Other Mental and Behavioral Disorders

The mental and behavioral disorders covered in this section fall into two primary groupings: cognitive disorders and personality disorders.

Cognitive Disorders

Cognitive disorders, including delirium, dementia (often caused by Alzheimer's Disease), and amnesiac disorder, produce a significant impairment of cognition and/or memory representing a marked deterioration from a previous level of functioning. Dementia, one of the major cognitive disorders, produces a loss of intellectual reasoning and cognitive function due to changes in the brain caused by disease or trauma. The changes can affect thinking, memory and reasoning, and may occur gradually or quickly. Cognitive functions that might be affected by dementia include:

  • decision making/judgment
  • memory
  • spatial orientation
  • thinking/reasoning
  • verbal communication
  • neglect of personal safety, hygiene, and nutrition

Excerpts and paraphrasing contributed from "Cognitive Disorders" - PlanetPsych.com and "Alzheimer's and Other Dementias" - Helpguide

Personality Disorders

Personality disorders are generalized, inflexible patterns of inner experience and behavior. These patterns significantly differ from cultural expectations, and begin in adolescence or early adulthood. Personality disorders are long-term, maladaptive patterns of perception, emotional regulation, anxiety, and impulse control. They can lead to enormous personal and societal costs, including lost productivity, hospitalizations, significant unhappiness, imprisonment, and suicide.

Personality disorders are among the least understood and recognized disorders in both psychiatry and general medical care. Ironically, as a group of disorders, they are among the most common of the severe mental disorders, and occur frequently with other illnesses (e.g., substance use disorders, mood disorders, anxiety disorders). Many imprisoned individuals also have a diagnosable personality disorder.

The Diagnostic and Statistical Manual of Mental Disorders (DSM IV, American Psychiatric Association, 1994), organizes personality disorders into three groups, with three or four disorders per group:

Eccentric Personality Disorders: Paranoid, Schizoid, Schizotypal
Individuals with these disorders often appear odd or peculiar, and show these patterns by early adulthood and in various contexts (e.g., work, home, social situations).

Dramatic Personality Disorders: Antisocial, Borderline, Histrionic, and Narcissistic
Individuals with these disorders have intense, unstable emotions, distorted self-perception, and/or behavioral impulsiveness.

Anxious Personality Disorders: Avoidant, Dependent, Obsessive-Compulsive
Individuals with these disorders often appear anxious or fearful, and like the other personality disorders, the generalized patterns described below typically begin in early adulthood, and are present in various contexts.

There also is a diagnosis known as "Personality Disorders Not Otherwise Specified", which is separate from the above three groups of disorders.

This diagnosis would be given for disturbed personality functioning that does not meet criteria for any specific personality disorder, but which leads to distress or harm in one or more important areas of functioning (e.g., social or work-related). The clinician also may give this diagnosis if a specific personality disorder that is not included in the DSM IV Classification seems to apply to an individual (e.g., depressive personality disorder, or passive-aggressive personality disorder; DSM IV, American Psychiatric Association, 1994).

[American Psychiatric Association: Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition. Washington, DC, American Psychiatric Association, 1994.]

Source: "What are Personality Disorders?" - Personality Disorders Foundation (PDF)