Cannabis for Anxiety Disorders and PTSD: Opportunities and Risks

Cannabis and anxiety are in a paradoxical relationship: on one hand, "paranoia" is one of the most frequently reported adverse effects of cannabis. On the other hand, anxiety relief is one of the most common reasons people use cannabis medicinally. How can this contradiction be explained?

## The Paradox: Cannabis as Anxiety Trigger and Anxiety Reliever

The resolution of the paradox lies in dose-dependence and in the differences between cannabinoids:

THC and anxiety – dose-dependent: Low-dose THC can have anxiolytic (anxiety-reducing) effects. High-dose THC can trigger anxiety and paranoia, especially in inexperienced users or unfamiliar environments. This biphasic effect is well documented. The "tipping point" for most people lies somewhere between 7.5 and 12.5 mg THC.

CBD and anxiety: CBD shows a significantly more favourable profile. Several clinical studies have shown that CBD has anxiety-reducing effects – without the risk of itself causing anxiety. A widely cited study (Bergamaschi et al., 2011) showed that CBD (600 mg oral) significantly reduced anxiety in people with social phobia during a simulated public speech.

## Post-Traumatic Stress Disorder (PTSD)

PTSD is perhaps the application area for which the cannabis data is most interesting. THC suppresses REM sleep – dream sleep. For PTSD patients suffering from distressing flashbacks and nightmares, this can be helpful in the short term. Several case series and retrospective studies report that cannabis significantly reduces the frequency and intensity of nightmares in PTSD.

Canadian war veterans with PTSD have been the driving force behind medical cannabis prescriptions for years. The practice is widespread, even if the evidence is still incomplete.

## Generalised Anxiety Disorder and Social Phobia

For generalised anxiety disorder (GAD), robust clinical evidence for cannabis is lacking. Problematically, regular cannabis use in people with anxiety disorders can lead to a vicious cycle: cannabis reduces anxiety short-term (negative reinforcement) but increases baseline anxiety long-term through tolerance development and withdrawal phenomena.

## What BlattWerk Recommends

Anyone wanting to use cannabis for anxiety disorders or PTSD should: inform and involve a doctor; start with low-dose CBD-emphasised cannabis or pure CBD; be especially cautious with THC-rich products; not use cannabis as a substitute for psychotherapeutic treatment; and monitor their own use – is anxiety getting better or worse in the long term?