12 More Medical Conditions Cannabis Treats — Part 2

In Part 1, we covered 19 medical conditions cannabis treats — from treatment-resistant epilepsy and MS spasticity to Alzheimer's and fibromyalgia — alongside the clinical reality of what alcohol actually treats (antidote, antiseptic, nerve ablation). Here we continue with 12 more conditions, each grounded in the same biological infrastructure: the endocannabinoid system (ECS).

As a reminder, the ECS consists of two primary receptors — CB1 (concentrated in the brain and central nervous system, governing pain, mood, and movement) and CB2 (expressed on immune cells, dictating inflammation). This system is distributed throughout the entire body, which explains why cannabinoids can influence everything from brain chemistry to skin cells to gut motility. [Basu & Dittel (2020, Frontiers in Immunology)]

20. Migraine & Cluster Headaches

The Science: Migraine is heavily linked to Clinical Endocannabinoid Deficiency (CECD). Research shows that chronic migraineurs have significantly lower levels of anandamide (AEA) — our primary endogenous cannabinoid — in their cerebrospinal fluid. AEA normally acts as a tonic brake on pain in the periaqueductal grey matter, a key "migraine generator" region of the brainstem. [Association of Cannabinoid Specialists]

How Cannabinoids Help: Exogenous THC and CBD step in to replace this missing endocannabinoid tone. THC activates CB1 receptors on presynaptic nerve terminals in the trigeminovascular system, directly inhibiting the release of Calcitonin Gene-Related Peptide (CGRP) — the signalling peptide responsible for dilating cranial blood vessels and triggering intense neurogenic pain. Simultaneously, cannabinoids modulate serotonin (5-HT1A and 5-HT2A) receptors to dampen the sensory hyper-reactivity causing photophobia and nausea. [Akerman et al. (2009, Pain)]

The Evidence: A 2019 systematic review in Cannabis and Cannabinoid Research found that medical cannabis reduced migraine frequency by an average of 50% across multiple studies. Patients reported significant reductions in acute pain intensity and reduced reliance on triptans and NSAIDs. [Rhyne et al. (2019)]

21. Autism Spectrum Disorder (ASD)

The Science: ASD is characterised by a disruption in the brain's Excitatory/Inhibitory (E/I) balance — an overabundance of excitatory glutamate signalling relative to calming GABA signalling. Studies have also identified lower circulating levels of endocannabinoids in children on the spectrum, suggesting a deficiency in the body's natural regulatory system. [Zamberletti et al. (2017)]

How Cannabinoids Help: CBD acts as a positive allosteric modulator of GABA-A receptors — it changes the shape of the receptor to make it more receptive to the brain's natural calming chemicals. By restoring the E/I balance and reducing hippocampal hyper-excitability, CBD-dominant formulations significantly decrease severe irritability, self-injurious behaviours, and sensory overload without causing sedation. [Zamberletti et al. (2017)]

The Evidence: The largest study to date, published in Frontiers in Pharmacology, followed 188 children with ASD treated with CBD-rich cannabis. After six months, 74.5% of patients showed significant improvement in behavioural episodes, 71% in sleep quality, and 67% in self-injury. [Bar-Lev Schleider et al. (2019)]

22. Traumatic Brain Injury (TBI) & Concussions

The Science: The initial impact of a TBI triggers a destructive secondary injury cascade: massive glutamate excitotoxicity (damaged cells dump toxic glutamate, frying neighbouring neurons), an explosion of free radicals, and a breakdown of the blood-brain barrier. This cascade often causes more damage than the initial impact. [Shover et al. (2019)]

How Cannabinoids Help: The body naturally floods the brain with endocannabinoids immediately after an injury as a built-in defence mechanism. Supplying plant cannabinoids reinforces this process. CBD blocks glutamate toxicity by stimulating adenosine A2A signalling, shutting down excess glutamate release. Meanwhile, activating CB2 receptors on microglial cells switches them from a pro-inflammatory destructive state to an anti-inflammatory repair state, minimising long-term structural damage. [Shover et al. (2019)]

The Evidence: Preclinical models consistently demonstrate that cannabinoid administration within hours of brain injury significantly reduces lesion size, cerebral oedema, and functional deficits. A 2020 review in Neuropharmacology concluded that cannabinoids represent a "promising therapeutic frontier" for TBI due to their multimodal neuroprotective effects. [Covi et al. (2020, Neuropharmacology)]

23. Interstitial Cystitis (Bladder Pain Syndrome)

The Science: Interstitial cystitis is a chronic, painful inflammation of the bladder wall. The protective urothelium (bladder lining) thins, allowing urine to irritate deeper tissues. Mast cells infiltrate the area and release histamine, causing agonising pelvic pain and severe bladder hyper-reactivity (frequency and urgency). [MDPI — Cannabinoids and Bladder]

How Cannabinoids Help: The urinary bladder expresses a high density of CB1 and CB2 receptors. CBD helps repair the damaged urothelial structure and improves the integrity of the blood-urine barrier. Cannabinoids act on CB2 receptors to stop mast cells from degranulating (releasing inflammatory chemicals), while simultaneously targeting mucosal afferent nerves to suppress bladder spasms and overactivity. [MDPI — Cannabinoids and Bladder]

24. Opioid Use Disorder & Addiction Harm Reduction

The Science: Chronic opioid use hijacks the brain's mesolimbic dopamine pathway and hypersensitises the amygdala. When opioids are removed, the amygdala fires intensely, creating severe cue-induced craving, profound anxiety, and physical withdrawal that frequently leads to relapse.

How Cannabinoids Help: CBD acts as an agonist at the serotonin 5-HT1A receptor, directly dampening the stress and anxiety driving the urge to consume. It also alters the neuroplasticity of reward circuitry, weakening the consolidated memory links between environmental cues (seeing a syringe or pill bottle) and the compulsive urge to use. Clinically, this serves as an "exit ramp" — an adjunctive therapy to reduce opioid reliance and prevent overdose. [Hurd et al. (2020, American Journal of Psychiatry)]

The Evidence: A 2020 randomised controlled trial published in the American Journal of Psychiatry found that CBD significantly reduced cue-induced craving and anxiety in individuals with heroin use disorder, providing the first robust clinical evidence for CBD as a treatment for opioid use disorder. [Hurd et al. (2020)]

25. Diabetic Peripheral Neuropathy (DPN)

The Science: Prolonged high blood sugar causes microvascular damage, starving peripheral nerves of oxygen. This leads to ischaemic nerve damage, oxidative stress, and the classic "burning, stabbing, or pins-and-needles" sensations in the extremities. DPN affects up to 50% of long-term diabetics.

How Cannabinoids Help: Cannabinoids target CB1 receptors in the dorsal horn of the spinal cord — the primary gatekeeper for pain signals travelling from the limbs to the brain. By activating these receptors, cannabinoids shut down ascending nociceptive (pain) pathways. In the periphery, CBD's antioxidant properties neutralise the reactive oxygen species (ROS) destroying nerve endings, while reducing macrophage infiltration to slow the progression of nerve damage itself.

The Evidence: A systematic review of cannabinoids for diabetic neuropathy concluded that cannabis-based medicines provided statistically significant pain reduction compared to placebo, with a number needed to treat (NNT) comparable to established first-line neuropathic pain medications like gabapentin. [Wallace et al. (2017, Diabetes, Obesity and Metabolism)]

26. Systemic Lupus Erythematosus (SLE)

The Science: Lupus is a systemic autoimmune condition where B-lymphocytes become hyperactive and produce massive amounts of autoantibodies — antibodies that mistake the body's own tissues for foreign invaders. This results in widespread immune-complex deposition, causing severe joint, skin, and kidney inflammation.

How Cannabinoids Help: Immune cells are packed with CB2 receptors. Activation of the CB2 pathway suppresses T-cell proliferation and down-regulates the production of aggressive pro-inflammatory cytokines like TNF-alpha and IL-6. This halts the signalling loop that tells B-cells to keep churning out autoantibodies, offering a non-steroid pathway to calm systemic flares. [Pandey et al. (2012, Clinical Immunology)]

27. Restless Legs Syndrome (RLS)

The Science: RLS is a sensorimotor disorder tied to central dopamine imbalances in the basal ganglia — the brain's movement control centre. When dopamine signalling drops (typically in the evening), it triggers involuntary movement urges and uncomfortable crawling sensations deep within the legs. [My Patient Advice — RLS & Cannabis]

How Cannabinoids Help: Cannabinoids do not directly replace dopamine, but they act as a regulatory mesh network. The endocannabinoid system is heavily intertwined with dopaminergic pathways in the striatum. THC helps smooth the erratic fluctuations of dopamine release, preventing the neurological misfires that cause legs to twitch. Simultaneously, it dampens the abnormal sensory signalling in the spinal cord, eliminating the "crawling" sensation so patients can maintain deep, uninterrupted sleep. [My Patient Advice — RLS & Cannabis]

28. Phantom Limb Pain

The Science: Following an amputation, the sudden loss of sensory input causes the spinal cord and the brain's somatosensory cortex to undergo maladaptive plastic reorganisation. Nerves at the stump become hyper-excitable, creating "ectopic pacemakers" that send constant phantom pain signals to a brain map that still thinks the limb is there.

How Cannabinoids Help: This is a severe form of central sensitisation. THC acts as a powerful CB1 receptor agonist to suppress these ectopic nerve discharges at the spinal level. By blocking retrograde signalling at the synaptic junction, cannabinoids prevent the amplification of these ghost signals, essentially decoupling the brain's sensory map from the chronic, illusory pain impulses. [Wilsey et al. (2016, Pain)]

29. Graft-Versus-Host Disease (GVHD)

The Science: Occurring after bone marrow or stem cell transplant, GVHD happens when the donor's immune cells recognise the patient's body as foreign and launch a massive, life-threatening immune assault against the patient's skin, liver, and gut.

How Cannabinoids Help: CBD has demonstrated remarkable efficacy due to its unique immunosuppressive properties. CBD actively induces apoptosis (programmed cell death) in the hyperactive, attacking donor T-lymphocytes. It also up-regulates myeloid-derived suppressor cells, which act as immune peacekeepers, helping the new immune system develop tolerance toward the host's organs. [Yeshurun et al. (2015, Blood)]

30. Anorexia Nervosa

The Science: Unlike AIDS-related wasting (purely physical cachexia), Anorexia Nervosa is a complex psychological eating disorder involving disturbed reward processing and interoception — the ability to accurately perceive internal bodily states like hunger. Brain imaging shows altered CB1 receptor binding and density in the insular cortex of these patients.

How Cannabinoids Help: Low, carefully titrated doses of THC target the dysregulated CB1 receptors in the insula and hypothalamus. This works on two fronts: it normalises ghrelin (the "hunger hormone") signalling to stimulate chemical appetite, and it restores the hedonic reward of eating. By making food taste and feel rewarding again in the brain's circuitry, it helps break the severe cognitive resistance to calorie consumption. [Monteleone et al. (2018, Translational Psychiatry)]

31. Ankylosing Spondylitis (AS)

The Science: AS is a chronic, destructive inflammatory arthritis that primarily attacks the spine and sacroiliac joints. Driven by the IL-23/IL-17 genetic pathway, it causes chronic mechanical back pain, severe morning stiffness, and can eventually lead to calcification and fusion of spinal vertebrae.

How Cannabinoids Help: The severe pain in AS is a mix of inflammatory damage and central sensitisation caused by constant spinal remodelling. Cannabinoids deliver a dual-action approach: they bind to CB2 receptors on spinal microglia to inhibit the synthesis of specific arthritogenic cytokines (IL-17 and TNF-alpha) driving joint destruction, while simultaneously targeting CB1 receptors in the central nervous system to turn down the volume on the unremitting structural bone pain that traditional NSAIDs fail to control. [Katz-Talmor et al. (2020, Rheumatology)]

The Core Comparison Revisited

Across all 31 conditions in Parts 1 and 2, a clear pattern emerges. Cannabis targets a precise, complex signalling network (the ECS) designed to maintain internal balance. Alcohol acts as a non-specific central nervous system depressant and a physical solvent that disrupts cellular membranes globally.

The toxicological profiles are equally divergent. Cannabis possesses zero risk of fatal respiratory overdose because the brainstem lacks CB1 receptors. Alcohol has high systemic toxicity requiring strict medical monitoring to avoid respiratory depression and liver failure. Cannabis can be taken daily for years without causing organ failure; chronic alcohol consumption directly causes cirrhosis, pancreatitis, cardiomyopathy, and seven forms of cancer. [WHO — Alcohol and Cancer]

This is not an opinion. It is a summary of the peer-reviewed biomedical literature. The ECS is a real biological system. Cannabinoids are real signalling molecules that interact with it. Alcohol is a real cellular toxin that does not. The therapeutic implications of this fundamental biochemical difference are vast — and they are only beginning to be explored.

Read Part 1: 19 Conditions + What Alcohol Actually Treats | The Verdict: Alcohol vs Cannabis by Every Metric