Do Small Doses Of Cannabis Improve Schizophrenia Symptoms?

Cannabis for schizophrenia is a controversial topic. But, why does this study suggest that low doses may improve general functioning?

Oct 10, 2016

There’s a lot of controversy in the cannabis world surrounding THC and schizophrenia. Though high doses of cannabis may mean bad news for those with the condition, new clinical trials and research show that the herb may be beneficial when used correctly. But, do small doses of cannabis improve schizophrenia symptoms? 

Study on cannabis dosage and schizophrenia

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For decades, the cannabis plant’s mind-altering abilities have been associated with madness, psychosis, and an increase in schizophrenia. Yet, when it comes down to numbers, these associations just don’t stack up.

While rates of cannabis use and potency have gone up dramatically, rates of schizophrenia remain the same. All in all, about 1.1% of the world population has the condition.

But, if you already have schizophrenia, does cannabis make it worse? A 2015 paper set out to address whether or not cannabis actually worsened psychotic symptoms in patients. A British research team led by Christine Barrowclough, Ph.D. recruited 110 patients diagnosed with schizophrenia.

All of the patients in the study had also been diagnosed by a psychiatrist as having co-occurring cannabis dependence. The British team wanted to find out whether changing the dose of cannabis changed their symptoms or triggered a relapse in psychosis.

The team tested the patients every 4.5, 9, and 18 months. On average, the patients consumed about 1.3 grams of cannabis about 4 to 5 days per week.

The results

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Barrowclough’s team found that cannabis use did not worsen the primary symptoms of schizophrenia. In general, symptoms of the condition are broken up into two categories: positive and negative. Positive symptoms include hallucinations, paranoia, delusions. Negative symptoms include a lack of affect, pleasure, and social withdrawal.

Yet, high doses of cannabis may worsen symptoms of depression and anxiety. The study concluded,

There was no evidence of a specific association between cannabis use and positive symptoms, or negative symptoms, relapse or hospital admissions. However, a greater dose of cannabis was associated with subsequent higher depression and anxiety. – Barrowclough

In higher doses, depression and anxiety increased in cannabis-using patients. Yet, these symptoms were avoided in those taking lower doses of the herb. All in all, low doses of cannabis use were associated with general improvements in the condition. Barrowclough writes,

Cannabis use was associated with an improvement in general functioning, a finding that was also evident in our earlier study with a sample of patients with longer illness history.

Is THC safe for those with schizophrenia?

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Unfortunately, the answer to this question remains a mystery. In general, it is not recommended for those with psychotic disorders like schizophrenia to use psychoactive substances. Or anything that places unnecessary stress on the body.

Some studies have found that heavy adolescent cannabis use is associated with earlier onset of primordial symptoms of schizophrenia. This statistic is for those who are genetically predisposed, which is about 1 in 3,000 adolescent cannabis users.

Others show that the genetic predisposition to schizophrenia also might make them more predisposed to cannabis use. Though, this same predisposition might also make patients more likely to consume cannabis in higher quantities, which may make them worse off.

While many patents may fall under the umbrella of “schizophrenia”, every person is unique. What might be helpful and appropriate for one patient’s body chemistry may wreck havoc in someone else.

Which is exactly what a 2010 study found, when it was discovered that a certain subset of schizophrenia patients are sensitive to cannabis while others were not.

Genetic and environmental factors strongly shape the condition, though symptoms are typically brought about by a precipitating event that causes intense acute stress. This precipitating event can be a trauma or something environmental or lifestyle-related that pushes the body over the brink, so to speak.

It’s well known that THC can increase anxiety and paranoia in high doses. If you struggle with either of those symptoms, the herb can certainly make things worse. If the conditions are right, it’s possible that for some cannabis can be a precipitating event.

But, as one Harvard study suggests, there is no evidence that the herb causes the disorder. And as Barrowclough’s work hints, the herb, when intake is reduced in adults, may not automatically make things worse. Based on the evidence so far, it seems like researchers and patients have a lot to learn about cannabis and schizophrenia.

Trials of cannabis therapy for schizophrenia

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Yet, not all cannabinoids have an anxious or paranoid effect. In fact, one pharmaceutical company is already working on cannabis-based drugs for schizophrenia.

In a phase 2 placebo-controlled clinical trial, nonpsychoactive cannabidiol (CBD) outperformed controls in treatment-resistant schizophrenia. 88 patients were tested, though all of them remained on their typical antipsychotic medications. Overall, CBD improved symptoms without causing any adverse events.

GW Pharmaceuticals CEO Justin Grover is hopeful about cannabinoid medicines for schizophrenia.

These findings further reinforce the potential role of cannabinoids in the field of neuropsychiatric disease. We believe that the signals of efficacy demonstrated in this trial, together with a notably reassuring safety profile, provide GW with the prospect of new and distinct cannabinoid neuropsychiatric product pipeline opportunity. – Grover

The link between cannabis and schizophrenia is far more complicated than commonly thought. Being predisposed to schizophrenia might make you more likely to consume cannabis. Consuming a lot of cannabis may make things worse. Using cannabis when you’re young may increase risks in those predisposed to the condition.

Yet, low doses of the herb in adults have been associated with overall improvement in general functioning. There is no evidence that the herb itself causes schizophrenia.

Further, extractions from nonpsychoactive cannabis have had positive results in clinical trials.

Oct 10, 2016