Conclusions/limitations
- This first randomized, placebo-control trial of cannabis in US veterans did not show a significant difference among treatment groups, including placebo, on the primary outcome of CAPS-5 score. All 4 groups had significant reductions in symptom severity on CAPS-5 and showed good tolerability.
- Prior beliefs about the effects of cannabis may have played a role in the reduction of PTSD symptoms in the placebo group.
- Many participants (n =34) were positive for THC during the screening process, so previous cannabis use/chronicity of cannabis use may have contributed.
- One limitation was that participants assigned to the Stage 1 high THC group had Cannabis Use Disorders Identification Test scores (which assesses cannabis use disorder risk) about 2 times greater than participants in other conditions.
- Another limitation was that total cannabis use was lower than expected, as participants in Stage 1 used 8.2 g to 14.6 g over 3 weeks, though they had access to up to 37.8 g.
- There was no placebo in Stage 2.
- Future studies should look at longer treatment periods with more participants.
7. Youngstedt SD, Kline CE, Reynolds AM, et al. Bright light treatment of combat-related PTSD: a randomized controlled trial. Milit Med. 2022;187(3-4):e435-e444
Bright light therapy is an inexpensive treatment approach that may affect serotonergic pathways.16 This study examined bright light therapy for reducing PTSD symptoms and examined if improvement of PTSD is related to a shift in circadian rhythm.13
Study design
- Veterans with combat-related PTSD had to have been stable on treatment for at least 8 weeks or to have not received any other PTSD treatments prior to the study.
- Participants were randomized to active treatment of 30 minutes daily 10,000 lux ultraviolet-filtered white light while sitting within 18 inches (n = 34) or a control condition of 30 minutes daily inactivated negative ion generator (n = 35) for 4 weeks.
- Inclusion criteria included a CAPS score ≥30.
- Exclusion criteria included high suicidality, high probability of alcohol/substance abuse in the past 3 months, bipolar disorder/mania/schizophrenia/psychosis, ophthalmologic deformities, shift work in past 2 months or travel across time zones in past 2 weeks, head trauma, high outdoor light exposure, history of winter depression, history of seizures, or myocardial infarction/stroke/cancer within 3 years.
- Primary outcomes were improvement on CAPS and Clinical Global Impressions-Improvement scale (CGI-IM) score at Week 4.
- Wrist actigraphy recordings measured sleep.
- Other measurements included the Hamilton Depression Rating Scale (HAM-D), Hamilton atypical symptoms (HAM-AS), PCL-Military (PCL-M), Pittsburg Sleep Quality Index (PSQI), BDI, Spielberger State-Trait Anxiety Inventory (STAI Form Y-2), Beck Suicide Scale, and Systematic Assessment for Treatment Emergent Effects questionnaire.
Outcomes
- There was a significant decrease in CAPS score in participants who received bright light therapy compared to controls. Treatment response (defined as ≥33% reduction in score) was significantly greater in the bright light (44%) vs control (8.6%) group. No participants achieved remission.
- There was a significant improvement in CGI-IM scores in the bright light group, but no significant difference in participants who were judged to improve “much” or “very much.”
- PCL-M scores did not change significantly between groups, although a significantly greater proportion of participants had treatment response in the bright light group (33%) vs control (6%).
- There were no significant changes in HAM-D, HAM-AS, STAI, BDI, actigraphic estimates of sleep, or PSQI scores.
- Bright light therapy resulted in phase advancement while control treatment had phase delay.
- There were no significant differences in adverse effects.
Continue to: Conclusions/limitations