Affective Disorders

Affective Disorders

Cognitive side effects may occur after electroconvulsive treatment (ECT) in depressive disorder patients. Previous studies have been limited by small numbers of cognitive functions assessed. The present study reports the first results from a prospective project monitoring cognitive effects of ECT using a comprehensive neuropsychological test battery and subjective report of everyday cognitive function. Methods: Thirty-one patients with major depressive disorder were assessed with the MATRICS Con- sensus Cognitive Battery (MCCB). Subjective cognitive complaints were described with the Everyday Memory Questionnaire (EMQ). Severity of depression symptoms were assessed with the Montgomery- Åsberg Depression Rating Scale (MADRS). These assessments were performed prior to and 6 weeks after non-standardized ECT. Results:: Compared to baseline, the mean depression severity level was nearly halved and there were significant improvements in mean levels of Speed of Processing, Attention/Vigilance, and Visual Learning 6 weeks after ECT. The other cognitive domains were not altered from baseline. There was no significant change in subjective cognitive complaints. At baseline, there were several significant correlations be- tween the MADRS and MCCB scores. There was no strong association between the EMQ and MCCB scores at either assessment point, but the post-ECT EMQ score was significantly correlated with depression severity. Limitations: Major limitations were low N and lack of uniform ECT procedure. Conclusions: There was significant improvement in Speed of Processing, Attention/Vigilance, and Visual Learning 6 weeks after ECT. Cognitive tests scores were related to severity of depression, but not to subjective memory complaints. Affective Disorders

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1. Introduction

Electroconvulsive therapy (ECT) is a life-saving intervention in treatment-resistant depression, and often results in rapid symp- tom relief. However, fear of memory loss is often cited as the main reason for not consenting to this type of treatment (Fraser et al., 2008). The precise nature, severity, and persistence of such side- effects have been the subject of intense debate. Affective Disorders

A meta-analysis found that a sizable minority of patients report reduced cognitive function, mostly affecting speed of processing, executive function, and episodic memory during the first week after treatment (Semkovska and McLoughlin, 2010). However, 15 days after treatment, these functions were recovered or even im- proved. In the largest and longest-lasting investigation to date, ahn). Affective Disorders

multi-center study of attention, learning, short-term memory, and retrograde amnesia for biographical events in 260 patients, Sack- eim et al. (2007) reported that most cognitive parameters were significantly improved 6 months post ECT relative to pre ECT le- vels. However, reaction time/speed of processing was still com- promised at follow-up. Sustained adverse cognitive effects at fol- low-up were associated with demographic factors such as ad- vanced age, female gender, and lower baseline intellectual function. Affective Disorders


Methodological aspects of ECT may contribute to post-treat- ment cognitive dysfunction. For this reason, sinus wave stimula- tion is no longer recommended, as square pulses result in less cognitive side-effects (Payne and Prudic, 2009). For the same reason, unilateral electrode placement is preferred over bilateral placement (Sackeim et al., 2000; 2007), although clinical char- acteristics of the patient may overrule the attempt to minimize cognitive side effects. Brief pulses usually have a stronger anti- depressive effect compared to ultra-brief stimulation, and recent Affective Disorders

Lack of systematic monitoring has made it impossible to elu- cidate the cognitive side effects of ECT with respect to precise characteristics, severity, and duration (Rasmussen, 2015). There is a large number of studies of cognitive effects of ECT, but they are often limited by the small number of cognitive domains assessed (e.g., Falconer et al., 2010; Porter et al., 2008). A recent post ECT study investigated a broad range of cognitive functions employed participants up to 82 years of age, risking contamination of the results due to early stages of dementia (Bodnar et al., 2015). Thus, there is a need for post ECT studies using comprehensive test batteries assessing a broad range of cognitive functions in younger samples. Affective Disorders

The MATRICS Consensus Cognitive Battery (MCCB) (Nuechter- lein and Green, 2006) consists of 10 tests assessing 7 cognitive domains – Speed of Processing, Attention/Vigilance, Working Memory, Verbal Learning, Visual Learning, Reasoning/Problem Solving, and Social Cognition. The MCCB has very good psycho- metric properties, and is well suited for use in a clinical setting with severely ill respondents (Nuechterlein and Green, 2006). It was developed for the schizophrenia population, but is also used with bipolar disorder (Burdick et al., 2011; Kessler et al., 2014; Lee et al., 2013; van Rheenen and Rossell, 2014), and major depressive disorder (MDD) patients (Murrough et al., 2015). In a baseline article from the current project, we have recently demonstrated that the MCCB is able to separate cognitive functioning of MDD patients and healthy controls, and that the scores of the depres- sion group were generally significantly lower than those of the control group (Mohn and Rund, 2016). Affective Disorders

Although subjective complaints of cognitive impairments may occur after ECT, these subjective reports are not necessarily sup- ported by objective neuropsychological test results (Coleman et al., 1996; Prudic et al., 2000). In general, there is a well-known dis- crepancy between subjective cognitive complaints and objective test performance, both in individuals suffering from mental illness (Moritz et al., 2004) and healthy individuals (van der Elst et al., 2008; Stenfors et al., 2014). We are aware of only one study of the relationship between subjective memory report and neu- ropsychological test scores (Brakemeier et al., 2011). That study found a discrepancy between subjective and objective cognitive function, but was limited by the low number of neuropsycholo- gical tests employed. Affective Disorders

In ill individuals, the above discrepancy may partly be ex- plained by the severity of the depressive symptoms, as depression intensity is correlated with subjective memory failure (Coleman et al., 1996; Prudic et al., 2000). In this study, we will describe the relationship between depression severity, subjective cognitive complaints and MCCB performance.

As previous findings of cognitive changes after ECT are con- flicting, no specific hypotheses were formulated. The following research questions were asked: (1) Is there a change in cognitive function, as assessed with a comprehensive test battery, 6 weeks after ECT? (2) Are the cognitive test scores related to depression severity and subjective memory complaints Affective Disorders