changes in neuropsychological function after treatment with metacognitive therapy or cognitive behavior therapy for depression. Depress Anxiety. 2015;32(6):437-44.