Cannabis and Auditory Effects: Tinnitus and Hearing Loss
Direct Answer
Heavy cannabis use does not appear to directly cause hearing loss, but emerging evidence suggests it may worsen or promote tinnitus development, particularly in individuals with pre-existing hearing damage. 1
Evidence on Tinnitus
Cannabinoids May Worsen Tinnitus
The most rigorous experimental evidence comes from animal studies showing that cannabinoid CB1 receptor agonists (THC and CBD combination) significantly increased the number of animals developing tinnitus following acoustic trauma, rather than providing relief. 1 This contradicts the theoretical rationale that cannabinoids' anti-epileptic properties might reduce neuronal hyperactivity underlying tinnitus. 1, 2
Clinical Observations in Humans
A scoping review of cannabis-related side effects in otolaryngology identified unintended tinnitus as an associated adverse effect of cannabis use. 3 However, this review noted substantial heterogeneity and moderate to critical risk of bias across studies. 3
Patient Perspectives vs. Evidence
Interestingly, there is a disconnect between patient experience and experimental data:
- 80% of tinnitus patients actively using cannabis reported subjective improvement in tinnitus-related symptoms (anxiety, sleep disturbances, dizziness), though not necessarily the tinnitus itself. 4
- 96% of tinnitus patients surveyed would consider cannabis as treatment, primarily for associated symptoms rather than the auditory perception itself. 4
This suggests cannabis may help with the psychological distress and secondary symptoms of tinnitus without addressing—and potentially worsening—the underlying auditory phenomenon. 4
Evidence on Hearing Loss
Direct Auditory Effects
Cannabis use has been associated with hearing loss in otolaryngology literature, though the quality of evidence is limited. 3 The scoping review found that approximately 54% of studies showed either increased side effects or no symptom change following cannabis use. 3
Mechanisms and Confounders
The relationship between cannabis and hearing loss remains unclear due to:
- Frequent concomitant tobacco use, which confounds respiratory and potentially auditory outcomes. 5
- Cannabinoid receptors are present in the auditory system at both peripheral and central levels, suggesting biological plausibility for auditory effects. 6, 2
- Cannabis may provide some protection against auditory damage through neuroimmunological mechanisms, though this protective effect is not well-established in humans. 6
Neurological Context
Heavy cannabis use causes documented neurological effects that may indirectly impact auditory processing:
- Altered gray matter volume and cortical thickness in key brain regions, particularly with adolescent use. 5
- Disrupted connectivity in the prefrontal cortex, affecting sensory processing and decision-making. 5
- Changes in glutamate and dopamine signaling, which could theoretically affect auditory perception circuits. 5
Clinical Implications and Caveats
Key Warnings
Patients with pre-existing hearing damage or tinnitus should be counseled that cannabis may worsen their auditory symptoms rather than provide relief, despite widespread patient belief to the contrary. 1, 3
Common Pitfalls to Avoid
- Do not recommend cannabis for tinnitus treatment based on its anti-epileptic properties or patient anecdotal reports—experimental evidence suggests harm. 1
- Distinguish between tinnitus perception and tinnitus-related distress—cannabis may help anxiety and sleep but worsen the auditory symptom itself. 4
- Consider that increasing THC potency (average concentration nearly doubled from 9% in 2008 to 17% in 2017, with concentrates reaching 70%) may intensify all adverse effects. 5
Cardiovascular and Other Systemic Effects
Heavy cannabis use carries additional risks relevant to overall health:
- Adverse cardiovascular events including arrhythmias, myocardial ischemia, and orthostatic hypotension. 7, 5
- Respiratory effects including chronic bronchitis and COPD with smoked cannabis. 5
- Cannabis use disorder develops in approximately 10% of chronic adult users, with withdrawal symptoms including irritability, sleep disturbances, and abdominal pain. 5, 8
Quality of Evidence Assessment
The evidence base is limited and heterogeneous:
- Animal studies provide the strongest mechanistic evidence showing cannabinoids promote tinnitus development. 1
- Human observational data is of low to moderate quality with substantial confounding. 3
- No high-quality randomized controlled trials exist examining cannabis effects on hearing or tinnitus in humans. 3
Given the precautionary principle in clinical medicine and the experimental evidence of harm, cannabis should not be recommended for auditory symptoms. 1, 3