The Prevalence of Depression in Dementia Syndrome

It is estimated that up to 90% of patients with dementia are affected by behavioral and psychiatric symptoms during the course of the disease. The aim of this study was to investigate the prevalence of depression in dementia and mild cognitive impairment (MCI), the use of benzodiazepines and antidepressants among them and the impact of former education on their cognitive decline.

In the study we have enrolled 100 patients with clinical diagnoses of either MCI or dementia, as was established by a single cognitive neurology subspecialist. All patients were assessed during their regular outpatient follow-ups in the University Clinical Center Zagreb, Croatia, in the period between November 2019 and March 2020. Using the patients' medical history the demographic data, disease characteristics, history of other diseases, use of medications, Mini-Mental State Examination (MMSE) and the data on radiological brain examinations were obtained. The statistical tests were used depending on the distribution of variables.

In total, there were 34 patients diagnosed with dementia and 66 diagnosed with MCI. The diagnosis of depression before the onset of dementia or MCI was established in 11% and it has developed in further 20% after cognitive deterioration, which represents an increase of 81.81%. The total prevalence of depression in the study group is thus 31%.The proportion of patients taking benzodiazepines was 26% and antidepressants 17%.The MMSE scores were significantly lower in patients with Alzheimer's disease than in patients with vascular MCI or dementia. Generally, MMSE values correlated significantly with the duration of education.

Depression is a frequent accompanying disease of dementia that aggravates already complex clinical picture and greatly diminishes the quality of life of the patient. It is important to monitor changes in a patient's cognitive decline and presence of psychiatric symptoms in order to give medical professionals a better chance to alleviate the complex issues that arise during the management of this specter of diseases.