Pseudodementia: Depressive Cognitive Disorder

Depressive Cognitive Disorders were included in the literature by Kiloh in 1961, under the name “fake dementia” (pseudodementia).

Pseudodementia stands for the cognitive and functional disorders imitating the neurodegenerative disorders that secondarily occur with neuropsychiatric disorders. Its rate of prevalence is 30-45% at advanced ages. The cognitive disorders occurring simultaneously with depression can be permanent, and they can lead to both real dementia and the recurrence of depression at later stages.

As a matter of fact, the term “pseudodementia” has been frequently under discussion in scientific circles, because pseudodementia, which refers to the depression-related cognitive problems at advanced ages, mostly means neurodegenerative dementia that is just beginning. Hence, the term “fake dementia” has drifted away from being a diagnostic concept, and it has been generally used to explain the situation. Instead, the term “depressive cognitive disorder” is recommended.

Etiology of Depressive Cognitive Disorder

While many physicians consider depression to be the root of the symptoms in patients showing the symptoms of neurodegenerative dementia, neurodegenerative dementia is being researched in patients with depressive symptoms.

The long-term inflammation being permanent constitutes the root of cognitive deficiencies. This situation can be observed in two ways in depression: Depressive Cognitive Disorders, or Wernicke’s Pseudodementia, which is more severe.

Depression is one of the biggest reasons for the loss of memory at advanced age groups. Factors causing cognitive impairment in depression:

1. The Neurotransmitter Hypothesis: The functional disorders in the serotonin 5-HT-1B receptors that play part in the treatment of major depressive disorder.
2. Neural Pathways: The memory and the learning process are correlated with the amygdala’s connections in the frontal and temple areas of the brain. Depression causes memory and verbal learning problems by affecting the amygdala and hippocampus in particular.
3. Neuroendocrine Factors:In depression, an increase of cortisol density (hypercortisolemia) causes an impairment of the neurons in the hippocampus.
4. Genetic Factors: A C9ORF72 repeat on the Chromosome was spotted in patients diagnosed with depression-related cognitive disorder. Having been previously found to be in correlation with neurodegenerative dementia, this repeat revealed the genetic connection of depressive cognitive disorder.
5. Psychosocial and environmental factors: Physical or psychological abuse in the past, a weak social support, dismissal, negative life events, and substance abuse lead to an increase in stress, impairment of the HPA axis, and depression.

How to Spot Depressive Cognitive Disorder

1. Laboratory Tests: Following the analysis of the person’s history and mental state, other possibilities that may cause cognitive problems (such as HIV, syphilis, vitamin B12 deficiency, folate deficiency) are eliminated as per the results of the laboratory tests.
2. Neuropsychological Tests:These tests are used to diagnose and explain dementia, and they are also employed in detecting the neurocognitive deficiencies that accompany a number of disorders.
   1. Repeatable Battery for the Assessment of Neuropsychological Status (RBANS): This is a short battery applied individually and designed to measure attention, language, visual spatial-structural skills, and close and distant memories.
   2. Wechsler Memory Scale (WMS): It measures the performance of the patients in seven regions testing the auditory, visual, visual work, instantaneous and delayed memory.
   3. The Clock-Drawing Test is a paper-and-pencil test used to evaluate the visual-motor functions, and planning, sorting, and abstract thinking skills.
   4. The Trail Making Test: This is a test developed to evaluate functions, such as visual conceptualization and visual-motor monitoring, psycho-motor speed, complex visual scanning, simple motor skills, basic sorting skills, visual trail making, mental flexibility, visual attention, focused attention, visual perceptive skills, and administrative functions.
3. Neuroimaging Techniques: Techniques, such as Magnetic Resonance Imaging (MRI) and tomography (PET, SPECT), are used to check the brain abnormalities observed in dementia.
4. Rating Scales: The Cornell Scale for Depression in Dementia (CSDD) is one of the most frequently used scales to scan depression in dementia. Consisting of 19 articles in total, the scale receives information both from the relatives of the patient, and the patient himself. The following are included in the scales it measures:
   1. Mood symptoms: Anxiety, unhappiness, low spirit, short temper.
   2. Behavioral discomfort: Agitated, delay, loss of interest.
   3. Physical symptoms: Loss of appetite and weight
   4. Cyclical function: Daily changes in symptoms
   5. Intellectual discomfort: Suicide, weak self-confidence, etc.

REFERENCES:
– Sekhon, S., & Marwaha, R. (2020). Depressive Cognitive Disorders (Pseudodementia). StatPearls [Internet].
– Marra, H. L. D., Myczkowski, M. L., Memória, C. M., Arnaut, D., Ribeiro, P. L., Mansur, C. G. S., Alberto, R. L., Bellini, B. B., da Silva, A. A. F., Tortella, G., de Andrade, D. C., Teixeira, M. J., Forlenza, O. V., & Marcolin, M. A. (2015). Transcranial magnetic stimulation to address mild cognitive impairment in the elderly: A randomized controlled study. Behavioural Neurology, 2015, Article 287843.
– Emek-Savaş DD, Yerlikaya D, Yener GG (2018). Saat Çizme Testinin İki Farklı Puanlama Sisteminin Türkiye Normları ve Geçerlik-Güvenirlik Çalışması. Turk J Neurol. 24:143-152 DOI:10.4274/tnd.26504.
– Nöropsikolojik Değerlendirmelerde Zeka Testleri – Dikkat Ve Yürütücü İşlev Testleri, Gelişim Testleri – Bellek. Prof. Dr. Özgür Öner.
– Korkmaz NÇ ve Bilek F. (2018). Parkinson Hastalarında Bilişsel (Kognitif) Bozuklukların Değerlendirilmesi. TFD Nörolojik Fizyoterapi Grubu Bülteni. 4(10):1-11.
– Parkinson Hastalarında Bilişsel (Kognitif) Bozuklukların Değerlendirilmesi. Doç. Dr. Nilüfer Çetişli Korkmaz, Uzm. Fzt. Furkan Bilek.