While **Pathological Lying** (clinically known as *pseudologia fantastica*) is a recognized condition, there is no formal medical diagnosis called "Pathological Truth." However, psychology and neurology do describe behaviors that function as its opposite—compulsive or rigid honesty that becomes damaging to the individual's social life.

If we look at the spectrum of truth-telling, here is how "Pathological Truth" compares to Pathological Lying:

### 1. Pathological Lying (The Distortion)
*   **Goal:** The person lies compulsively to create a more interesting, flattering, or exciting version of reality. They are often driven by an internal need to escape boredom or inadequacy.
*   **The "Disease":** It is an addiction to deception. The person blurs the line between fact and fiction so much they may eventually believe their own lies.
*   **Social Impact:** It destroys trust because everyone around them knows the reality has been falsified.

### 2. "Pathological Truth" or Hyper-Honesty (The Rigidity)
While there is no single name for this, several conditions result in a compulsion to speak only the truth, often to the detriment of social relationships:

*   **Disinhibition Syndrome:** Often caused by damage to the frontal lobes of the brain (which controls social filtering). These individuals lose the ability to suppress what they think. They don't lie; they simply have no filter, leading to "brutal honesty" that shocks or offends people (e.g., telling a friend their outfit is ugly because it objectively looks bad).
*   **Scrupulosity (a form of OCD):** Some individuals suffer from extreme anxiety regarding morality. They become obsessively driven to be precise and truthful, fearing that even the smallest "white lie" (like saying you liked a meal when you didn't) is a moral failure. This can make interactions exhausting for everyone involved because they constantly correct minor details or confess irrelevant personal thoughts.
*   **Neurodivergence (ASD):** Individuals with Autism Spectrum Disorder often struggle to understand the social utility of "polite lies." To them, truth is binary: something is either a fact or it isn't. They aren't being "pathological"; they simply prioritize objective reality over social comfort.

### 3. Perpetual Truth (The Philosophical Trap)
If you are referring to **"Perpetual Truth"** in a philosophical sense—that there are absolute, unchangeable facts that override human perception—trying to live by this as a rule is often considered a form of rigidity.

*   **The Contrast:** Pathological Lying is about *creating* reality (making things up). "Pathological Truth" is an inability to navigate the *social* layer of reality (not knowing when a little fiction helps people get along).
*   **The Outcome:** Just as pathological liars isolate themselves because they are viewed as unreliable, obsessively truthful people can isolate themselves because they are viewed as rigid, cold, or lacking in empathy.

In summary: **Pathological Lying** is an addiction to fantasy, while **"Pathological Truth"** (usually linked to OCD or disinhibition) is an inability to tolerate ambiguity or social fiction.