Language suppression (also known as aphasia) is medically recognized as the decreased ability to use and understand speech.   This creates the feeling of finding it difficult or even impossible to vocalize one's own thoughts and to process the speech of others. However, the ability to speak and to process the speech of others does necessarily become suppressed simultaneously. For example, a person may find themselves unable to formulate a coherent sentence while still being able to perfectly understand the speech of others.
- Expressive (also called Broca's aphasia): difficulty in conveying thoughts through speech or writing. The person knows what she/he wants to say, but cannot find the words he needs. For example, a person with Broca's aphasia may say, "Walk dog," meaning, "I will take the dog for a walk," or "book book two table," for "There are two books on the table."
- Receptive (Wernicke's aphasia): difficulty understanding spoken or written language. The individual hears the voice or sees the print but cannot make sense of the words. These people may speak in long, complete sentences that have no meaning, adding unnecessary words and even creating made-up words. For example, "You know that smoodle pinkered and that I want to get him round and take care of him like you want before." As a result, it is often difficult to follow what the person is trying to say and the speakers are often unaware of their spoken mistakes.
- Global : People lose almost all language function, both comprehension and expression. They cannot speak or understand speech, nor can they read or write. This results from severe and extensive damage to the language areas of the brain. They may be unable to say even a few words or may repeat the same words or phrases over and over again.
- Anomic (or amnesiac): the least severe form of aphasia; people have difficulty in using the correct names for particular objects, people, places, or events.
Language suppression is often accompanied by other coinciding effects such as analysis suppression and thought deceleration. It is most commonly induced under the influence of heavy dosages of antipsychotic compounds, such as quetiapine  , haloperidol  , and risperidone  . However, it can also occur in a less consistent form under the influence of extremely heavy dosages of hallucinogenic compounds such as psychedelics  , dissociatives   , and deliriants  . This is far more likely to occur when the person is inexperienced with that particular hallucinogen.
-  Aphasia - National Institute of Neurological Disorders and Stroke (NINDS) | https://www.ninds.nih.gov/disorders/All-Disorders/Aphasia-Information-Page
- Chien, C. F., Huang, P., & Hsieh, S. W. (2017). reversible global aphasia as a side effect of quetiapine: a case report and literature review. Neuropsychiatric disease and treatment, 13, 2257. | https://dx.doi.org/10.2147%2FNDT.S141273
- Iqbal, M. M., Aneja, A., Rahman, A., Megna, J., Freemont, W., Shiplo, M., ... & Lee, K. (2005). The potential risks of commonly prescribed antipsychotics: during pregnancy and lactation. Psychiatry (Edgmont), 2(8), 36. | https://www.ncbi.nlm.nih.gov/pubmed/21152171
- Sinha, P., Vandana, V. P., Lewis, N. V., Jayaram, M., & Enderby, P. (2015). Evaluating the effect of risperidone on speech: A cross-sectional study. Asian journal of psychiatry, 15, 51-55. | https://doi.org/10.1016/j.ajp.2015.05.005
- Kjellgren, A., & Jonsson, K. (2013). Methoxetamine (MXE)–a phenomenological study of experiences induced by a “legal high” from the Internet. Journal of Psychoactive Drugs, 45(3), 276-286. | https://dx.doi.org/10.1080%2F02791072.2013.803647
- Nguyen, H. T., & Juurlink, D. N. (2004). Recurrent ibuprofen-induced aseptic meningitis. Annals of Pharmacotherapy, 38(3), 408-410. | https://doi.org/10.1345%2Faph.1D329