Hannah Sallis

Daily use, especially of high-potency cannabis, drives the earlier onset of psychosis in cannabis users.

UNLABELLED Cannabis use is associated with an earlier age of onset of psychosis (AOP). However, the reasons for this remain debated. METHODS We applied a Cox proportional hazards model to 410 first-episode psychosis patients to investigate the association between gender, patterns of cannabis use, and AOP. RESULTS Patients with a history of cannabis use presented with their first episode of psychosis at a younger age (mean years = 28.2, SD = 8.0; median years = 27.1) than those who never used cannabis (mean years = 31.4, SD = 9.9; median years = 30.0; hazard ratio [HR] = 1.42; 95% CI: 1.16-1.74; P < .001). This association remained significant after controlling for gender (HR = 1.39; 95% CI: 1.11-1.68; P < .001). Those who had started cannabis at age 15 or younger had an earlier onset of psychosis (mean years = 27.0, SD = 6.2; median years = 26.9) than those who had started after 15 years (mean years = 29.1, SD = 8.5; median years = 27.8; HR = 1.40; 95% CI: 1.06-1.84; P = .050). Importantly, subjects who had been using high-potency cannabis (skunk-type) every day had the earliest onset (mean years = 25.2, SD = 6.3; median years = 24.6) compared to never users among all the groups tested (HR = 1.99; 95% CI: 1.50- 2.65; P < .0001); these daily users of high-potency cannabis had an onset an average of 6 years earlier than that of non-cannabis users. CONCLUSIONS Daily use, especially of high-potency cannabis, drives the earlier onset of psychosis in cannabis users.

Confirmation that the AKT1 (rs2494732) Genotype Influences the Risk of Psychosis in Cannabis Users

BACKGROUND Cannabis use is associated with an increased risk of psychosis. One study has suggested that genetic variation in the AKT1 gene might influence this effect. METHODS In a case-control study of 489 first-episode psychosis patients and 278 control subjects, we investigated the interaction between variation at the AKT1 rs2494732 single nucleotide polymorphism and cannabis use in increasing the risk of psychosis. RESULTS The rs2494732 locus was not associated with an increased risk of a psychotic disorder, with lifetime cannabis use, or with frequency of use. We did, however, find that the effect of lifetime cannabis use on risk of psychosis was significantly influenced by the rs2494732 locus (likelihood ratio statistic for the interaction = 8.54; p = .014). Carriers of the C/C genotype with a history of cannabis use showed a greater than twofold increased likelihood of a psychotic disorder (odds ratio = 2.18 [95% confidence interval: 1.12, 4.31]) when compared with users who were T/T carriers. Moreover, the interaction between the rs2494732 genotype and frequency of use was also significant at the 5% level (likelihood ratio = 13.39; p = .010). Among daily users, C/C carriers demonstrated a sevenfold increase in the odds of psychosis compared with T/T carriers (odds ratio = 7.23 [95% confidence interval: 1.37, 38.12]). CONCLUSIONS Our findings provide strong support for the initial report that genetic variation at rs2494732 of AKT1 influences the risk of developing a psychotic disorder in cannabis users.

Perinatal depression and omega-3 fatty acids: A Mendelian randomisation study

Background There have been numerous studies investigating the association between omega-3 fatty acids (FAs) and depression, with mixed findings. We propose an approach which is largely free from issues such as confounding or reverse causality, to investigate this relationship using observational data from a pregnancy cohort. Methods The Avon Longitudinal Study of Parents and Children (ALSPAC) cohort collected information on FA levels from antenatal blood samples and depressive symptoms at several time points during pregnancy and the postnatal period. Conventional epidemiological analyses were used in addition to a Mendelian randomisation (MR) approach to investigate the association between levels of two omega-3 FAs (docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA)) and perinatal onset depression, antenatal depression (AND) and postnatal depression (PND). Results Weak evidence of a positive association with both EPA (OR=1.07; 95% CI: 0.99–1.15) and DHA (OR=1.08; 95% CI: 0.98–1.19) with perinatal onset depression was found using a multivariable logistic regression adjusting for social class and maternal age. However, the strength of association was found to attenuate when using an MR analysis to investigate DHA. Limitations Pleiotropy is a potential limitation in MR analyses; we assume that the genetic variants included in the instrumental variable are associated only with our trait of interest (FAs) and thus cannot influence the outcome via any other pathway. Conclusions We found weak evidence of a positive association between omega-3 FAs and perinatal onset depression. However, without confirmation from the MR analysis, we are unable to draw conclusions regarding causality.

Low Birth Weight in the Offspring of Women With Anorexia Nervosa

A growing body of literature has investigated the association between maternal anorexia nervosa and pregnancy outcomes. Infant low birth weight is associated with a number of neurodevelopmental and physical sequelae; however, consistent results on its association with maternal anorexia nervosa are scant. Therefore, a systematic review and meta-analysis of the existing literature were undertaken. PubMed, Embase, and PsychInfo were searched for studies comparing the mean birth weight of babies delivered by mothers with (a history of) anorexia nervosa against those of healthy mothers. Studies were excluded from the meta-analysis if not presenting data from an unexposed comparison group and if using multiple eating disorders as exposure without presenting individual results. Fourteen studies were included in the systematic review and 9 in the meta-analysis, undertaken between 1999 and 2012 in Denmark, the Netherlands, New Zealand, Norway, Sweden, and the United Kingdom. Birth weights were standardized by dividing the difference in mean birth weight by the pooled standard deviation (equivalent to Cohens d). Results showed a standardized mean difference of -0.19 kg (95% confidence interval: -0.25, -0.15; P = 0.01) in the birth weight of children of mothers with anorexia nervosa, and some bias in favor of papers presenting lower birth weight results for exposed mothers was detected. However, the small power of the analysis due to the small number of available studies and, thus, chance could partially account for this result. Our results confirm that maternal anorexia nervosa predicts lower birth weight and, despite some limitations, they have important clinical implications for prevention of adverse child outcomes.

A systematic review of obstetric complications as risk factors for eating disorder and a meta-analysis of delivery method and prematurity

OBJECTIVE The aim of this study was to systematically review the literature on obstetric factors at birth and their role as risk factors for a subsequent eating disorder (ED) and where possible to perform a meta-analysis of case-control studies of EDs and obstetric complications (OCs). METHOD Studies were ascertained by computer searches of electronic databases (Medline, PsycINFO, Web of Science and CINAHL), searches of reference lists and from raw data obtained upon request from the authors. A total of 14 studies were identified for the systematic review, of which 6 were eligible for the subsequent meta-analysis. Of the selected 6 studies, 5 reported on the same OCs, namely vaginal instrumental delivery and prematurity. Accordingly, meta-analyses were run on these two variables. Both analyses were conducted on anorexia nervosa (AN) patients. RESULTS Findings from the systematic review were conflicting, with some studies reporting a significant relationship between OCs and ED diagnoses and/or ED symptomatology and others refuting it. A non-significant association of instrumental delivery [pooled odds ratio (OR) 1.06, 95%CI: 0.69, 1.65] and prematurity [pooled OR 1.17, 95%CI: 0.91, 1.52] with AN was revealed in our meta-analysis. CONCLUSION The current literature on OCs as risk factors for a later ED is contradictory. The range of different occurrences considered as OCs and methodological limitations hinder ultimate conclusions. Upcoming studies should pool datasets together to obtain sufficient power to assess OCs and EDs in combination.

ω-3 Fatty acids for major depressive disorder in adults: an abridged Cochrane review

Objective To assess the effects of n-3 polyunsaturated fatty acids (n-3PUFAs; also known as ω-3 fatty acids) compared with comparator for major depressive disorder (MDD) in adults. Design Systematic review and meta-analyses. Data sources The Cochrane Depression, Anxiety and Neurosis Review Groups Specialised Registers (CCDANCTR) and International Trial Registries searched to May 2015. CINAHL searched to September 2013. Trial selection Inclusion criteria: a randomised controlled trial (RCT); that provided n-3PUFAs as an intervention; used a comparator; measured depressive symptomology as an outcome; and was conducted in adults with MDD. Outcomes Primary outcomes were depressive symptomology and adverse events. Results 20 trials encompassing 26 relevant studies were found. For n-3PUFAs versus placebo, n-3PUFA supplementation resulted in a small-to-modest benefit for depressive symptomology: SMD=−0.32 (95% CI −0.52 to −0.12; 25 studies, 1373 participants, very low-quality evidence), but this effect is unlikely to be clinically meaningful, is very imprecise and, based on funnel plot inspection, sensitivity analyses and comparison with large well-conducted trials, is likely to be biased. Considerable evidence of heterogeneity between studies was also found, and was not explained by subgroup or sensitivity analyses. Numbers of individuals experiencing adverse events were similar in intervention and placebo groups (OR=1.24, 95% CI 0.95 to 1.62; 19 studies, 1207 participants; very low-quality evidence). For n-3PUFAs versus antidepressants, no differences were found between treatments in depressive symptomology (MD=−0.70 (95% CI −5.88 to 4.48); 1 study, 40 participants, very low-quality evidence). Conclusions At present, we do not have sufficient evidence to determine the effects of n-3PUFAs as a treatment for MDD. Further research in the form of adequately powered RCTs is needed.

Telephone-based guided self-help for adolescents with chronic fatigue syndrome: A non-randomised cohort study

The aim of this study was to gain preliminary evidence about the efficacy of a new telephone-based guided self-help intervention, based on cognitive-behavioural principles, which aimed to reduce fatigue and improve school attendance in adolescents with chronic fatigue syndrome (CFS). A non-randomised cohort design was used, with a two-month baseline period. Sixty-three 11-18 year-old participants recruited from a specialist CFS unit received the intervention. Participants received six half-hour fortnightly telephone sessions and two follow-up sessions. Fatigue and school attendance were the main outcomes and the main time point for assessing outcome was 6 months post-treatment. Using multi-level modelling, a significant decrease in fatigue was found between pre-treatment and 6 month follow-up, treatment effect estimate = - 5.68 (-7.63, -3.72), a large effect size (Cohens d = 0.79). The decrease in fatigue between pre and post-treatment was significantly larger than between baseline and pre-treatment. A significant increase in school attendance was found between pre-treatment and 6 month follow-up, effect estimate = 1.38 (0.76, 2.00), a medium effect size (d = -0.48). univariate logistic regression found baseline perfectionism to be associated with better [corrected] school attendance at six-month follow-up. In conclusion, telephone-based guided self-help is an acceptable minimal intervention which is efficacious in reducing fatigue in adolescents with CFS.

Interaction between cannabis consumption and childhood abuse in psychotic disorders: preliminary findings on the role of different patterns of cannabis use

Several studies have suggested that lifetime cannabis consumption and childhood abuse synergistically contribute to the risk for psychotic disorders. This study aimed to extend existing findings regarding an additive interaction between childhood abuse and lifetime cannabis use by investigating the moderating role of type and frequency of cannabis use.

Interaction between cannabis consumption and childhood abuse in psychotic disorders

Several studies have suggested that lifetime cannabis consumption and childhood abuse synergistically contribute to the risk for psychotic disorders. This study aimed to extend existing findings regarding an additive interaction between childhood abuse and lifetime cannabis use by investigating the moderating role of type and frequency of cannabis use.

Confirmatory factor analysis for two questionnaires of caregiving in eating disorders.

Objective: Caring for someone diagnosed with an eating disorder (ED) is associated with a high level of burden and psychological distress which can inadvertently contribute to the maintenance of the illness. The Eating Disorders Symptom Impact Scale (EDSIS) and Accommodation and Enabling Scale for Eating Disorders (AESED) are self-report scales to assess elements of caregiving theorised to contribute to the maintenance of an ED. Further validation and confirmation of the factor structures for these scales are necessary for rigorous evaluation of complex interventions which target these modifiable elements of caregiving. Method: EDSIS and AESED data from 268 carers of people with anorexia nervosa (AN), recruited from consecutive admissions to 15 UK inpatient or day patient hospital units, were subjected to confirmatory factor analysis to test model fit by applying the existing factor structures: (a) four-factor structure for the EDSIS and (b) five-factor structure for the AESED. Results: Confirmatory factor analytic results support the existing four-factor and five-factor structures for the EDSIS and the AESED, respectively. Discussion: The present findings provide further validation of the EDSIS and the AESED as tools to assess modifiable elements of caregiving for someone with an ED.