No brain perfusion impairment at long-term follow-up in elderly patients treated with electroconvulsive therapy for major depression

Neurocognitive functioning after electroconvulsive therapy in late-life depression: A 4-year prospective study

OBJECTIVE

Despite the proven efficacy and safety of ECT, there is still concern about the possible cognitive side effects of ECT in older patients. In this study, we aimed to characterize the long-term cognitive effects of ECT in patients with late-life depression (LLD) from before the start until 4 years after the index ECT course.

METHODS

Fourty one patients aged 55 years and older with a unipolar depression, referred for ECT, were included. The neuropsychological test battery was assessed prior to ECT, 6 months, 1 year, 2 years, 3 years, and 4 years after the last ECT session.

RESULTS

We did not find any statistically significant cognitive changes from before the start to 4 years after ending the ECT course. Although we could not detect cognitive changes at group level, we found clinically important differences on an individual level.

CONCLUSION

Cognitive performance in patients with LLD runs a stable course from before the start of ECT until 4 years after the index course. At an individual level, however, both cognitive decline and improvement can be witnessed. Older patients can tolerate ECT and most of them will not experience long-term cognitive side effects.

Long-term neurocognitive functioning after electroconvulsive therapy in patients with late-life depression

OBJECTIVE

There is ongoing concern about the possible negative impact of ECT on neurocognitive functioning in older patients. In this study, we aimed to characterize the long-term cognitive effects of ECT in patients with late-life depression, using an extensive neuropsychological battery.

METHODS

A total of 110 patients aged 55 years and older with unipolar depression, referred for ECT were included. The neuropsychological test battery was assessed prior to ECT and 6 months after the last ECT session.

RESULTS

There were no statistically significant group-level changes from baseline to 6 months post-ECT in any of the neuropsychological measurements. Individual differences in cognitive performance were detected using the Reliable Change Index.

CONCLUSION

Patients with late-life depression do not show deleterious cognitive effects 6 months following an ECT index course, although there are considerable differences at an individual level. Clinicians should not hesitate to prescribe ECT in older patients, as most of these patients will tolerate the treatment course and a small group will even experience a cognitive enhancement. However, clinicians should be aware that a small group of patients can experience cognitive side-effects. Further study is needed to predict which patients have a higher risk of developing cognitive side-effects.

Systematic Review of Cognitive Effects of Electroconvulsive Therapy in Late-Life Depression

OBJECTIVE

Late-life depression (LLD) is known to negatively impact cognition even after remission of mood symptoms. Electroconvulsive therapy (ECT) and newer nonconvulsive electrical and magnetic brain stimulation interventions have been shown to have cognitive effects in patients with neuropsychiatric disorders.

METHODS

This review systematically assessed the effects of ECT on cognition in LLD. EMBASE, Ovid Medline, and PsycINFO were systematically searched through June 2015. The search was limited to publications from peer-reviewed journals in the English language.

RESULTS

A total of 5,154 publications was identified; 318 were reviewed in full text, of which 39 publications related to ECT were included. We focused this review only on ECT because evidence on newer interventions was deemed insufficient for a systematic review. This literature suggests increased rates of interictal and postictal cognitive decline with ECT but no long-term (i.e., 6 months or longer) deleterious effects on cognition. Instead, long-term cognitive outcomes with ECT have been reported as either not changed or improved. This literature favors nondominant unilateral ECT over bilateral ECT for cognition.

CONCLUSION

Published literature on brain stimulation interventions in LLD is mainly limited to ECT. This literature suggests that deleterious effects of ECT in LLD are limited and transient, with better cognitive outcomes with unilateral ECT. There is not enough evidence to fully characterize long-term deleterious effects of ECT or effects of newer brain stimulation techniques on cognition in LLD.

Electroconvulsive Treatment: Hypotheses about Mechanisms of Action

No consensus has been reached on the mode of action of electroconvulsive treatment (ECT). We suggest that two features may aid in the delineation of the involved mechanisms. First, when effective, ECT would be likely to affect brain functions that are typically altered in its primary recipient group, people with severe depression. Central among these are the frontal and temporal lobes, the hypothalamus-pituitary-adrenal (HPA) stress axis, and the mesocorticolimbic dopamine system. Second, the involved mechanisms should be affected for a time period that matches the average endurance of clinical effects, which is indicated to be several days to a few weeks. To identify effects upon frontal and temporal lobe functioning we reviewed human studies using EEG, PET, SPECT, and fMRI. Effects upon the HPA axis and the dopamine system were assessed by reviewing both human and animal studies. The EEG studies indicate that ECT decelerates neural activity in the frontal and temporal lobes (increased delta and theta wave activity) for weeks to months. Comparable findings are reported from PET and SPECT studies, with reduced cerebral blood flow (functional deactivation) for weeks to months after treatment. The EEG deceleration and functional deactivation following ECT are statistically associated with reduced depression scores. FMRI studies indicate that ECT flattens the pattern of activation and deactivation that is associated with cognitive task performance and alters cortical functional connectivity in the ultra slow frequency range. A common finding from human and animal studies is that ECT acutely activates both the HPA axis and the dopamine system. In considering this evidence, we hypothesize that ECT affects the brain in a similar manner as severe stress or brain trauma which activates the HPA axis and the dopamine system and may compromise frontotemporal functions.

Contributing factors to changes of cerebral blood flow in major depressive disorder

BACKGROUND

Results of single photon emission computed tomography (SPECT) regarding mood disorders have been inconsistent. The aim of the study was to elucidate factors contributing to changes in cerebral blood flow in patients with major depressive disorder.

METHODS

A total of 89 consecutive patients diagnosed with major depressive disorder using DSM-IV semistructured interviews were evaluated using single photon emission computed tomography, the 17-item Hamilton Rating Scale for Depression (HRSD), and the Global Assessment of Function (GAF) scale. Nineteen of these patients also underwent the same tests during remission.

RESULTS

Global cerebral blood flow (gCBF) was significantly higher during remission than at the time of enrollment. Significant correlations were seen between gCBF and age, duration of previous episode of depression, and hypochondriasis. However, no correlation was seen between gCBF and HRSD, GAF, severity and duration of depressive episode, or melancholia-type depression. Correlations between gCBF and age were seen only at enrollment and disappeared during remission. No differences in regional cerebral blood flow at any site were seen between time of enrollment and remission for the same patient.

LIMITATION

Analysis that adequately accounts for these factors to changes of cerebral blood flow in major depressive disorder will require a large subject population.

CONCLUSIONS

These results suggest that although there is a decrease in gCBF in major depressive disorder, the level of the decrease is determined by conditions present before episode onset, rather than by the characteristics of the episode itself. The findings also suggest that the correlation between gCBF and age is state-dependent.