4 Classification and assessment in psychiatry4.1 Descriptive psychopathology
4.1.7 Language and speech disorders
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Written by Resident Doctor Committee · Published
New in the 2027 syllabus
The College added this topic for exams from January 2027.
Language, speech and thought are different things
Language is the system of symbols we use to share meaning, through speech, writing or signing.
Speech is spoken output. It needs planning, then coordinated movement of the breathing muscles, the larynx (voice box) and the articulators, such as the lips and tongue.
Thought disorder is a problem with how thinking is organised, which we infer from how a person communicates. Unusual speech alone does not show a neurological language disorder.
Disorder | Main problem | Bedside clue |
|---|---|---|
Aphasia | Acquired impairment of language | Naming, comprehension, repetition, reading or writing are affected |
Dysarthria | Carrying out speech movements | Slurred or distorted articulation, with language otherwise intact |
Apraxia of speech | Planning speech movements | Effortful speech with inconsistent sound errors |
Dysphonia | Producing the voice | Hoarse, weak or altered voice |
Mutism | No speech | Assess language, consciousness, motor function and the psychiatric context |
Assessing motor speech and voice
Examine movement of the face, tongue and palate, and listen to voice quality and articulation. The aim is to tell a problem carrying out speech apart from a problem planning speech sounds.
Ask the person to repeat words of increasing length. In apraxia of speech this can bring out inconsistent errors, groping and abnormal stress. No single feature makes the diagnosis.
These problems can coexist. After brain injury, aphasia, dysarthria and apraxia can occur together, so one speech feature does not tell you that understanding is intact.
Mutism can occur with catatonia, severe mood disorder, neurological disease or selective mutism. Work out the context and look for associated signs before deciding on a cause.
Communication and urgency
Other ways of responding, such as writing, pointing or signing, help show whether the problem lies in spoken output or in language itself, if vision, movement and literacy allow.
Assess in the person's strongest language and take their previous communication abilities into account. Use interpreters and allow for hearing loss.
Sudden onset of a new speech or language problem needs urgent stroke assessment, even when only speech seems affected.
Support communication with short sentences, time to respond, gestures, and speech and language therapy. Difficulty expressing oneself does not prove a lack of capacity.
Psychiatric terms that are not aphasia
Pressure of speech is about the rate and amount of speech. Alogia is reduced speech output or content. Neither means the same as aphasia.
Echolalia is repeating another person's words; palilalia is repeating your own. Describe what you observe before deciding on a cause.