BMJ mental health最新文献

Background: Reasons for first using cannabis (RFUC) may influence later use patterns and mental health outcomes. However, limited research has explored self-medication versus social RFUCs in depth, and their associations with cannabis use patterns and psychopathology in the general population.

Objectives: We examined RFUCs and their associations with (1) reasons for continuing cannabis use, (2) weekly THC (delta-9-tetrahydrocannabinol) unit consumption and (3) symptoms of paranoia, anxiety and depressive symptoms.

Methods: We analysed data from the Cannabis&Me (CAMe) population survey (March 2022-July 2024), including 2573 (75.9%) current and 816 (24.1%) past cannabis users aged 18 years or older.

Findings: Participants reported a mean weekly consumption of 206 THC units (SD=268). Initiating cannabis use for anxiety (β=36.22, p=3.3e-03), depression (β=40.37, p=1.74e-03) or because 'family members were using it' (β=87.43, p=1.22e-09) was associated with higher weekly THC units. RFUC to relieve physical discomfort (β=8.89, p=4.12e-07), pain (β=7.24, p=5.56e-06), anxiety (β=9.67, p=1.63e-16), depression (β=9.12, p=1.21e-13) and minor psychotic symptoms (β=16.46, p=1.2e-04) were linked to higher paranoia scores. Similar associations were observed for anxiety and depression. Conversely, starting for fun (β=-3.71, p=3.49e-05) or curiosity (β=-2.61, p=5e-03) was associated with lower paranoia and anxiety. RFUC for 'boredom' was linked to increased depression (β=1.09, p=3.8e-03).

Conclusions: Initiating cannabis use for self-medication is associated with higher average THC consumption, and increased anxiety, depression and paranoia.

Clinical implications: Asking individuals why they first used cannabis may serve as a cost-effective screening tool to identify those who could benefit from monitoring, support, or referral to intervention services.

Question: How effective is pharmacogenomic (PGx)-guided antidepressant treatment compared with treatment-as-usual (TAU) in major depressive disorder (MDD), and how do ethnicity, disease severity and genetic panel scope influence outcomes?

Study selection and analysis: This systematic review and meta-analysis comprised 13 randomised controlled trials (2013-2024) comparing PGx-guided therapy with TAU in MDD. PubMed, Ovid Embase, Ovid Medline, Ovid PsycINFO and the Cochrane Library were searched up to December 2024. Outcomes included response and remission rates at 8 and 12 weeks. Subgroup analyses examined ethnicity and MDD severity. Cumulative meta-analyses assessed gene panel size. The pooled risk ratios (RRs) with 95% CIs were calculated to estimate the overall effect.

Findings: PGx-guided treatment significantly improved response rates at 8 weeks (RR 1.23, 95% CI 1.05 to 1.43) and 12 weeks (RR 1.29, 95% CI 1.17 to 1.43). Remission was significant at 8 weeks (RR 1.37, 95% CI 1.19 to 1.57) but not at 12 weeks (RR 1.56, 95% CI 0.93 to 2.61). Benefits appeared stronger in the Asian country subgroup compared with non-Asian country subgroup (interaction p=0.02), but this requires validation due to the smaller Asian country sample size. No significant subgroup differences were observed between the MDD not-specified and MDD difficult-to-treat subgroups, despite the latter demonstrating significant improvements in both response and remission rates with PGx-guided treatment compared with TAU at 8 weeks. Cumulative analyses showed effect sizes plateaued, with broader panels offering minimal incremental gains.

Conclusions: PGx-guided treatment seems to offer moderate benefits for antidepressant efficacy, with potential advantages in Asian and difficult-to-treat subgroups. Genetic and ethnic variability in drug metabolism underscores the need for population-specific approaches. While multigene panels show clinical benefits plateau, suggesting cost-benefit optimisation is critical. Future research should address adverse events, the cost-effectiveness of expanded panels, long-term remission outcomes and treatment efficacy across more precisely stratified disease severity levels to maximise clinical relevance.

Prospero registration number: CRD42024570014.

Background: Electrodermal activity (EDA) is a measure of sympathetic arousal that has been linked to depression in laboratory experiments. However, the inability to measure EDA passively over time and in the real world has limited conclusions that can be drawn about EDA as an indicator of mental health status outside of controlled settings.

Objective: Recent smartwatches have begun to incorporate wrist-worn continuous EDA sensors that enable longitudinal measurement of sympathetic arousal in everyday life. This work (n=237, 4-week observation period) examines the association between passively collected, diurnal variations in EDA and symptoms of depression, anxiety and perceived stress in a large community sample.

Methods: We conducted a prospective, non-randomised study to investigate patterns and relationships between digital device use patterns, including sensor data from phones and wearables reflecting both behavioural and physiological processes, and self-reported measures of mental health and well-being. We recruited 395 participants who had a Fitbit Sense 2 device with the electrodermal sensor activated. We use a non-linear cosinor fitting method to estimate the difference in mesor, amplitude and phase, between the diurnal rhythms in heart rate (HR), heart rate variability (HRV) root mean square of successive differences, EDA, skin temperature and steps.

Findings: Subjects who exhibited elevated depressive and anxiety symptoms had higher tonic EDA, skin temperature and heart rate, despite not engaging in greater physical activity, compared with those that were not depressed or anxious. In contrast, subjects who exhibited elevated stress only exhibited higher skin temperature. Most strikingly, differences in EDA between those with high versus low symptoms were most prominent during the early morning. We did not observe amplitude or phase differences in the diurnal patterns.

Conclusions: Results indicate that participants with elevated depressive and anxiety symptoms have different diurnal physiological patterns. Specifically, EDA differences suggest elevated sympathetic activity throughout the day and in particular in the early morning.

Clinical implications: Our work suggests that electrodermal sensors may be practical and useful in measuring the physiological correlates of mental health symptoms in free-living contexts and that recent consumer smartwatches might be a tool for doing so.

This editorial discusses the importance of maintaining diversity within science, noting especially its significance to research in psychiatry. It follows a recent directive that was issued by the US administration that places unreasonable constraints on US government-funded scientific inquiry. The article draws attention to the harmful intended consequences of the directive. It also discusses its unintended consequences, which are likely to be damaging because heterogeneity is inherent in nature, and recognition of diversity in medical science helps achieve specificity. This is essential for the detection and diagnosis of disease and for tailoring therapies and developing targeted treatments.