Organic Mental Illnesses

Organic Mental Illness
Organic Mental Illnesses

Most of us take a well functioning mental processes for granted. We take “the thousand natural shocks that flesh is heir to,” process the madness, and resiliently survive. However, mental faculties are delicately balanced, and under harsh conditions, may falter. Historically, people have viewed mental disorders as a matter of choice—a consequence of behaviors. Certainly, we have progressed. We now accept that many of these disorders are caused by structural lesions in the brain. These disorders are considered organic mental illnesses.

Declining mental functions may occur for a variety of reasons. When there is a physical cause for a mental disorder, either from disease or injury, these disorders are listed as organic. The term organic mental disorders is used to describe all diagnostic groups in which an organic brain disease or a known physical injury is the main cause for the mental symptoms.

Three Classes of Mental Disorders

Organic Mental Disorders

Organic mental disorders can be subdivided into two subcategories:

  1. Mental disorders due to brain diseases (Alzheimer’s disease, Huntington’s disease, brain cancer, etc…), brain injuries (car accidents, traumatic brain injury, etc…) or developmental brain disorders (ADHD, learning disorders, autism, etc…).
  2. Mental disorders due to psychoactive substance use

Psychotic Disorders

The second category of mental disorders is designated for the disorders with psychosis. These disorders fall under three subcategories:

  1. Paranoid or delusional disorder
  2. Manic-depressive disorder
  3. Schizophrenia 

Non-organic, Non-psychotic Disorders

The third category is composed of all mental disorders that do not have organic or psychosis as the basis of the disorder (Xu, 2009). Historically, these disorders have been referred to as neurosis. Included in third category are the neurotic diseases formerly known as axis II disorders, mostly known as the personality disorders. These disorders are seen as functional disorders because they serve a functional purpose for dealing with harsh environments. They serve a protective purpose working as a defense mechanism against threats to the ego.

Examples of Organic Mental Illnesses

A notable example of an organic mental disorder from psychological history is the case of Phineas Gage. While working on a blasting crew in 1848, due to an error, an accidental explosion thrust his tampering iron through his brain, largely removing most of his left prefrontal cortex.

​Gage survived the accident but suffered from extreme emotional lability after the accident. The traumatic brain injury impacted Gage’s ability to regulate emotions. Reportedly, towards the end of Gages life he began to regain many of the Emotional Regulation skills he initially lost during the accident.

My dad is another excellent example of an individual with an organic mental disorder. I mentioned him in a number of articles over the years (e.g. Stoically AloofAn Example of Kindness). My dad suffers from Alzheimer’s disease. Once a retired engineer, he now is completely dependent on others for his care. Alzheimer’s disease severely diminishes his mental capacity.

All Disorders Have an Organic Basis

While only certain mental disorders are considered as organic mental illnesses, all mental states and conditions are organic in basis. All mental disorders “are rooted in neural activity” (Kihlstrom, 2005).

While categories and subcategories serve a purpose, they have limitations. William James wrote, “most cases are mixed cases, and we should not treat our classifications with too much respect” (2008). Basically, we must accept the unknown inherent in complexity. Certainly, we can point to some of the causes; but there is always more to the story.

Most mental disorders have both a biological and environmental component. The biological givens create certain vulnerabilities that may activate a disorder when exposed to overwhelming stress. The diathesis stress model theorizes that “biological or genetic traits (diatheses) interact with environmental influences (stressors) to produce disorders such as depression, anxiety, or schizophrenia” (Murphy, 2021).

A Few Final Words

While we may be more apt to express empathy with those suffering from an organic mental illness, we should compassionately and patiently reach out to all those suffering from disorders. In conclusion, organic mental illnesses are just a label. We, no matter what the cause, should treat those suffering with respect. Whether a disorder is a coping mechanism gone haywire, or a organically inherited disease doesn’t matter. A human being is struggling, experiencing pain, and needs acceptance. 


James, William (1902/2008). The Varieties of Religious Experience. Arc Manor.

Kihlstrom, J. (2005). Dissociative Disorders. Annual Review of Clinical Psychology, 1, 227-253.

Murphy, T. Franklin (2021) Diathesis Stress Model. Psychology Fanatic. Published 9-7-2022. Accessed 12-19-2022.

Xu, Y. (2009). The Third Category of Mental Disorders. “Culture, Medicine and Psychiatry”, 33(4), 496-500.

2 thoughts on “Organic Mental Illnesses”

  1. Pingback: Brief Psychotic Disorder - Psychology Fanatic

  2. Pingback: Emotional Dysregulation

Leave a Reply

%d bloggers like this: