The present study was conducted to investigate cannabis use profiles and self-perceived symptom improvement for insomnia in individuals with depression, anxiety, and comorbid anxiety and depression through crowdsourced health data. Self-reported scores before and after cannabis use indicate a significant self-perceived benefit with the use of cannabinoids for insomnia. These findings are consistent with preliminary results from clinical trials, suggesting that cannabis may be a future option for insomnia management [23].
In our study, all cannabis strains were perceived to improve insomnia by individuals with depression, anxiety, and comorbid depression and anxiety; however, in individuals with depression, CBD-dominant products were felt to be less efficacious than indica-dominant, indica hybrid, and sativa-dominant strains to improve insomnia. This could suggest that individuals with depression have a distinct response profile to CBD for insomnia, and/or CBD might exert anxiolytic effects in individuals with anxiety and comorbid depression/anxiety, which, in turn, may improve sleep. Interestingly, previous studies have suggested that insomnia may have independent relationships with depression and anxiety [5] and it is possible that this finding is a result of distinct pathways for the relationships between depression and insomnia, and between anxiety and insomnia, respectively. Previous research suggests that insomnia could have etiologically distinct directional associations with anxiety versus depression, supporting the hypothesis that the nature of the relationship between insomnia and mental disorders may be different depending on the comorbid condition [5]. These results are in line with the varying responses to cannabis for insomnia in anxiety versus depression in our study.
Notably, our study also compared the self-perceived efficacy of cannabis for insomnia symptoms across all age ranges. The current literature on the influence of age in cannabis and sleep outcomes is relatively scarce. However, the function of the endocannabinoid system in circadian rhythms has been well-established and emerging evidence has highlighted its potential modulating role in the regulation of sleep within the context of aging [24,25,26]. There are also reports of differences in the pharmacokinetics of cannabis with increased age, which may potentially influence how the drug is absorbed in older adults [24, 26,27,28]. As younger adults have faster basal metabolisms, it has been theorized that differences in cannabis-related effects across age groups may be explained by the unique biological effects of aging [24, 29]. Furthermore, previous studies examining sleep across age has consistently reported decreases in sleep quality, shorter sleep times, and more fragmented sleep with older adults [26, 30, 31]. Some studies have also reported age-related variability in the presentation of symptoms of major depressive disorder, with older adults reporting more sleep-related depressive symptomology, including problems sleeping during the night and more early morning awakenings [32]. Though cannabis was perceived efficacious across most age groups in our study, this was not true for older adults in the depressive group.
Despite the potential benefits of cannabinoids for insomnia, research in the field lacks placebo-controlled trials that assess self-perceived symptom improvement alongside risks and harms. Though some studies suggest that administration of THC and THC-derivatives, alone or in combination with CBD may improve sleep outcomes, very few clinical studies have objectively investigated the efficacy of cannabis for sleep using validated measures and sleep as a primary outcome [20,21,22]. Large placebo-controlled trials using both objective and subjective measures of sleep parameters are warranted. Additionally, given the highly comorbid nature of depression, anxiety, and sleep disorders, placebo-controlled trials investigating the use of cannabis for the management of insomnia in these populations are encouraged.
Limitations
The present study has several limitations. First, reported conditions and symptoms were determined subjectively by individuals; as a result, it is unclear whether all individuals meet full diagnostic criteria for these conditions. Importantly, the lack of an objective measure of insomnia in our study is a main limitation. Although insomnia severity in the present study is measured on a 0–10-point scale, insomnia may manifest itself in different ways that were not captured with this app. Furthermore, Strainprint® collects a very specific set of information from each individual. Any additional data that may influence symptom improvement outcomes (e.g., medical history, concurrent medications, etc.) were not able to be assessed. The present study may also involve some sampling bias. As Strainprint® is largely marketed to cannabis users, resulting samples may underrepresent individuals who find cannabis to be ineffective and overrepresent those who benefit from its use. Moreover, information on potential side effects is lacking; therefore, any data regarding negative subject experiences from cannabis use are inaccessible. Additionally, the current study examined strain categories, though differences between categories remain largely controversial [33,34,35]. Among consumers, different strains are often associated with various perceived effects [36]; however, many researchers maintain that any perceived effects are a result of other components of cannabis (ex. terpenes) which are not typically reported to consumers [33, 34]. As such, it is possible that perceived effects reported in this study are a result of interactions between various cannabis components rather than individual strains specifically. Nonetheless, in the absence of robust RCTs, investigations of perceived effects of strain categories in naturalistic settings can improve understanding of consumer purchasing decisions [37], as well as inform future trial designs.
Despite its limitations, this study is strengthened by its large, naturalistic sample. Individuals were also prompted to record cannabis use in their daily environments, maximizing ecological validity of the study. As such, large mobile health studies of this sort are considerably more convenient and provide real-time information. Although in real life many people report using cannabis use for depression, anxiety and sleep, this area of research is still relatively scarce. As such, results from the naturalistic study can provide a better understanding of cannabis usage profiles for insomnia, while providing valuable information for future trials designed to evaluate efficacy and safety of cannabis for therapeutic purposes.