Category of mental disorders including dementia
Pro Research Analysisby 
Searched over 200M research papers
Classification of Dementia Within Mental Disorders
Dementia is classified as a mental disorder, but its categorization has evolved over time. In the ICD-10, dementia was broadly defined as a "mental disorder" and included under "organic mental disorders," focusing on chronic or progressive brain disease leading to cognitive decline. The ICD-11 now places dementia under "neurocognitive disorders," with a more specific, symptom-based definition requiring marked impairment in at least two cognitive functions. This shift reflects a move toward a more precise and operational diagnostic system, distinguishing dementia from other mental and cognitive disorders such as intellectual disability and delirium .
Types of Dementia and Their Relationship to Mental Disorders
Dementia is a syndrome, not a single disease, and includes several subtypes: Alzheimer’s disease, vascular dementia, dementia with Lewy bodies, and frontotemporal dementia. These subtypes are characterized by chronic and progressive loss of memory and other cognitive functions, with diagnosis based on clinical history and mental status examination 69. Dementia is distinct from mild cognitive impairment, delirium, and lifelong intellectual disabilities, which are not classified as dementia 69.
Mental Disorders as Risk Factors for Dementia
A strong body of research shows that various mental disorders—including schizophrenia, bipolar disorder, major depression, anxiety, post-traumatic stress disorder (PTSD), and sleep disorders—are associated with an increased risk of developing dementia later in life 1357+2 MORE. The risk is particularly pronounced for severe mental illnesses such as schizophrenia and bipolar disorder, but is also significant for depression and anxiety 1357+2 MORE. These associations are evident for both Alzheimer’s disease and other types of dementia 1357+2 MORE.
Dementia Subtypes and Co-occurring Psychiatric Disorders
The prevalence of psychiatric disorders varies across dementia subtypes. For example, frontotemporal dementia and vascular dementia are associated with higher rates of mood, anxiety, and substance use disorders, as well as suicidal behavior, compared to Alzheimer’s disease, which has the lowest prevalence of co-occurring mental health disorders . This highlights the importance of recognizing and managing psychiatric symptoms in patients with different types of dementia .
Implications for Prevention and Clinical Practice
Mental disorders are now recognized as modifiable risk factors for dementia, suggesting that early identification and treatment of psychiatric conditions could help reduce the risk of cognitive decline and neurodegenerative disease in later life 5810. Clinicians are encouraged to monitor cognitive function in patients with severe mental disorders and to consider dementia in the differential diagnosis when adults present with memory difficulties or unexplained functional decline 168.
Conclusion
Dementia is a category of mental disorder now classified under neurocognitive disorders, with several subtypes including Alzheimer’s disease, vascular dementia, and others. A wide range of mental disorders—especially severe psychiatric illnesses—are associated with an increased risk of developing dementia. Understanding these relationships is crucial for early intervention, prevention, and comprehensive care for individuals at risk.
Sources and full results
Most relevant research papers on this topic
High Occurrence of Psychiatric Disorders and Suicidal Behavior Across Dementia Subtypes.
Mental health disorders are highly prevalent in dementia patients, with higher rates in FTD, VD, LBD, and MD, emphasizing the need for mental health support and prevention in these subtypes.
DOI