What Makes a Belief a Delusion? Delusions, Thought Disorder, the TALD Scale

An analysis of how to clinically distinguish true delusions from overvalued ideas, culturally shared beliefs, and other forms of psychosis.

Delusions in psychiatry: how do you tell a true delusion from an overvalued idea, a culturally shared belief, or substance- or mood-related psychosis? We walk through practical interview questions, thought disorder (TALD) concepts, and a real-world style case formulation. 💡Anti-depressant Course: psycho.farm/psychofarm-course 📖 PsychoFarm's Treating Depression Book: a.co/d/3M0uFui ================ Follow PsychoFarm: 🔴SUBSCRIBE ► youtube.com/c/Psychofarm?sub_confirmation=1 🧠Mental Health Resources: psycho.farm/services-4 ➡ Substack: psychofarm.substack.com/ ➡Apple Podcasts: podcasts.apple.com/us/podcast/psychofarm-podcast/id176654449… ➡Spotify: open.spotify.com/show/5kqD1sD0EtWNYopWT5MbGs ================ 0:00 Intro and Clarifying Last Episode 1:40 When Tapering Is Dangerous 2:24 How to Define Psychosis 4:10 Psychosis vs Schizophrenia 5:39 Why “Loss of Reality” Is Too Broad 8:16 Transition to Delusions 9:44 Thought Disorder and TALD Scale 13:31 How to Interview Delusions 18:32 Substance, Mood, and Personality Psychosis 22:41 What Makes a Belief a Delusion 31:50 Case Example: Lion’s Mane Belief 43:06 Treating Delusions vs Overvalued Ideas How do you actually evaluate a “delusion” in the room, especially when the belief could be plausible, culturally reinforced, or tied to mood or substances? In this episode, we share a practical approach to psychosis language, why “fixed false belief” is often insufficient, and the interview questions that help clarify origin, certainty, flexibility, and function. We also use the TALD framework to expand beyond the usual linear vs circumstantial vs tangential model of thought disorder, then apply everything to a case vignette where a single supplement becomes the explanation for an entire life collapse. Educational and clinically focused. Delusions in psychiatry: how do you tell a primary delusion from an overvalued idea, a culturally shared belief, or a psychotic state tied to mood or substances? In this episode, Dr. Malzberg and Dr. Fu focus on practical clinical interviewing, careful documentation language, and the real-world edge cases where “loss of contact with reality” is too broad to be useful. WHAT WE CLARIFY ABOUT PSYCHOSIS • Why a one-line definition can mislead • Psychosis vs schizophrenia-spectrum processes • Where bipolar disorder with psychotic features fits, and why it can feel “fuzzy” in practice THOUGHT DISORDER BEYOND THE 3-LEVEL MODEL We discuss the Thought and Language Disorder Scale (TALD) as a way to broaden your mental model of disorganized speech and thought beyond “circumstantial → tangential → word salad,” including subjective and objective phenomena you can actually listen for in session. A PRACTICAL DELUSION INTERVIEW (QUESTIONS THAT WORK) When you’re unsure what you’re hearing, try: • How did you come to believe this? • What experiences made you more certain? • What could change your mind? • Who have you t