The Silexan in the Treatment Of Posttraumatic stress disorder (STOP) Trial

The Silexan in the Treatment Of Posttraumatic stress disorder (STOP) Trial is investigating whether adding Silexan, a lavender oil medication, to treatment-as usual, improves PTSD symptoms in adults with PTSD. Participants will take Silexan, or placebo (dummy pills), daily in addition to their usual medications for 12 weeks. They will complete questionnaires every 2-4 weeks until week 16 (i.e. 4 weeks post-treatment).

Silexan is an oral medication containing lavender oil, an essential oil derived from the lavender plant. It is available over-the-counter in Australia and is already used to treat anxiety conditions, including Generalized Anxiety Disorder. There is evidence suggesting that it may also be effective in PTSD. Silexan has an excellent safety profile. The only known side effects are mild gastrointestinal symptoms such as burping and lavender breath odour and these are uncommon, occurring in approximately 6% of patients.

To be eligible for the STOP Trial, participants must:*

· Be aged 18 and over

· Have been diagnosed with PTSD or suspect that they have PTSD following a traumatic event

· Currently reside in Victoria

· Be an Australian citizen or permanent resident or have a visa status that entitles them to access public mental health services in Australia

· Have good English comprehension

· Not be currently serving in the Australian Defence Force

· Not be pregnant or breastfeeding

Unfortunately, this trial is not suitable for individuals who have been diagnosed with schizophrenia or another psychotic disorder, bipolar disorder or borderline personality disorder. It is also not suitable for individuals with a severe acquired brain injury, moderate or severe alcohol or substance use disorder or active suicidal or homicidal ideation.

*There are additional inclusion and exclusion criteria for the trial. Our intake team will assess prospective participants over the phone to confirm their eligibility.

For more information about the trial, including possible benefits and risks of participation, please read our Plain Language Statement.

This research project has been approved by the Human Research Ethics Committee of The University of Melbourne (ID Number: 29307).