Prevalence estimates of neurodevelopmental disorders (ND) are essential for treatment planning. However, epidemiological research has yielded highly variable rates across countries, including Spain. This study examined the prevalence and sociodemographic correlates of ND in a school sample of Spanish children and adolescents.

The Child Behaviour Checklist/Teacher's Report Form/Youth Self-Report and the Conners' Rating Scales were administered for screening purposes. Additionally, teachers provided information on reading and writing difficulties. Subjects who screened positive were interviewed for diagnostic confirmation according to the Diagnostic and Statistical Manual of Mental Disorders criteria. The final population comprised 6834 students aged 5–17. Multivariate analyses were performed to determine the influence of gender, age, educational stage, school type, socioeconomic status (SES), and ethnicity on the prevalence estimates.

A total of 1249 (18.3%) subjects met criteria for at least one ND, although only 423 had already received a diagnosis. Specifically, the following prevalence rates were found: intellectual disabilities (ID), 0.63%; communication disorders, 1.05%; autism spectrum disorder (ASD), 0.70%; attention-deficit/hyperactivity disorder (ADHD), 9.92%; specific learning disorder (SLD), 10.0%; and motor disorders, 0.76%. Students of foreign origin and from low SES evidenced higher odds of having ID. Boys were more likely to display ASD or a motor disorder. Age, SES, and ethnicity were significant predictors for SLD, while communication disorders and ADHD were also associated with gender.

The prevalence of ND among Spanish students is consistent with international studies. However, a substantial proportion had never been previously diagnosed, which emphasise the need for early detection and intervention programmes.

Depression is strongly associated with chronic disease; yet, the direction of this relationship is poorly understood. Allostatic load (AL) provides a framework for elucidating depression-disease pathways. We aimed to investigate bidirectional, longitudinal associations of baseline depressive symptoms or AL with 5-year AL or depressive symptoms, respectively.

Data were from baseline, 2-year, and 5-year visits of 620 adults (45–75 years) enrolled in the Boston Puerto Rican Health Study. The Center for Epidemiology Studies Depression (CES-D) scale (0–60) captured depressive symptoms, which were categorized at baseline as low (<8), subthreshold (8–15), or depression-likely (⩾16) symptoms. AL was calculated from 11 parameters of biological functioning, representing five physiological systems. Baseline AL scores were categorized by the number of dysregulated parameters: low (0–2), moderate (3–5), or high (⩾6) AL. Multivariable, multilevel random intercept and slope linear regression models were used to examine associations between 3-category baseline CES-D score and 5-year continuous AL score, and between baseline 3-category AL and 5-year continuous CES-D score.

Baseline subthreshold depressive symptoms [(mean (95% CI)): 4.8 (4.5–5.2)], but not depression-likely symptoms [4.5 (4.2–4.9)], was significantly associated with higher 5-year AL scores, compared to low depressive symptoms [4.3 (3.9–4.7)]. Baseline high AL [19.4 (17.6–21.2)], but not low AL [18.5 (16.5–20.6)], was significantly associated with higher 5-year CES-D score, compared to baseline moderate AL [16.9 (15.3–18.5)].

Depressive symptoms and AL had a bi-directional relationship over time, indicating a nuanced pathway linking depression with chronic diseases among a minority population.

Sex-related differences in psychopathology are known phenomena, with externalizing and internalizing symptoms typically more common in boys and girls, respectively. However, the neural correlates of these sex-by-psychopathology interactions are underinvestigated, particularly in adolescence.

Participants were 14 years of age and part of the IMAGEN study, a large (N = 1526) community-based sample. To test for sex-by-psychopathology interactions in structural grey matter volume (GMV), we used whole-brain, voxel-wise neuroimaging analyses based on robust non-parametric methods. Psychopathological symptom data were derived from the Strengths and Difficulties Questionnaire (SDQ).

We found a sex-by-hyperactivity/inattention interaction in four brain clusters: right temporoparietal-opercular region (p < 0.01, Cohen's d = −0.24), bilateral anterior and mid-cingulum (p < 0.05, Cohen's d = −0.18), right cerebellum and fusiform (p < 0.05, Cohen's d = −0.20) and left frontal superior and middle gyri (p < 0.05, Cohen's d = −0.26). Higher symptoms of hyperactivity/inattention were associated with lower GMV in all four brain clusters in boys, and with higher GMV in the temporoparietal-opercular and cerebellar-fusiform clusters in girls.

Using a large, sex-balanced and community-based sample, our study lends support to the idea that externalizing symptoms of hyperactivity/inattention may be associated with different neural structures in male and female adolescents. The brain regions we report have been associated with a myriad of important cognitive functions, in particular, attention, cognitive and motor control, and timing, that are potentially relevant to understand the behavioural manifestations of hyperactive and inattentive symptoms. This study highlights the importance of considering sex in our efforts to uncover mechanisms underlying psychopathology during adolescence.

Cigarette smoking is associated with worse cognition and decreased cortical volume and thickness in healthy cohorts. Chronic cigarette smoking is prevalent in schizophrenia spectrum disorders (SSD), but the effects of smoking status on the brain and cognition in SSD are not clear. This study aimed to understand whether cognitive performance and brain morphology differed between smoking and non-smoking individuals with SSD compared to healthy controls.

Data were obtained from the Australian Schizophrenia Research Bank. Cognitive functioning was measured in 299 controls and 455 SSD patients. Cortical volume, thickness and surface area data were analysed from T1-weighted structural scans obtained in a subset of the sample (n = 82 controls, n = 201 SSD). Associations between smoking status (cigarette smoker/non-smoker), cognition and brain morphology were tested using analyses of covariance, including diagnosis as a moderator.

No smoking by diagnosis interactions were evident, and no significant differences were revealed between smokers and non-smokers across any of the variables measured, with the exception of a significantly thinner left posterior cingulate in smokers compared to non-smokers. Several main effects of smoking in the cognitive, volume and thickness analyses were initially significant but did not survive false discovery rate (FDR) correction.

Despite the general absence of significant FDR-corrected findings, trend-level effects suggest the possibility that subtle smoking-related effects exist but were not uncovered due to low statistical power. An investigation of this topic is encouraged to confirm and expand on our findings.

Freeman et al. (2020a, Psychological Medicine, 21, 1–13) argue that there is widespread support for coronavirus conspiracy theories in England. We hypothesise that their estimates of prevalence are inflated due to a flawed research design. When asking respondents to their survey to agree or disagree with pro-conspiracy statements, they used a biased set of response options: four agree options and only one disagree option (and no ‘don't know’ option). We also hypothesise that due to these flawed measures, the Freeman et al. approach under-estimates the strength of the correlation between conspiracy beliefs and compliance. Finally, we hypothesise that, due to reliance on bivariate correlations, Freeman et al. over-estimate the causal connection between conspiracy beliefs and compliance.

In a pre-registered study, we conduct an experiment embedded in a survey of a representative sample of 2057 adults in England (fieldwork: 16−19 July 2020).

Measured using our advocated ‘best practice’ approach (balanced response options, with a don't know option), prevalence of support for coronavirus conspiracies is only around five-eighths (62.3%) of that indicated by the Freeman et al. approach. We report mixed results on our correlation and causation hypotheses.

To avoid over-estimating prevalence of support for coronavirus conspiracies, we advocate using a balanced rather than imbalanced set of response options, and including a don't know option.

Our aim was to estimate provisional willingness to receive a coronavirus 2019 (COVID-19) vaccine, identify predictive socio-demographic factors, and, principally, determine potential causes in order to guide information provision.

A non-probability online survey was conducted (24th September−17th October 2020) with 5,114 UK adults, quota sampled to match the population for age, gender, ethnicity, income, and region. The Oxford COVID-19 vaccine hesitancy scale assessed intent to take an approved vaccine. Structural equation modelling estimated explanatory factor relationships.

71.7% (n=3,667) were willing to be vaccinated, 16.6% (n=849) were very unsure, and 11.7% (n=598) were strongly hesitant. An excellent model fit (RMSEA=0.05/CFI=0.97/TLI=0.97), explaining 86% of variance in hesitancy, was provided by beliefs about the collective importance, efficacy, side-effects, and speed of development of a COVID-19 vaccine. A second model, with reasonable fit (RMSEA=0.03/CFI=0.93/TLI=0.92), explaining 32% of variance, highlighted two higher-order explanatory factors: ‘excessive mistrust’ (r=0.51), including conspiracy beliefs, negative views of doctors, and need for chaos, and ‘positive healthcare experiences’ (r=−0.48), including supportive doctor interactions and good NHS care. Hesitancy was associated with younger age, female gender, lower income, and ethnicity, but socio-demographic information explained little variance (9.8%). Hesitancy was associated with lower adherence to social distancing guidelines.

COVID-19 vaccine hesitancy is relatively evenly spread across the population. Willingness to take a vaccine is closely bound to recognition of the collective importance. Vaccine public information that highlights prosocial benefits may be especially effective. Factors such as conspiracy beliefs that foster mistrust and erode social cohesion will lower vaccine up-take.

We sought to provide the first point prevalence estimates of muscle dysmorphia (MD), a form of body dysmorphic disorder characterized by a preoccupation with perceived insufficient muscularity, in adolescents.

Data were taken from a survey of 3618 Australian adolescents (11.172–19.76 years; 49.3% girls). Measures captured demographic characteristics, symptoms of MD and eating disorders, psychological distress and functional impairment. Diagnostic criteria for MD developed by Pope et al. (1997, Psychosomatics, 38(6), 548–557) were applied, entailing preoccupation with insufficient muscularity causing significant levels of distress or disability that cannot be better accounted for by an eating disorder.

The point prevalence of MD was 2.2% [95% confidence interval (CI) 1.6–3.0%] among boys and 1.4% (95% CI 0.9–2.0%) among girls. Prevalence was not associated with gender (V = 0.031) or socioeconomic status (SES) (partial η2 < 0.001), but was marginally associated with older age (partial η2 = 0.001). Boys with MD were more likely than girls with MD to report severe preoccupation with muscularity (V = 0.259) and a weight-lifting regime that interfered with their life (V = 0.286), whereas girls with MD were more likely to report discomfort with body exposure (V = 0.380).

While future epidemiological research using diagnostic interviews is needed to verify these estimates, the findings suggest that MD is relatively common from early to late adolescence. Gender differences in MD prevalence may be minimal; however, the symptom profile appears to diverge between boys and girls. These findings provide a platform for future, analytical research designed to inform clinical and public health interventions.

A recent genome-wide association study (GWAS) identified 12 independent loci significantly associated with attention-deficit/hyperactivity disorder (ADHD). Polygenic risk scores (PRS), derived from the GWAS, can be used to assess genetic overlap between ADHD and other traits. Using ADHD samples from several international sites, we derived PRS for ADHD from the recent GWAS to test whether genetic variants that contribute to ADHD also influence two cognitive functions that show strong association with ADHD: attention regulation and response inhibition, captured by reaction time variability (RTV) and commission errors (CE).

The discovery GWAS included 19 099 ADHD cases and 34 194 control participants. The combined target sample included 845 people with ADHD (age: 8–40 years). RTV and CE were available from reaction time and response inhibition tasks. ADHD PRS were calculated from the GWAS using a leave-one-study-out approach. Regression analyses were run to investigate whether ADHD PRS were associated with CE and RTV. Results across sites were combined via random effect meta-analyses.

When combining the studies in meta-analyses, results were significant for RTV (R2 = 0.011, β = 0.088, p = 0.02) but not for CE (R2 = 0.011, β = 0.013, p = 0.732). No significant association was found between ADHD PRS and RTV or CE in any sample individually (p > 0.10).

We detected a significant association between PRS for ADHD and RTV (but not CE) in individuals with ADHD, suggesting that common genetic risk variants for ADHD influence attention regulation.

Assessment of risks of illnesses has been an important part of medicine for decades. We now have hundreds of ‘risk calculators’ for illnesses, including brain disorders, and these calculators are continually improving as more diverse measures are collected on larger samples.

We first replicated an existing psychosis risk calculator and then used our own sample to develop a similar calculator for use in recruiting ‘psychosis risk’ enriched community samples. We assessed 632 participants age 8–21 (52% female; 48% Black) from a community sample with longitudinal data on neurocognitive, clinical, medical, and environmental variables. We used this information to predict psychosis spectrum (PS) status in the future. We selected variables based on lasso, random forest, and statistical inference relief; and predicted future PS using ridge regression, random forest, and support vector machines.

Cross-validated prediction diagnostics were obtained by building and testing models in randomly selected sub-samples of the data, resulting in a distribution of the diagnostics; we report the mean. The strongest predictors of later PS status were the Children's Global Assessment Scale; delusions of predicting the future or having one's thoughts/actions controlled; and the percent married in one's neighborhood. Random forest followed by ridge regression was most accurate, with a cross-validated area under the curve (AUC) of 0.67. Adjustment of the model including only six variables reached an AUC of 0.70.

Results support the potential application of risk calculators for screening and identification of at-risk community youth in prospective investigations of developmental trajectories of the PS.

Evidence-based theoretical models outlining the pathways to the development of suicidal ideation may inform treatment. The current research draws from the Interpersonal Theory of Suicide (IPT) and the Integrated Motivational-Volitional (IMV) Model of suicidal behaviour and aims to test the interaction between perceived burdensomeness and thwarted belongingness as proposed by the IPT model, and the defeat-entrapment pathway as proposed by the IMV model, in the prediction of suicidal ideation at 12-month follow-up.

The Scottish Wellbeing Study is a nationally representative prospective study of young people aged 18–34 years (n = 3508) from across Scotland, who completed a baseline interview and a 12-month follow-up (n = 2420). The core factors from both the IPT (perceived burdensomeness and thwarted belongingness) and the IMV model (defeat, internal and external entrapment) were measured alongside demographics, depressive symptoms and suicidal ideation at baseline. At 12-month follow-up, suicidal ideation was assessed again.

In multiple regression analysis perceived burdensomeness and internal entrapment, with baseline suicidal ideation, predicted 12-month suicidal ideation. No support for the interaction between perceived burdensomeness and thwarted belongingness in predicting 12-month suicidal ideation was found. However, there was evidence that internal, but not external, entrapment mediated the relationship between defeat and 12-month suicidal ideation, but no support was found for the moderation of burdensomeness and belongingness on the entrapment to suicidal ideation pathway.

The current findings highlight the importance of targeting perceived burdensomeness and internal entrapment to reduce the likelihood that suicidal ideation emerges in at risk individuals.

Drug classes are grouped based on their chemical and pharmacological properties, but prescription and illicit drugs differ in other important ways. Potential differences in genetic and environmental influences on the (mis)use of prescription and illicit drugs that are subsumed under the same class should be examined. Opioid and stimulant classes contain prescription and illicit forms differentially associated with salient risk factors (common route of administration, legality), making them useful comparators for addressing this etiological issue.

A total of 2410 individual Australian twins [Mage = 31.77 (s.d. = 2.48); 67% women] were interviewed about prescription misuse and illicit use of opioids and stimulants. Univariate and bivariate biometric models partitioned variances and covariances into additive genetic, shared environmental, and unique environmental influences across drug types.

Variation in the propensity to misuse prescription opioids was attributable to genes (41%) and unique environment (59%). Illicit opioid use was attributable to shared (71%) and unique (29%) environment. Prescription stimulant misuse was attributable to genes (79%) and unique environment (21%). Illicit stimulant use was attributable to genes (48%), shared environment (29%), and unique environment (23%). There was evidence for genetic influence common to both stimulant types, but limited evidence for genetic influence common to both opioid types. Bivariate correlations suggested that prescription opioid use may be more genetically similar to prescription stimulant use than to illicit opioid use.

Prescription opioid misuse may share little genetic influence with illicit opioid use. Future research may consider avoiding unitary drug classifications, particularly when examining genetic influences.

Genotype-first and within-family studies can elucidate factors that contribute to psychiatric illness. Combining these approaches, we investigated the patterns of influence of parental scores, a high-impact variant, and schizophrenia on dimensional neurobehavioral phenotypes implicated in major psychiatric disorders.

We quantitatively assessed cognitive (FSIQ, VIQ, PIQ), social, and motor functioning in 82 adult individuals with a de novo 22q11.2 deletion (22 with schizophrenia), and 148 of their unaffected parents. We calculated within-family correlations and effect sizes of the 22q11.2 deletion and schizophrenia, and used linear regressions to assess contributions to neurobehavioral measures.

Proband-parent intra-class correlations (ICC) were significant for cognitive measures (e.g. FSIQ ICC = 0.549, p < 0.0001), but not for social or motor measures. Compared to biparental scores, the 22q11.2 deletion conferred significant impairments for all phenotypes assessed (effect sizes −1.39 to −2.07 s.d.), strongest for PIQ. There were further decrements in those with schizophrenia. Regression models explained up to 37.7% of the variance in IQ and indicated that for proband IQ, parental IQ had larger effects than schizophrenia.

This study, for the first time, disentangles the impact of a high-impact variant from the modifying effects of parental scores and schizophrenia on relevant neurobehavioral phenotypes. The robust proband-parent correlations for cognitive measures, independent of the impact of the 22q11.2 deletion and of schizophrenia, suggest that, for certain phenotypes, shared genetic variation plays a significant role in expression. Molecular genetic and predictor studies are needed to elucidate shared factors and their contribution to psychiatric illness in this and other high-risk groups.

Network approach has been applied to a wide variety of psychiatric disorders. The aim of the present study was to identify network structures of remitters and non-remitters in patients with first-episode psychosis (FEP) at baseline and the 6-month follow-up.

Participants (n = 252) from the Korean Early Psychosis Study (KEPS) were enrolled. They were classified as remitters or non-remitters using Andreasen's criteria. We estimated network structure with 10 symptoms (three symptoms from the Positive and Negative Syndrome Scale, one depressive symptom, and six symptoms related to schema and rumination) as nodes using a Gaussian graphical model. Global and local network metrics were compared within and between the networks over time.

Global network metrics did not differ between the remitters and non-remitters at baseline or 6 months. However, the network structure and nodal strengths associated with positive-self and positive-others scores changed significantly in the remitters over time. Unique central symptoms for remitters and non-remitters were cognitive brooding and negative-self, respectively. The correlation stability coefficients for nodal strength were within the acceptable range.

Our findings indicate that network structure and some nodal strengths were more flexible in remitters. Negative-self could be an important target for therapeutic intervention.

The association between suicide attempts (SAs) in parents and children is unclear, and risk indicators for intergenerational transmission remain undocumented. We aimed to assess this association, considering the child's developmental period at the time of parents' attempted suicide, and the parental relation.

Using a prospective cohort design, nationwide population data were linked to the Psychiatric Central Register and National Patient Register for all individuals aged 10 years or older living in Denmark between 1980 and 2016. We assessed incidence rate ratios (IRRs) and cumulative hazards for children's first SA.

In a cohort of 4 419 651 children, 163 056 (3.7%) had experienced a parental SA. An SA was recorded among 6996 (4.3%) of the exposed children as opposed to 70112 (1.6%) in unexposed individuals. Higher rates were noted when a parental SA occurred during early childhood (0 ⩽ age < 2) [IRR, 4.7; 95% confidence interval (CI) 4.2–5.4] v. late childhood (6 ⩽ age < 13) (IRR, 3.6; 95% CI 3.4–3.8) when compared to those unexposed. Children exposed prior to age 2 had the highest rates of all sub-groups when reaching age 13–17 (IRR, 6.5; 95% CI 6.0–7.1) and 18–25 years (IRR, 6.8; 95% CI 6.2–7.4). Maternal SA (IRR, 3.4; 95% CI 3.2–3.5) was associated with higher rates than paternal (IRR, 2.8; 95% CI 2.7–2.9).

Parental SA was associated with children's own SA. Exposure during early developmental stages was associated with the highest rates. Early preventive efforts are warranted as is monitoring of suicide risk in the children from age 13.

Policy in many high-income settings supports giving pregnant women with previous caesarean section a choice between an elective repeat caesarean section (ERCS) or planning a vaginal birth after previous caesarean (VBAC), provided they have no contraindications to VBAC. Despite the potential for this choice to influence women's mental health, evidence about the associated effect to counsel women and identify potential targets for intervention is limited. This study investigated the association between planned mode of birth after previous caesarean and women's subsequent use of psychotropic medications.

A population-based cohort study of 31 131 women with one or more previous caesarean sections who gave birth to a term singleton in Scotland between 2010 and 2015 with no prior psychotropic medications in the year before birth was conducted using linked Scottish national datasets. Cox regression was used to investigate the association between planned mode of birth and being dispensed psychotropic medications in the first year postpartum adjusted for socio-demographic, medical, pregnancy-related factors and breastfeeding.

Planned VBAC (n = 10 220) compared to ERCS (n = 20 911) was associated with a reduced risk of the mother being dispensed any psychotropic medication [adjusted hazard ratio (aHR) 0.85, 95% confidence interval (CI) 0.78–0.92], an antidepressant (aHR 0.83, 95% CI 0.76–0.90), and at least two consecutive antidepressants (aHR 0.83, 95% CI 0.75–0.91) in the first year postpartum.

Women giving birth by ERCS were more likely than those having a planned VBAC to be dispensed psychotropic medication including antidepressants in the first year postpartum. Further research is needed to establish the reasons behind this new finding.

The coronavirus [coronavirus disease 2019 (COVID-19)] pandemic has introduced extraordinary life changes and stress, particularly in adolescents and young adults. Initial reports suggest that depression and anxiety are elevated during COVID-19, but no prior study has explored changes at the within-person level. The current study explored changes in depression and anxiety symptoms from before the pandemic to soon after it first peaked in Spring 2020 in a sample of adolescents and young adults (N = 451) living in Long Island, New York, an early epicenter of COVID-19 in the U.S.

Depression (Children's Depression Inventory) and anxiety symptoms (Screen for Child Anxiety Related Symptoms) were assessed between December 2014 and July 2019, and, along with COVID-19 experiences, symptoms were re-assessed between March 27th and May 15th, 2020.

Across participants and independent of age, there were increased generalized anxiety and social anxiety symptoms. In females, there were also increased depression and panic/somatic symptoms. Multivariable linear regression indicated that greater COVID-19 school concerns were uniquely associated with increased depression symptoms. Greater COVID-19 home confinement concerns were uniquely associated with increased generalized anxiety symptoms, and decreased social anxiety symptoms, respectively.

Adolescents and young adults at an early epicenter of the COVID-19 pandemic in the U.S. experienced increased depression and anxiety symptoms, particularly amongst females. School and home confinement concerns related to the pandemic were independently associated with changes in symptoms. Overall, this report suggests that the COVID-19 pandemic is having multifarious adverse effects on the mental health of youth.

Despite evidence for the general effectiveness of psychological therapies, there exists substantial heterogeneity in patient outcomes. We aimed to identify factors associated with baseline severity of depression and anxiety symptoms, rate of symptomatic change over the course of therapy, and symptomatic recovery in a primary mental health care setting.

Using data from a service evaluation involving 35 527 patients in England's psychological and wellbeing [Improving Access to Psychological Therapies (IAPT)] services, we applied latent growth models to explore which routinely-collected sociodemographic, clinical, and therapeutic variables were associated with baseline symptom severity and rate of symptomatic change. We used a multilevel logit model to determine variables associated with symptomatic recovery.

Being female, younger, more functionally impaired, and more socioeconomically disadvantaged was associated with higher baseline severity of both depression and anxiety symptoms. Being older, less functionally impaired, and having more severe baseline symptomatology was associated with more rapid improvement of both depression and anxiety symptoms (male gender and greater socioeconomic disadvantage were further associated with rate of change for depression only). Therapy intensity and appointment frequency seemed to have no correlation with rate of symptomatic improvement. Patients with lower baseline symptom severity, less functional impairment, and older age had a greater likelihood of achieving symptomatic recovery (as defined by IAPT criteria).

We must continue to investigate how best to tailor psychotherapeutic interventions to fit patients’ needs. Patients who begin therapy with more severe depression and/or anxiety symptoms and poorer functioning merit special attention, as these characteristics may negatively impact recovery.

Whether smoking should be regarded as a risk factor for mental disorders remains unresolved. Prescribed psychotropic drugs can be used as indications for mental disorders. We investigated how smoking was prospectively related to prescription of antipsychotics, mood stabilizers, antidepressants, and anxiolytics.

Information about smoking, including the Fagerström Test for Nicotine Dependence, and relevant confounders, were obtained from the population-based Young in Norway Study (N = 2602), with four data collection waves between 1992 and 2006. These survey data were linked with information on prescriptions for psychotropic drugs from the comprehensive, nationwide Norwegian Prescription Database from 2007 to 2015.

Daily smoking with high dependence in 2006 at age 28.5 (s.d. = 2.0) was associated with filling prescriptions of antipsychotics (OR, 6.57, 95% CI 2.19–19.70, p = 0.001), mood stabilizers (OR, 7.11, 95% CI 2.51–20.15, p < 0.001) and antidepressants (OR, 1.91, 95% CI 1.13–3.23, p = 0.016) 1–9 years later. Associations remained significant after adjustment for a variety of potential confounders measured before the assessment of smoking, including sociodemographic background, conduct problems, cannabis use, mental distress, and previous prescriptions for psychotropic medications. The association between smoking and prescription of anxiolytics was weaker and more unstable.

In this study of young adults, daily smoking with high dependence was associated with later prescriptions of antipsychotics, mood stabilizers and antidepressants, indicating smoking as a risk factor for mental disorders treated with these drugs.

The hyper-function of the striatal dopamine system has been suggested to underlie key pathophysiological mechanisms in schizophrenia. Moreover, patients have been observed to present a significant elevation of dopamine receptor availability compared to healthy controls. Although it is difficult to measure dopamine levels directly in humans, neurochemical imaging techniques such as single-photon emission computed tomography (SPECT) provide indirect indices of in vivo dopamine synthesis and release, and putative synaptic levels.

We focused on the role of dopamine postsynaptic regulation using [123I] iodobenzamide (IBZM) SPECT. We compared D2/3 receptor availability between 53 healthy controls and 21 medication-naive patients with recent-onset schizophrenia.

The mean specific striatal binding showed no significant difference between patients and controls (estimated difference = 0.001; 95% CI −0.11 to 0.11; F = 0.00, df = 1, 69; p = 0.99). There was a highly significant effect of age whereby IBZM binding declined with advancing age [estimated change per decade of age = −0.01(binding ratio); 95% CI −0.01 to −0.004; F = 11.5, df = 1, 69; p = 0.001]. No significant correlations were found between the mean specific striatal binding and psychopathological or cognitive rating scores.

Medication-naïve patients with recent-onset schizophrenia have similar D2/3 receptor availability to healthy controls. We suggest that, rather than focusing exclusively on postsynaptic receptors, future treatments should target the presynaptic control of dopamine synthesis and release.

It has been suggested that individual differences in temperament could be involved in the (non-)response to antidepressant (AD) treatment. However, how neurobiological processes such as brain glucose metabolism may relate to personality features in the treatment-resistant depressed (TRD) state remains largely unclear.

To examine how brainstem metabolism in the TRD state may predict Cloninger's temperament dimensions Harm Avoidance (HA), Novelty Seeking (NS), and Reward Dependence (RD), we collected 18fluorodeoxyglucose positron emission tomography (18FDG PET) scans in 40 AD-free TRD patients. All participants were assessed with the Temperament and Character Inventory (TCI). We applied a multiple kernel learning (MKL) regression to predict the HA, NS, and RD from brainstem metabolic activity, the origin of respectively serotonergic, dopaminergic, and noradrenergic neurotransmitter (NT) systems.

The MKL model was able to significantly predict RD but not HA and NS from the brainstem metabolic activity. The MKL pattern regression model identified increased metabolic activity in the pontine nuclei and locus coeruleus, the medial reticular formation, the dorsal/median raphe, and the ventral tegmental area that contributed to the predictions of RD.

The MKL algorithm identified a likely metabolic marker in the brainstem for RD in major depression. Although 18FDG PET does not investigate specific NT systems, the predictive value of brainstem glucose metabolism on RD scores however indicates that this temperament dimension in the TRD state could be mediated by different monoaminergic systems, all involved in higher order reward-related behavior.