46 Neurodevelopmental Disorders
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-I see him”).
B. The disturbance causes anxiety about speaking or limitations in effective communica-
tion, social participation, or academic or occupational performance, individually or in
any combination.
C. The onset of symptoms is in the early developmental period. ( Note:  Later-onset cases
are diagnosed as 307.0 [F98.5] adult-onset fluency disorder.)
D. The disturbance is not attributable to a s peech-motor or sensory deficit, dysfluency as-
sociated with neurological insult (e.g., stroke, tumor, trauma), or another medical con-
dition and is not better explained by another mental disorder.
Diagnostic Features
The essential feature of childho od-onset fluency disorder (stu ttering) is a disturbance in
the normal fluency and time patterning of spee ch that is inappropriate for the individual’s
age. This disturbance is characterized by freq uent repetitions or prolongations of sounds
or syllables and by other types of speech dysfluencies, including broken words (e.g.,
pauses within a word), audible or silent blocki ng (i.e., filled or unfilled pauses in speech),
circumlocutions (i.e., word su bstitutions to avoid proble matic words), words produced
with an excess of physical tension, and mono syllabic whole-word repetitions (e.g., “I-I-I-I
see him”). The disturbance in fluency interferes with academic or occupational achieve-