Cannabis-based medicinal products (CBMPs) are increasingly being used to treat post-traumatic stress disorder (PTSD), despite limited evidence of their efficacy. PTSD is often comorbid with major depression, and little is known about whether comorbid depression alters the effectiveness of CBMPs.

To document the prevalence of depression among individuals seeking CBMPs to treat PTSD and to examine whether the effectiveness of CBMPs varies by depression status.

Data were available for 238 people with PTSD seeking CBMP treatment (5.9% of the treatment-seeking sample) and 3-month follow-up data were available for 116 of these. Self-reported PTSD symptoms were assessed at treatment entry and at 3-month follow-up using the PTSD Checklist – Civilian Version (PCL-C). The probable presence of comorbid depression at treatment entry was assessed using the nine-item Patient Health Questionnaire (PHQ-9). Additional data included sociodemographic characteristics and self-reported quality of life.

In total, 77% met screening criteria for depression, which was associated with higher levels of PTSD symptomatology (mean 67.8 v. 48.4, F(1,236) = 118.5, P < 0.001) and poorer general health, quality of life and sleep. PTSD symptomatology reduced substantially 3 months after commencing treatment (mean 58.0 v. 47.0, F(1,112) = 14.5, P < 0.001), with a significant interaction (F(1,112) = 6.2, P < 0.05) indicating greater improvement in those with depression (mean difference 15.3) than in those without (mean difference 7).

Depression is common among individuals seeking CBMPs to treat PTSD and is associated with greater symptom severity and poorer quality of life. Effectiveness of CBMPs for treating PTSD does not appear to be impaired in people with comorbid depression.

Cannabis was used as a medicinal plant in Asia before the Christian era. Nowadays, after 40years of a “war on drugs” with an illegal status, there is a big interest on the use of cannabis in some medical conditions. With more and more users revealing having used this substance to cope with certain psychiatric manifestations, researchers have tried to explore this substance in the psychiatric field where the actual pharmacological treatments and psychotherapy remain ineffective in some cases.

To Explore the medical use of cannabis in psychiatric disorders.

A literature review was based on the PubMed interface and adapted for 2 databases: Science Direct and Google Scholar over the last 10 years.

Giving the interactions between cannabinoids and specific neurotransmitters, it has been suggested that cannabis may have medical effect on some psychiatric illnesses. In this direction, a significant overlap has been demonstrated between PTSD and cannabis use. CBD a non-psychotomimetic cannabinoid, seemed to show promising results as an enhancer of fear extinction and therapeutic consolidation of emotional memories. Military veterans are increasingly using it for reducing induced nightmares although this residual symptom remains difficult to treat. No benefit for improving depression was proved. One isolated study indicated a potential efficacy for cannabinoid combined with terpene in ADHD.

Studies exploring the possibility of using cannabis in the treatment of psychiatric illnesses are promising but it is premature to recommend this drug for the moment especially since it requires gradual titration, regular assessment and precaution in certain diseases.

No significant relationships.