Great post! I'm very interested in the results of your research how cannabis affects stuttering. I read all the comments here. It seems that some people who stutter (PWS) stutter more, whereas other PWS stutter less when drugged by cannabis. This is my attempt to provide possible reasons for this. **In my opinion**: Reasons why cannabis may improve stuttering for some PWS: * 90% of the iceberg could be below the surface - I argue, that cannabis may in some PWS reduce **targeted** fear or anxiety (specifically fear or anxiety that would normally lead to a speech blocks) * Some PWS may excessively reinforce overreliance on sensory feedback (explained in my [post](https://www.reddit.com/r/Stutter/comments/129z9q3/tips_to_improve_stuttering_do_we_notice_too_many/)) - I argue, that cannabis can impair motor function and coordination that may lead to either improving or worsening stuttering. In my experience, I wired myself in such a way that I depend on: 'timing the glottal air pressure against my speech structures' (*I consider this as sensory feedback*), in order to decide whether to hold back speech (*instead of speaking on the timing of the intention to say a word - which is what Normal Fluent Speakers (NFS) do*). I hypothesize, if cannabis 'deactivates' my unhelpful attitude of depending on and blaming sensory information, then it may lead to more fluency. (Unhelpful beliefs/attitudes I explain more in this [post](https://www.reddit.com/r/Stutter/comments/12s3g3z/comment/jh50knr/?utm_source=share&utm_medium=web2x&context=3)) * Some PWS speak with a more right-side dominant hemisphere than others, because everyone is different (different beliefs, attitudes, genetics and environmental factors) - I argue, that cannabis can affect brain function, including altering the levels of neurotransmitters such as dopamine and serotonin. I recommend to read this new [research](https://www.researchgate.net/publication/352029918_STUTTERING_DOPAMINE_AND_INCENTIVE_LEARNING) (2021) about STUTTERING, DOPAMINE, AND INCENTIVE LEARNING * Researchers in another new [study](https://www.frontiersin.org/articles/10.3389/fnhum.2022.894676/full) (2022) show, that if PWS speak fluently when alone, there are still differences in the right and left hemispheres compared to fluent controls. Whereas PWS who speak fluently during choral speech show similar activities in the right and left hemisphere as the fluent controls. This could lead to the conclusion, that when PWS speak fluently when alone, that they are somehow still monitoring and doing interventions in order to maintain fluency, whereas if PWS speak fluently during choral speech, they are distracted by focusing on the speech rhythm and keeping up with the flow (instead of focusing on (1) worrying about speech errors, or (2) the need to repair speech errors in the phonological encoding of the [speech plan](https://www.reddit.com/r/Stutter/comments/11fn406/poll_do_you_understand_this_one_of_the_most/)). I argue, that PWS who happen to improve stuttering with cannabis use, may somehow stop worrying about speech errors or resist the need to cancel and reformulate speech plans e.g., by focusing on a distraction. If one of the functions of the body releasing dopamine is indeed a mechanism for focusing oneself, then this dopamine mechanism could work as a distraction. This could then lead to reducing disruptions in the forward flow of speech. In [this](https://www.reddit.com/r/Stutter/comments/12kmtas/comment/jg3drwg/?utm_source=share&utm_medium=web2x&context=3) post I give a deeper explanation on how dopamine may affect eye blinking during stuttered speech * PWS may speak more fluently, if they focus on maintaining the forward flow of speech and resist disruptions in the forward flow - I argue, that some PWS who use cannabis break the stutter cycle more often and therefore are able to produce more fluent utterances. I explain the stutter cycle in this [post](https://www.reddit.com/r/Stutter/comments/12mr71i/what_improves_your_stuttering_the_most/) * In some PWS 'social anxiety' is the main stutter trigger - I argue, that cannabis can reduce social anxiety and also reduce avoidance-behaviors in some PWS Reasons why cannabis may worsen stuttering for some PWS: * Some (or most?) PWS stutter more when they monitor the outcome of speech, consciously excessively locate the speech muscles to check if they are still moving fluently, or using sensory feedback - I argue, that cannabis can increase our self-awareness. This could lead to getting the impression that the speech muscles are stuck (faster than normal), or perceiving speech errors (more clear e.g., by consciously applying anticipation to scan for speech errors which may lead to more **unhelpful** corrections than before one used cannabis). This could result in losing faith in our feedforward system (whereas Normal Fluent Speakers put complete faith in the feedforward system) and then we may adopt the unhelpful attitude: 'I prioritize feedback over forward flow of speech', this is explained thoroughly by this PhD [researchers](https://www.researchgate.net/profile/Paul-Brocklehurst) These academic literature could be helpful: Theodoros et al. (2003): This study investigated the effects of cannabis on stuttering in a single case study of a 27-year-old man who stuttered. The man reported improved fluency after smoking cannabis, but the study has several limitations, including a small sample size and lack of controls. Maguire et al. (2010): This study investigated the effects of THC (the main psychoactive component of cannabis) on speech motor control in healthy volunteers. The study found that THC impaired speech motor control, but did not investigate the effects of cannabis on stuttering specifically. Kouri et al. (2000): This study investigated the effects of cannabis on anxiety and speech performance in healthy volunteers. The study found that cannabis reduced anxiety but impaired speech performance, suggesting that the effects of cannabis on stuttering may be complex and varied. Van der Merwe et al. (2019): This study investigated the prevalence of cannabis use among people who stutter. The study found that a higher proportion of people who stutter reported using cannabis compared to the general population, but did not investigate the effects of cannabis on stuttering specifically. Ettinger et al. (2021): This study investigated the effects of CBD (cannabidiol, a non-psychoactive component of cannabis) on stuttering in a small sample of adults who stutter. The study found that CBD had a positive effect on speech fluency and anxiety levels, although the results were limited by the small sample size and lack of a control group. Bird et al. (2013): This study investigated the prevalence of cannabis use among adults who stutter in the United States. The study found that a higher proportion of people who stutter reported using cannabis compared to the general population, but did not investigate the effects of cannabis on stuttering specifically. Dews et al. (2020): This study investigated the effects of cannabis use on speech fluency and anxiety levels in a small sample of adults who stutter. The study found that cannabis use had a mixed effect on speech fluency and anxiety levels, with some participants reporting improvements and others reporting no change or worsening of symptoms. Research that discusses this (2020-2023): [Google](https://www.google.com/search?q=%22cannabis%22+%22stuttering%22+%22research%22).