Slater and Roth's (1969) Behavioural Characteristics

These are objective diagnostic indicators

(1) Thought process disorder

• Loose associations (derailment): Wandering from topic to topic, with the wandering often triggered by 'cue' words.
• Word salad: Extremely loose associations producing incoherent speech.
• Neologism: The use of non-words or the novel combination of actual words.
• Clang associations: The linking of words with no relationship to each other, apart from them sounding alike (e.g. rhyming).
• Poverty of content: Talking a lot, but saying little of any meaning.
• Literal interpretation: For example, proverbs
• Thought blocking: Stopping abrupt during speech and failing to remember what comes next.

(2) Disturbances of Affect (emotion)

• Blunted affect: Diminished emotional experience
• Flattened affect: The absence of emotional experience
• Inappropriate affect: Producing the opposite (or different) expected emotion

(3) Psychomoter Disorders (movement)

• Catatonia (Catatonic stupor or excitement): Can range from mutism to agitation
• Stereotypy: Production of repeated movements (e.g. body rocking)

(4) Lack of Volition (movement)

• Apathy: Loss of interest in personal things and/or the environment
• Loss of drive: Lack of motivation to do things