Jerome Sarris Ph.D., MHSc

Nature and Natural Medicines

Can Medicinal Cannabis Benefit Your Mental Health?

Research is now exploring the potential beneficial effects of cannabis.

Posted Nov 04, 2019

Global acceptance of cannabis has increased in recent years, due in part to a shifting regulatory landscape which more and more is favouring decriminalisation. So people may well ask Is cannabis right for me? Could it be beneficial for my mental health? Or could it make it worse?

The general effects of the cannabis plant are well-known: the positive ranging from having relaxant/sedative, mood-elevating and even euphoric, and appetite-inducing actions, and the negative being that it can cause dizziness, disorientation, paranoia and anxiety, drowsiness or fatigue, dry mouth, nausea and gastrointestinal upsets, as well as impairing mental function and motor skills. It should, however, be firstly realised that the plant contains a complex range of natural chemicals and that the amounts of these (and the ratios) may cause different physical and mental effects. In fact, a major scientific aim currently is to increase our knowledge of this, so as to create ‘medicinal cannabis’ varieties to more precisely treat certain health conditions.

This is not surprising, as cannabis has been used for over 10 millennia as both a recreational product and medicine. Several medicinal applications have been studied increasingly over the past decade, with the National Academy of Sciences recently stating that cannabis and cannabinoids demonstrate either substantial or conclusive evidence for chemotherapy-induced nausea and vomiting, chronic pain, and spasticity in multiple sclerosis. They also note there is some, though limited, evidence for use in increasing appetite in HIV/AIDS patients.

There has also recently been increased research revealing that cannabis (or at least certain natural chemicals from the plant) can have a potentially beneficial effect for a range of psychiatric disorders.  Several clinical trials are also underway around the world, further researching cannabinoid therapies for conditions such as PTSD, ADHD, general anxiety, schizophrenia, or insomnia.

So where does the evidence currently sit? While research is fairly nascent, some research has shown that certain cannabis-derived chemicals (cannabinoids, and in particular ‘cannabidiol’ [known as CBD]) may be effective for reducing social anxiety; while mixed and mainly positive evidence has been revaled for add-on use with medication in schizophrenia. Case studies have also indicated that cannabis-based therapies may be beneficial for improving insomnia and PTSD, while one isolated study has shown some potential efficacy in ADHD. However, the overall evidence for these conditions is currently weak. Further, preliminary research indicates no benefit for depression from formulas containing higher amounts of the plant’s psychoactive compound delta-tetrahydrocannabinol [known as THC], while CBD was found to be not effective in mania (a presentation found in bipolar disorder). These inventions are usually given in an oral spray form or capsule, however, the research focusing on PTSD explored smoked inhalation of the dried cannabis flower.

There is well-regarded apprehension by many clinicians concerning the promotion of higher THC forms of cannabis due to the potential of causing psychotic symptoms. The heaviest users of cannabis are around four times as likely to develop schizophrenia than non-users. So too are adolescents and young adults, who have growing brains and are at an age where schizophrenia is more likely to manifest. Many modern recreational cannabis strains contain high amounts of THC that are often popular with consumers due to the “high” it may provide. However, with the high comes an increased risk of paranoia, anxiety, and psychosis (especially if genetically vulnerable). Due to this, higher THC dosages or forms of the plant should be avoided in people with or at risk of schizophrenia. However, it is feasible that standardised novel “medicinal cannabis” formulations with lower THC (or isolated compounds) may have negligible effects on psychosis risk. Heavy cannabis use (defined as daily use for at least one year), has also been associated with poorer attention and memory. Aside from these concerns, there’s the additional possibility of synthetic adulterants, chemical residues, heavy metals or other toxins being present due to a lack of quality assurance practices in less reputable producers. 

These considerations aside, there are however positive reasons why the plant may be of benefit to people with schizophrenia. In contrast to THC, the plant chemical CBD may provide a buffering effect to the potentially psychosis-inducing effects of THC. This may occur in part due to its ability to partially block the same brain chemical receptor which THC binds to. Some studies have found CBD is actually beneficial in improving the symptoms of schizophrenia. But one recent study showed no difference in the effects of CBD compared to a dummy pill on symptoms of schizophrenia. So while CBD looks promising, the jury is still out, and more research needs to assess its potential benefit.

So is cannabis right for you? Aside from legal considerations depending on where you live in the world, it comes down to various factors. It is firstly important to receive appropriate medical assessment, and if experiencing any mental illness to receive a proper diagnosis and medical/psychological care. Hopefully your medical professional will be open-minded enough to consider the use of medicinal cannabis (if in a legal jurisdiction), and certainly to consider recommending more benign compounds such as CBD. Clinical prescriptive consideration involves caution in the use of high-THC formulations (avoidance in youth, and in people with anxiety or psychotic disorders), gradual titration, regular assessment, and caution in cardiovascular and respiratory disorders, pregnancy and breast-feeding.

In various places, cannabis is now legal also for recreational use. The cannabis plant offers many potential medicinal benefits, and we are only at the beginning stage of understanding this. In the meantime, consider what is right for you, get good medical support and if cannabis is legal and appropriate for you, adopt the motto start low and go slow.


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