NEW ORLEANS – Electroconvulsive therapy (ECT) in older patients with refractory depression and bipolar disorder has been linked to improvement in some key cognitive measures, allaying fears that the treatment could have a deleterious impact in this patient population, new research shows.
“The current findings suggest older adults of more advanced age — 70-79 vs 50-59 years old, may actually show greater improvement in attention and executive function after undergoing ECT for refractory depression,” study investigator Melanie McArdle, PsyD, McLean Hospital/Harvard Medical School, in Boston, Massachusetts, told delegates attending the American Association for Geriatric Psychiatry (AAGP) 2023 Annual Meeting.
However, “the most significant part of this study is that cognition remained generally stable throughout ECT for all age groups,” McArdle told Medscape Medical News.
The findings are important because although ECT is well-established as an effective treatment for refractory depression, there are concerns around previous data suggesting potential negative effects on cognition, including memory deficits, attention, and executive function, which have been reported to potentially persist for up to 6 months after the treatment.
To examine the potential cognitive effects of ECT in geriatric patients across a range of age groups, the investigators conducted a retrospective cohort study of 770 older adults aged 50-80 years who were referred for ECT at McLean Hospital and received a course of 10 treatments. The majority, 612, had major depressive disorder (MDD), whereas 158 had bipolar disorder (BD).
A total of 347 were in the 50-59 years age group, 281 were 60-69 years old, 122 were between the ages of 70 and 79 years, and 20 were over 80 years.
There were no significant differences in study participants by sex, admission status, electrode placement, education level, or global health rating, and 443 of participants were women. Each age group included significantly more patients with MDD vs BD (P = .02).
As expected, researchers found significant improvement in depressive symptoms across all age groups following the 10-treatment ECT course. Symptom reduction as measured by the Quick Inventory of Depressive Symptomatology (QIDS) ranged from 42% to 57%.
Cognitive changes were measured at baseline and after ECT using the Montreal Cognitive Assessment (MoCA). Overall, researchers found no differences in cognition pre- vs post-ECT in any of the age groups.
However, a closer look at specific cognitive domains showed significantly greater improvements with older age after ECT in terms of the attention index score (P = .019), executive index score (P = .023), and language index score (P = .022); a trend of an age group effect was observed with the orientation index score (P = .057).
Post-ECT cognitive improvements were significantly greater in the 70-79 years age group vs the 50-59 years age group in terms of the attention index score (P = .043) and executive index score (P = .016) but researchers found there were no significant age group differences in the language index score.
Interestingly, patients with BD, irrespective of age, had post-ECT improvements on overall cognitive MoCA scores (P = .01), as well as memory skills, as measured by a delayed recall score which was used in lieu of the Memory Index due to insufficient item-level data (P = .01). In contrast, those with MDD showed slightly declining scores in both metrics (P = .036 and P = .021, respectively).
Of note, the mean changes in all cognitive and memory scores were small across all age groups, with all showing a less than 1-point increase or decrease compared with scores prior to ECT.
A Result of Symptom Reduction?
McArdle speculated that the improvements observed among older patients may be associated with a reduction in depressive symptoms.
“We know that certain cognitive domains, such as executive functioning, can be more vulnerable to aging and depression,” she said. “Therefore, the improvements observed are likely at least partially the result of improvement in depression.”
Evaluation of specific cognitive domains is important in gaining a clearer understanding of ECT’s effects, she added.
“Prior studies utilizing a brief assessment such as the MoCA have focused primarily on total MoCA score rather than domain index scores. Utilizing these domain index scores can provide clinicians with a slightly more granular assessment to monitor cognition throughout a course of ECT,” McArdle said.
Likewise, the stratification by age within the category of geriatric patients is unique.
“Prior studies have demonstrated more pronounced cognitive effects for older adults during ECT, although most studies have failed to examine sub-groups of older adults based on age, as we did in this study,” she added.
Overall, said McArdle, the findings indicate that ECT is safe and with no deleterious impact on cognition in older adults with mood disorders.
Though the results were “broadly similar across age groups in terms of effectiveness on mood and cognitive safety, these findings are preliminary and should be replicated with more sensitive and comprehensive cognitive measures,” she noted.
Commenting on the findings for Medscape Medical News, Cristina Pritchett, MD, a geriatric psychiatry fellow at Emory University School of Medicine in Atlanta, who is involved in ECT research, said that the study adds to existing evidence that it is safe, effective, and well tolerated.
“This is very relevant for all ages, but especially important in the older adult population. The improvements, or minimal impact, in cognition in patients treated with ECT may be related more to the clinical presentation of mood disorders in the elderly, who tend to have a cognitive component. So, as the mood disorder improves, we also expect an improvement in cognition,” said Pritchett.
In terms of the different responses among those with bipolar disorder, Pritchett speculated that baselines differences could have played a role.
“Patients with bipolar disorder may have had a different baseline in cognitive deficits that could potentially improve with treatment more so than patients with MDD. However, it’s evident that patients improved significantly in the QIDS across all age groups, showing a response,” Pritchett said.
Even in instances where cognitive effects do occur, “it’s important to note that most cognitive side effects will improve with time, once patients finish their treatment course,” she added.
The authors and Pritchett had no disclosures.
American Association for Geriatric Psychiatry (AAGP) 2023 Annual Meeting. Presented March 6, 2023.
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