Loose associations are psychiatric issues that occur when patients with thought disorders respond to questions with unrelated answers or sentences or portions of sentences do not follow a logical sequence or relate to each other. This type of disorganized speech can be a symptom of schizophrenia. It can also simply be the result of stress or tiredness.
When loose associations are the result of schizophrenia, the patient's speech patterns seem random and may be based on sounds, rhyming, free association or puns and are extremely difficult to interpret. Also known as derailment, loose associations are used as a diagnosis tool for schizophreniform disorder and schizoaffective disorder as well. Psychiatrists utilize the Thought and Language Index (TLI) scale for categorizing and rating schizophrenic speech, but research in the area has been lacking, and literature offers conflicting ways to categorize speech patterns. Subsets of loose association include "knight's move thinking" (indicating a chess piece can move only in certain directions), loss of goal, where individuals lose track of the purpose of their speech mid-sentence, and tangentiality, where individuals are unable to return to a topic once they have been distracted. The severity of loose association can vary widely between patients, with some experiencing only minor variations in language and others becoming completely unintelligible.