Can include reductions in the amount of speech (poverty of speech) or speech that does not convey meaningful information (poverty of content of speech).
Alogia refers to speechlessness or a notable lack of spontaneity or responsiveness in conversation. Also, a deficiency in the amount or content of speech, it is a disturbance often seen in people with schizophrenia.
Alogia is referring to complete lack of speech, as in profound mental retardation or advanced dementia and in this case, it is synonymous with Aphasia. Alogia also means poverty of speech, as commonly occurs in schizophrenia.
Other /More definition:
Alogia refers to the deficit in both the quantity of speech and the quality of its expression. It is speechlessness or a notable lack of spontaneity or responsiveness in conversation.