Are reports of cognitive testing among older electroconvulsive therapy recipients clinically valid?
OBJECTIVE
Electroconvulsive therapy (ECT) administration rises in frequency with age, with older depressed adults often showing clinical features predictive of good response. Recent reviews suggest that older people experience few if any long-term cognitive adverse effects after contemporary ECT, despite their increased vulnerability to these. However, the broader clinical validity of research findings is not assured as most studies of ECT-related cognitive effects do not discuss cognitive test nonparticipants. This study examines whether cognitive test participants and nonparticipants are comparable.


METHODS
We recently completed a study of cognition in depressed patients 65 years and older treated with ECT. Only 35% of eligible patients completed neuropsychological testing at 2 time points, the remainder either refusing or unable to consent. To examine whether exclusion of most eligible patients from cognitive testing might have affected the clinical applicability of findings, we compared demographic and clinical characteristics of patients who participated with those who did not based on a subset of patients from our original study.


RESULTS
The 2 patient groups differed in several respects. Most notably, nonparticipants were significantly more likely to be involuntary patients; to refuse food and fluids; and to require treatment with a bitemporal or mixed electrode placement.


CONCLUSIONS
Our findings suggest cognitive test nonparticipants to be more severely psychiatrically unwell than test participants. As their exclusion might bias results and confound understanding of this important ECT-related topic, special mention of participation rates and comparison of participants and nonparticipants is recommended to establish the clinical relevance of future study findings.
From the *School of Psychology and Psychiatry, Monash University, Melbourne, Victoria, Australia; and †Ministry of Health, Kuala Lumpur, Malaysia.
Chris
C
Plakiotis
Loi Fei
LF
Chin
Daniel W
DW
O'Connor
D000058:Accidental Falls / Q000706:statistics & numerical data; D000368:Aged; D000369:Aged, 80 and over; D003071:Cognition / Q000502:physiology*; D003072:Cognition Disorders / Q000175:diagnosis* / Q000209:etiology*; D003865:Major Depressive Disorder / Q000150:complications / Q000453:epidemiology / Q000628:therapy*; D004522:Educational Status; D004565:Electroconvulsive Therapy / Q000009:adverse effects* / Q000295:instrumentation; D005260:Female; D006304:Health Status; D006801:Humans; D008297:Male; D008603:Mental Health; D009483:Neuropsychological Tests; D011618:Psychotic Disorders / Q000150:complications / Q000628:therapy; D011619:Psychotropic Drugs / Q000627:therapeutic use; D015203:Reproducibility of Results; D012737:Sex Factors; D059020:Suicidal Ideation; D014739:Victoria
D011619:Psychotropic Drugs