The Comprehensive Assessment of Neurodegeneration and Dementia (COMPASS-ND) cohort study of the Canadian Consortium on Neurodegeneration in Aging (CCNA) is a national initiative to catalyze research on dementia, set up to support the research agendas of CCNA teams. This cross-country longitudinal cohort of 2310 deeply phenotyped subjects with various forms of dementia and mild memory loss or concerns, along with cognitively intact elderly subjects, will test hypotheses generated by these teams.

The COMPASS-ND protocol, initial grant proposal for funding, fifth semi-annual CCNA Progress Report submitted to the Canadian Institutes of Health Research December 2017, and other documents supplemented by modifications made and lessons learned after implementation were used by the authors to create the description of the study provided here.

The CCNA COMPASS-ND cohort includes participants from across Canada with various cognitive conditions associated with or at risk of neurodegenerative diseases. They will undergo a wide range of experimental, clinical, imaging, and genetic investigation to specifically address the causes, diagnosis, treatment, and prevention of these conditions in the aging population. Data derived from clinical and cognitive assessments, biospecimens, brain imaging, genetics, and brain donations will be used to test hypotheses generated by CCNA research teams and other Canadian researchers. The study is the most comprehensive and ambitious Canadian study of dementia. Initial data posting occurred in 2018, with the full cohort to be accrued by 2020.

Availability of data from the COMPASS-ND study will provide a major stimulus for dementia research in Canada in the coming years.

Item 9 of the Patient Health Questionnaire-9 (PHQ-9) queries about thoughts of death and self-harm, but not suicidality. Although it is sometimes used to assess suicide risk, most positive responses are not associated with suicidality. The PHQ-8, which omits Item 9, is thus increasingly used in research. We assessed equivalency of total score correlations and the diagnostic accuracy to detect major depression of the PHQ-8 and PHQ-9.

We conducted an individual patient data meta-analysis. We fit bivariate random-effects models to assess diagnostic accuracy.

16 742 participants (2097 major depression cases) from 54 studies were included. The correlation between PHQ-8 and PHQ-9 scores was 0.996 (95% confidence interval 0.996 to 0.996). The standard cutoff score of 10 for the PHQ-9 maximized sensitivity + specificity for the PHQ-8 among studies that used a semi-structured diagnostic interview reference standard (N = 27). At cutoff 10, the PHQ-8 was less sensitive by 0.02 (−0.06 to 0.00) and more specific by 0.01 (0.00 to 0.01) among those studies (N = 27), with similar results for studies that used other types of interviews (N = 27). For all 54 primary studies combined, across all cutoffs, the PHQ-8 was less sensitive than the PHQ-9 by 0.00 to 0.05 (0.03 at cutoff 10), and specificity was within 0.01 for all cutoffs (0.00 to 0.01).

PHQ-8 and PHQ-9 total scores were similar. Sensitivity may be minimally reduced with the PHQ-8, but specificity is similar.

Most people with bipolar disorder spend a significant percentage of their lifetime experiencing either subsyndromal depressive symptoms or major depressive episodes, which contribute greatly to the high levels of disability and mortality associated with the disorder. Despite the importance of bipolar depression, there are only a small number of recognised treatment options available. Consecutive treatment failures can quickly exhaust these options leading to treatment-resistant bipolar depression (TRBD). Remarkably few studies have evaluated TRBD and those available lack a comprehensive definition of multi-therapy-resistant bipolar depression (MTRBD).

To reach consensus regarding threshold definitions criteria for TRBD and MTRBD.

Based on the evidence of standard treatments available in the latest bipolar disorder treatment guidelines, TRBD and MTRBD criteria were agreed by a representative panel of bipolar disorder experts using a modified Delphi method.

TRBD criteria in bipolar depression was defined as failure to reach sustained symptomatic remission for 8 consecutive weeks after two different treatment trials, at adequate therapeutic doses, with at least two recommended monotherapy treatments or at least one monotherapy treatment and another combination treatment. MTRBD included the same initial definition as TRBD, with the addition of failure of at least one trial with an antidepressant, a psychological treatment and a course of electroconvulsive therapy.

The proposed TRBD and MTRBD criteria may provide an important signpost to help clinicians, researchers and stakeholders in judging how and when to consider new non-standard treatments. However, some challenging diagnostic and therapeutic issues were identified in the consensus process that need further evaluation and research.

In the past 3 years, M.B. has received grant/research support from the NIH, Cooperative Research Centre, Simons Autism Foundation, Cancer Council of Victoria, Stanley Medical Research Foundation, MBF, NHMRC, Beyond Blue, Rotary Health, Geelong Medical Research Foundation, Bristol Myers Squibb, Eli Lilly, Glaxo SmithKline, Meat and Livestock Board, Organon, Novartis, Mayne Pharma, Servier, Woolworths, Avant and the Harry Windsor Foundation, has been a speaker for Astra Zeneca, Bristol Myers Squibb, Eli Lilly, Glaxo SmithKline, Janssen Cilag, Lundbeck, Merck, Pfizer, Sanofi Synthelabo, Servier, Solvay and Wyeth and served as a consultant to Allergan, Astra Zeneca, Bioadvantex, Bionomics, Collaborative Medicinal Development, Eli Lilly, Grunbiotics, Glaxo SmithKline, Janssen Cilag, LivaNova, Lundbeck, Merck, Mylan, Otsuka, Pfizer and Servier. A.J.C. has in the past 3 years received honoraria for speaking from Astra Zeneca and Lundbeck, honoraria for consulting from Allergan, Janssen, Lundbeck and LivaNova and research grant support from Lundbeck. G.M.G. holds shares in P1Vital and has served as consultant, advisor or CME speaker for Allergan, Angelini, Compass pathways, MSD, Lundbeck, Otsuka, Takeda, Medscape, Minervra, P1Vital, Pfizer, Servier, Shire and Sun Pharma. J.G. has received research funding from National Institute for Health Research, Medical Research Council, Stanley Medical Research Institute and Wellcome. H.G. received grants/research support, consulting fees or honoraria from Gedeon Richter, Genericon, Janssen Cilag, Lundbeck, Otsuka, Pfizer and Servier. R.H.M.-W. has received support for research, expenses to attend conferences and fees for lecturing and consultancy work (including attending advisory boards) from various pharmaceutical companies including Astra Zeneca, Cyberonics, Eli Lilly, Janssen, Liva Nova, Lundbeck, MyTomorrows, Otsuka, Pfizer, Roche, Servier, SPIMACO and Sunovion. R.M. has received research support from Big White Wall, Electromedical Products, Johnson and Johnson, Magstim and P1Vital. S.N. received honoraria from Lundbeck, Jensen and Otsuka. J.C.S. has received funds for research from Alkermes, Pfizer, Allergan, J&J, BMS and been a speaker or consultant for Astellas, Abbott, Sunovion, Sanofi. S.W has, within the past 3 years, attended advisory boards for Sunovion and LivaNova and has undertaken paid lectures for Lundbeck. D.J.S. has received honoraria from Lundbeck. T.S. has reported grants from Pathway Genomics, Stanley Medical Research Institute and Palo Alto Health Sciences; consulting fees from Sunovion Pharamaceuticals Inc.; honoraria from Medscape Education, Global Medical Education and CMEology; and royalties from Jones and Bartlett, UpToDate and Hogrefe Publishing. S.P. has served as a consultant or speaker for Janssen, and Sunovion. P.T. has received consultancy fees as an advisory board member from the following companies: Galen Limited, Sunovion Pharmaceuticals Europe Ltd, myTomorrows and LivaNova. E.V. received grants/ research support, consulting fees or honoraria from Abbott, AB-Biotics, Allergan, Angelini, Dainippon Sumitomo, Ferrer, Gedeon Richter, Janssen, Lundbeck, Otsuka and Sunovion. L.N.Y. has received grants/research support, consulting fees or honoraria from Allergan, Alkermes, Dainippon Sumitomo, Janssen, Lundbeck, Otsuka, Sanofi, Servier, Sunovion, Teva and Valeant. A.H.Y. has undertaken paid lectures and advisory boards for all major pharmaceutical companies with drugs used in affective and related disorders and LivaNova. He has also previously received funding for investigator-initiated studies from AstraZeneca, Eli Lilly, Lundbeck and Wyeth. P.R.A.S. has received research funding support from Corcept Therapeutics Inc. Corcept Therapeutics Inc fully funded attendance at their internal conference in California USA and all related expenses. He has received grant funding from the Medical Research Council UK for a collaborative study with Janssen Research and Development LLC. Janssen Research and Development LLC are providing non-financial contributions to support this study. P.R.A.S. has received a presentation fee from Indivior and an advisory board fee from LivaNova.

Pregnancy and childbirth are a period of high risk for women with bipolar disorder and involve difficult decisions particularly about continuing or stopping medications.

To explore what clinical predictors may help to individualise the risk of perinatal recurrence in women with bipolar disorder.

Information was gathered retrospectively by semi-structured interview, questionnaires and case-note review from 887 women with bipolar disorder who have had children. Clinical predictors were selected using backwards stepwise logistic regression, conditional permutation random forests and reinforcement learning trees.

Previous perinatal history of affective psychosis or depression was the most significant predictor of a perinatal recurrence (odds ratio (OR) = 8.5, 95% CI 5.04–14.82 and OR = 3.6, 95% CI 2.55–5.07 respectively) but even parous women with bipolar disorder without a previous perinatal mood episode were at risk following a subsequent pregnancy, with 7% developing postpartum psychosis.

Previous perinatal history of affective psychosis or depression is the most important predictor of perinatal recurrence in women with bipolar disorder and can be used to individualise risk assessments.

None.

Different diagnostic interviews are used as reference standards for major depression classification in research. Semi-structured interviews involve clinical judgement, whereas fully structured interviews are completely scripted. The Mini International Neuropsychiatric Interview (MINI), a brief fully structured interview, is also sometimes used. It is not known whether interview method is associated with probability of major depression classification.

To evaluate the association between interview method and odds of major depression classification, controlling for depressive symptom scores and participant characteristics.

Data collected for an individual participant data meta-analysis of Patient Health Questionnaire-9 (PHQ-9) diagnostic accuracy were analysed and binomial generalised linear mixed models were fit.

A total of 17 158 participants (2287 with major depression) from 57 primary studies were analysed. Among fully structured interviews, odds of major depression were higher for the MINI compared with the Composite International Diagnostic Interview (CIDI) (odds ratio (OR) = 2.10; 95% CI = 1.15–3.87). Compared with semi-structured interviews, fully structured interviews (MINI excluded) were non-significantly more likely to classify participants with low-level depressive symptoms (PHQ-9 scores ≤6) as having major depression (OR = 3.13; 95% CI = 0.98–10.00), similarly likely for moderate-level symptoms (PHQ-9 scores 7–15) (OR = 0.96; 95% CI = 0.56–1.66) and significantly less likely for high-level symptoms (PHQ-9 scores ≥16) (OR = 0.50; 95% CI = 0.26–0.97).

The MINI may identify more people as depressed than the CIDI, and semi-structured and fully structured interviews may not be interchangeable methods, but these results should be replicated.

Drs Jetté and Patten declare that they received a grant, outside the submitted work, from the Hotchkiss Brain Institute, which was jointly funded by the Institute and Pfizer. Pfizer was the original sponsor of the development of the PHQ-9, which is now in the public domain. Dr Chan is a steering committee member or consultant of Astra Zeneca, Bayer, Lilly, MSD and Pfizer. She has received sponsorships and honorarium for giving lectures and providing consultancy and her affiliated institution has received research grants from these companies. Dr Hegerl declares that within the past 3 years, he was an advisory board member for Lundbeck, Servier and Otsuka Pharma; a consultant for Bayer Pharma; and a speaker for Medice Arzneimittel, Novartis, and Roche Pharma, all outside the submitted work. Dr Inagaki declares that he has received grants from Novartis Pharma, lecture fees from Pfizer, Mochida, Shionogi, Sumitomo Dainippon Pharma, Daiichi-Sankyo, Meiji Seika and Takeda, and royalties from Nippon Hyoron Sha, Nanzando, Seiwa Shoten, Igaku-shoin and Technomics, all outside of the submitted work. Dr Yamada reports personal fees from Meiji Seika Pharma Co., Ltd., MSD K.K., Asahi Kasei Pharma Corporation, Seishin Shobo, Seiwa Shoten Co., Ltd., Igaku-shoin Ltd., Chugai Igakusha and Sentan Igakusha, all outside the submitted work. All other authors declare no competing interests. No funder had any role in the design and conduct of the study; collection, management, analysis and interpretation of the data; preparation, review or approval of the manuscript; and decision to submit the manuscript for publication.

Low birth weight has been inconsistently associated with risk of developing affective disorders, including major depressive disorder (MDD). To date, studies investigating possible associations between birth weight and bipolar disorder (BD), or personality traits known to predispose to affective disorders such as neuroticism, have not been conducted in large cohorts.

To assess whether very low birth weight (<1500 g) and low birth weight (1500–2490 g) were associated with higher neuroticism scores assessed in middle age, and lifetime history of either MDD or BD. We controlled for possible confounding factors.

Retrospective cohort study using baseline data on the 83 545 UK Biobank participants with detailed mental health and birth weight data. Main outcomes were prevalent MDD and BD, and neuroticism assessed using the Eysenck Personality Inventory Neuroticism scale - Revised (EPIN-R)

Referent to normal birth weight, very low/low birth weight were associated with higher neuroticism scores, increased MDD and BD. The associations between birth weight category and MDD were partially mediated by higher neuroticism.

These findings suggest that intrauterine programming may play a role in lifetime vulnerability to affective disorders.

Sleep loss may trigger mood episodes in people with bipolar disorder but individual differences could influence vulnerability to this trigger.

To determine whether bipolar subtype (bipolar disorder type I (BP-I) or II (BD-II)) and gender were associated with vulnerability to the sleep loss trigger.

During a semi-structured interview, 3140 individuals (68% women) with bipolar disorder (66% BD-I) reported whether sleep loss had triggered episodes of high or low mood. DSM-IV diagnosis of bipolar subtype was derived from case notes and interview data.

Sleep loss triggering episodes of high mood was associated with female gender (odds ratio (OR) = 143, 95% CI 1.17–1.75, P<0.001) and BD-I subtype (OR=2.81, 95% CI 2.26–3.50, P<0.001). Analyses on sleep loss triggering low mood were not significant following adjustment for confounders.

Gender and bipolar subtype may increase vulnerability to high mood following sleep deprivation. This should be considered in situations where patients encounter sleep disruption, such as shift work and international travel.