Depressive Cognitive Disorders

Abstract

Depressive cognitive disorders, also called Pseudodementia (a term founded by Kiloh in the year 1961), is defined as the cognitive and functional impairment imitating neurodegenerative disorders caused secondary to neuropsychiatric symptoms. Depression with cognitive impairment was given less significance in the past. Though the current practice has given heightening attention to these disorders, as it has been found that the cognitive symptoms associated with depression persist, as residual symptoms (in addition to mood symptoms), and in some cases transform into true neurocognitive dementia over time, these cognitive distortions affect the functioning considerably and increase the risk of recurrence of a depressive disorder in the patients. Since the 1980s, depressive cognitive disorders have been incorporated as part of the reversible and treatable forms of dementia, and in the 1990s, it became more noticeable that depression with the cognitive distortion can be the prodromal phase of neurodegenerative dementia that is irreversible. Recent research studies found that a depressive disorder is correlated with a heightened risk and acts as a strong predictor of developing true dementia. Depression with cognitive impairment nearly always implies incipient dementia and should prompt the professional to begin a relevant diagnostic workup. Based on these findings, the term pseudodementia has been strongly criticized and is considered inappropriate and misleading.According to the diagnostic and statistical manual of mental disorders, fifth edition (DSM-5) cognitive impairment like difficulty thinking, concentrating and decision making are categorized as core symptoms of depression, but a description of reversible dementia secondary to neuropsychiatric disorders’ is not yet considered as a formal diagnosis in the classification system. In the elderly population, two distinct forms of mixed mood and cognitive disruptions are found. They can present with a preliminary mood disorder associated with cognitive disruption, or they can present with a preliminary dementing disorder that is associated with depression. Numerous overlapping characteristics make it difficult to distinguish the two. The connection between depressive disorder and neurodegenerative dementia is complicated and intricate. Cognitive impairment has been found to be persistent even after the depressive phase has remitted. The entire picture becomes more challenging when the depression is part of a bipolar disorder.Mania in the elderly also has atypical presentation as compared to younger patients. They are often misdiagnosed as having dementia (Manic Pseudodementia) secondary to the pressured speech, and hyperkinesis is seen in manic elderly patients.Although in current practice, the term pseudodementia has been considered redundant and misleading, its concept inaugurated a useful principle that every physician should think of depression as an etiology in a patient presenting with symptoms of neurodegenerative dementia and vice verse before formulating the final diagnosis.Over the years, pseudodementia has remained valuable in promoting discussion of numerous treatable neuropsychiatric symptoms, but in recent times its use is strongly condemned in clinical practice. Despite the fact that it helps clinicians to think about treatable and reversible causes of dementing illness, it has major limitations. It implies that the patient has either an organic disorder or a functional impairment, but most of the patients have components of both. It is a descriptive term and should not be used as a diagnostic category. ’cognitive impairment’ has been proposed to be used instead of pseudodementia.

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