Childhood-Onset Fluency Disorder (Stuttering)

Childhood-Onset Fluency Disorder (also known as Stuttering) is a disorder characterized by a disturbance in the normal fluency and time patterning of speech that is inappropriate for an individual's age. The disorder is characterized by frequent repetitions or prolongations of sounds or syllables. Other speech deficits include: (1) single words that are broken up (e.g. - pauses within a word), (2) audible or silent blocks (i.e. - filled or unfilled pauses in speech), (3) circumlocutions (i.e. - word substitutions to avoid problematic words), (4) words produced with excess physical tension, and (5) monosyllabic whole-word repetitions (e.g., 'He-he-he-he is here“).


Childhood-onset fluency disorder develops by age 6 in 80% to 90% of individuals. The average age of onset is from 2 to 7 years. The risk of stuttering in 1st-degree biological relatives of individuals with childhood-onset fluency disorder is 3 times the risk of the general population.

Criterion A

Disturbances in the normal fluency (i.e. - dysfluencies) and time patterning of speech that are inappropriate for the individual’s age and language skills, persist over time, and are characterized by frequent and marked occurrences of at least 1 of the following:

  1. Sound and syllable repetitions
  2. Sound prolongations of consonants as well as vowels
  3. Broken words (e.g. - pauses within a word)
  4. Audible or silent blocking (filled or unfilled pauses in speech)
  5. Circumlocutions (word substitutions to avoid problematic words)
  6. Words produced with an excess of physical tension
  7. Monosyllabic whole-word repetitions (e.g. - “I-I-I am fine”)
Criterion B

The disturbance causes anxiety about speaking or limitations ineffective communication, social participation, or academic or occupational performance, individually or in any combination.

Criterion C

The onset of symptoms is in the early developmental period. (Adults are diagnosed as adult-onset fluency disorder).

Criterion D

The disturbance is not attributable to a speech-motor or sensory deficit, disfluency associated with neurological insult (e.g. - stroke, tumour, trauma), or another medical condition and is not better explained by another mental disorder.

Other Diagnostic Features

Interestingly, the dysfluencies from stuttering are usually absent during oral reading, singing, or talking to inanimate objects or to pets. The deficits are most severe when is a special pressure to communicate or stressful environment.
  • Sensory deficits
    • Dysfluencies of speech can be caused by hearing impairment, sensory deficit, or a speech-motor deficit. Only when the speech dysfluencies are in excess of what is expected, should a diagnosis of childhood-onset fluency disorder be made.
  • Normal speech dysfluencies
    • Normal dysfluencies occur frequently in young children. This includes whole-word or phrase repetitions (e.g. - “I want, I want that toy!”), incomplete phrases, interjections, unfilled pauses, and parenthetical remarks. If these difficulties continue to increase in frequency or complexity with age, then childhood-onset fluency disorder is more likely.
  • Medication side effects
    • Stuttering can occur as a side effect from medications. This should be correlated with a temporal history of exposure to the medication.
  • Adult-onset dysfluencies
    • If the dysfluency begins during or after adolescence, it is an diagnosed as adult-onset dysfluency instead. Adult-onset dysfluencies are usually due to a neurological insult, medical conditions, or mental disorders. It is not considered a DSM-5 diagnosis.
    • The vocal tics and repetitive vocalizations from Tourette's disorder should be distinguished from the repetitive sounds of childhood-onset fluency disorder by their nature and timing.

Speech therapy can be used to encourage the individual to speak more slowly and effectively. Cognitive behavioural therapy can also be used to identify thoughts processes that worsen stuttering, and to identify coping strategies related to stress from stuttering. Electronic delayed auditory feedback tools can also be used to help individuals to slow down their speech. Around 65%-85% of children with stuttering recover.