Major Depressive Disorder with Psychotic Features May Lead to Misdiagnosis of Dementia

Abstract

Major depressive disorder (MDD) with psychotic features is relatively frequent among patients with greater depressive symptom severity and is associated with a poorer course of illness and more functional impairment than MDD without psychotic features. Multiple studies have found that patients with psychotic mood disorders demonstrate significantly poorer cognitive performance in a variety of areas than those with nonpsychotic mood disorders. The Mini Mental State Examination (MMSE) and the Dementia Rating Scale (DRS-2) are widely used to measure cognitive functions in research on MDD with psychotic features. Established total raw score cut-offs of 24 on the MMSE and of 137 on the DRS-2 in published manuals suggest possible global cognitive impairment and dementia, respectively. Limited research is available on these suggested cut-offs for patients with MDD with psychotic features. We document the therapeutic benefit of electroconvulsive therapy (ECT), which is usually associated with short-term cognitive impairment, in a 68-year-old woman with psychotic depression whose MMSE and DRS-2 scores initially suggested possible global cognitive impairment and dementia. Over the course of four ECT treatments, this patient’s MMSE scores progressively increased. After the second ECT treatment, the patient no longer met criteria for global cognitive impairment. With each treatment, depression severity, measured by the 24-item Hamilton Rating Scale for Depression, improved sequentially. Thus, the suggested cut-off scores for the MMSE or DRS-2 in patients with MDD with psychotic features may in some cases produce false-positive indications of dementia.

The Role of Baseline Cognitive Function in the Neurocognitive Effects of Electroconvulsive Therapy in Depressed Elderly Patients

“…However, our findings are also consistent with literature describing marked improvement of cognitive function in some of these patients (Pier et al, 2012;Wagner et al, 2011), as the cognitive course within the group differed markedly. CIND patients who reverted to normal might have been among those whose cognitive function was temporarily impaired by major depression (McClintock, Husain, Greer, & Cullum, 2010); thus, their baseline performance on the standardized neuropsychological tests did not reflect their cognitive abilities in remission.…”

“…Cognitive impairment in the elderly often persists after efficacious treatment of the depression (Bhalla et al, 2009;Butters et al, 2008;Nebes et al, 2003). However, in some individuals, indications of severe cognitive impairment at the baseline are not present after a course of ECT, if remission was achieved (Pier, Briggs, Pasculli, & Kellner, 2012;Stoudemire, Hill, Morris, & Dalton, 1995;Stoudemire et al, 1991;Wagner, McClintock, Rosenquist, McCall, & Kahn, 2011).…”

Baseline cognitive function does not predict the treatment outcome of electroconvulsive therapy (ECT) in late-life depression

“…At baseline, indications of mild cognitive impairment were found in 27 (41.5%) patients, whereas 15 (23.1%) were no longer categorized as impaired after the ECT course. Similarly, a misdiagnosis of dementia has been reported in elderly patients with MD before they were successfully treated with ECT (Pier et al, 2012;Wagner et al, 2011). However, several studies have demonstrated that despite the improvement observed in some patients after treatment (Dybedal et al, 2015), cognitive functioning remained impaired at the group level in elderly depressed patients who presented with cognitive impairment at baseline (Butters et al, 2000;Sarapas et al, 2012).…”

Successful Electroconvulsive Therapy for Major Depression Misdiagnosed as Alzheimer Dementia

“…Our report corroborates a study demonstrating that ECT may produce long-term cognitive improvement, 4 as well as a report questioning the validity of the Dementia Rating Scale and MMSE in assessing patients with comorbid psychotic depression and cognitive impairment. 5 …”