Effect of serum concentrations of IL-6 and TNF-α on brain structure in anorexia nervosa: a combined cross-sectional and longitudinal study.

Previous studies of brain structure in anorexia nervosa (AN) have reported reduced gray matter in underweight patients, which largely normalizes upon weight gain. One underlying biological mechanism may be glial cell alterations related to low-grade inflammation. Here, we investigated relationships between brain structure as measured by magnetic resonance imaging and serum concentrations of two pro-inflammatory cytokines (interleukin-6 and tumor necrosis factor alpha) cross-sectionally in 82 underweight adolescent and young adult female patients (mean age 16.8 years; 59 of whom were observed longitudinally after short-term weight restoration; mean duration 2.8 months), 20 individuals long-term weight-recovered from AN (mean age 22.7 years) and 105 healthy control (HC) participants (mean age 17.2 years). We measured cortical thickness, subcortical volumes and local gyrification index, a measure of cortical folding. In contrast to most previous studies of cytokine concentrations in AN, we found no cross-sectional group differences (interleukin-6: p = 0.193, tumor necrosis factor alpha: p = 0.057) or longitudinal changes following weight restoration (interleukin-6: p = 0.201, tumor necrosis factor alpha: p = 0.772). As expected, widespread gray matter reductions (cortical thickness, subcortical volumes, cortical folding) were observed in underweight patients with AN compared to HC. However, we found no evidence of associations between cytokine concentrations and structural brain measures in any participant group. Furthermore, longitudinal changes in cytokine concentrations were unrelated to changes in gray matter. In conclusion, we did not identify any association between (sub-)inflammatory processes and structural brain changes in AN. Future studies are needed to elucidate which other factors besides nutritional status may contribute to brain morphological alterations.

Longitudinal changes in brain-derived neurotrophic factor (BDNF) but not cytokines contribute to hippocampal recovery in anorexia nervosa above increases in body mass index.

BACKGROUND: Physical sequelae of anorexia nervosa (AN) include a marked reduction in whole brain volume and subcortical structures such as the hippocampus. Previous research has indicated aberrant levels of inflammatory markers and growth factors in AN, which in other populations have been shown to influence hippocampal integrity. METHODS: Here we investigated the influence of concentrations of two pro-inflammatory cytokines (tumor necrosis factor-alpha [TNF-α] and interleukin-6 [IL-6]) and brain-derived neurotrophic factor (BDNF) on the whole hippocampal volume, as well as the volumes of three regions (the hippocampal body, head, and tail) and 18 subfields bilaterally. Investigations occurred both cross-sectionally between acutely underweight adolescent/young adult females with AN (acAN; n = 82) and people recovered from AN (recAN; n = 20), each independently pairwise age-matched with healthy controls (HC), and longitudinally in acAN after partial renourishment (n = 58). Hippocampal subfield volumes were quantified using FreeSurfer. Concentrations of molecular factors were analyzed in linear models with hippocampal (subfield) volumes as the dependent variable. RESULTS: Cross-sectionally, there was no evidence for an association between IL-6, TNF-α, or BDNF and between-group differences in hippocampal subfield volumes. Longitudinally, increasing concentrations of BDNF were positively associated with longitudinal increases in bilateral global hippocampal volumes after controlling for age, age2, estimated total intracranial volume, and increases in body mass index (BMI). CONCLUSIONS: These findings suggest that increases in BDNF may contribute to global hippocampal recovery over and above increases in BMI during renourishment. Investigations into treatments targeted toward increasing BDNF in AN may be warranted.

Study protocol: the pragmatic, exploratory DELTA-JU trial of the group-based multimodal DELTA intervention for abstinent adolescents with substance use disorders living in youth welfare institutions.

Background: The DELTA intervention contains 16 weekly group sessions plus additional individual sessions and educational session for parents. It aims to reduce substance use and related problems such as substance use disorders (SUD) in adolescents. Recent results indicated positive effects in psychiatric outpatients. Conducting DELTA in youth welfare settings seems feasible, however, organizational and content adjustments such as smoking cessation elements should be added in order to reduce relapse risks and to prevent negative health consequences. Methods/design: The pre-registered DELTA-JU study (German Clinical Trials Register, DRKS00027913) is separated into three stages: In the adjustment stage during months 1-4, we will revise the DELTA manual based on semi-structured interviews (n = 10) with personnel from youth welfare institutions specialized in serving adolescents with SUD in the study region, analyzed with content analysis. In the sampling stage during months 5-22, participants qualifying for a SUD and willing to regularly participate in the 16 weekly DELTA-JU group sessions will be enrolled to either one of two arms (cluster randomization: immediate intervention, waitlist with subsequent intervention 16 weeks later). Adolescents will be assessed at baseline and follow-up (16 weeks after first group session) with an additional pre-assessment (16 weeks before intervention starts) for the waitlist group. Assessment procedures include questionnaires and clinical interviews among others. At the same time, institutional personnel will receive a 1-day workshop on SUD-relevant topics based on the DELTA parental education group and on feedback from the qualitative interviews. Personnel will also be assessed twice with questionnaires. In the dissemination stage during months 23-24, final study evaluation results will be prepared and submitted for publication. Discussion: This study will create a setting-specific manual for vulnerable adolescents suffering from SUDs, and, in many cases, from co-occurring mental disorders. If shown to be effective, DELTA-JU can be disseminated within other institutions of youth welfare.

Attenuated psychotic symptoms, substance use and self-reported PTSD in adolescence.

Background: The occurrence of attenuated psychotic symptoms (APS) is a major concern in populations with substance use disorders (SUDs). However, APS also frequently develop in the course of Post-Traumatic Stress Disorder (PTSD). This study explores how the prevalence of APS differs between adolescent patients with only SUD, SUD with a history of traumatic experiences (TEs), and with SUD and self-reported PTSD.Methods: We recruited n = 120 treatment-seeking adolescents at a German outpatient clinic for adolescents with SUD. All participants filled out questionnaires assessing APS (PQ-16, YSR schizoid scale), trauma history, PTSD symptoms (both UCLA PTSD Index), and SUD severity (DUDIT) next to an extensive substance use interview. We performed a multivariate analysis of co-variance with the four PQ-16 scales and the YSR scale as outcomes and PTSD status as predictor. Additionally, we performed five linear regressions predicting each PQ-16 score and YSR score based on tobacco, alcohol, cannabis, ecstasy, amphetamine, and methamphetamine use.Results: Participants with co-occurring SUD and self-reported PTSD showed significantly higher APS prevalence rates (PQ-16 score, p = .00002), more disturbed thought content (p = .000004), more perceptual disturbances (p = .002), more negative symptoms (p = .004) and more thought problems (p = .001) compared to adolescents with SUD and a history of trauma and adolescents with only SUD. Past-year substance use was not predictive for APS prevalence (F(75) = 0.42; p = .86; R2 = .04).Conclusion: Our data suggests that the occurrence of APS in adolescents with SUD is better explained by co-occurring self-reported PTSD than by substance use frequency or substance class. This finding might indicate that APS might be reduced through treating PTSD or focusing on TEs in SUD therapy.

Adolescents with co-occurring substance use disorders and PTSD show increased rates of Attenuated Psychotic Symptoms (APS).A history of traumatic experiences and PTSD are stronger predictors for APS than substance use.APS in adolescents with substance use disorders may be an indication of undiagnosed and/or untreated co-occurring PTSD.

[Non-smoker protection and tobacco cessation]. / Nichtraucherschutz und Tabakentwöhnung.

Non-smoker protection and tobacco cessation Abstract. Objective: Whereas, on the one hand, employees in child and adolescent psychiatric institutions (CAP) have to enforce smoking bans among patients, on the other hand, they have a high likelihood of being smokers themselves. Little data are available on the enforcement of smoking regulations and what cessation support is offered by CAP institutions. Method: In an online survey, n = 78 senior staff members or directors of German CAP institutions (41.9 % of all addressed CAP institutions) responded to questions on smoking regulations, exceptions, and cessation support for employees. Results: The enforcement of comprehensive smoking bans is rarely reported (<20 % of CAP institutions). Employees are exempted or allowed to smoke mostly outside of the building (e. g., in designated smoking areas: 69-78 % depending on ward type). Cessation support was offered by less than half of the CAP institutions (47%). Conclusions: The data presented point toward future areas for tobacco control in CAP care, including transparent regulations, staff training, and dissemination of support for occupational smoking cessation.

Editorial Perspective: Medical body modification in youth with gender dysphoria or body dysmorphic disorder - is current practice coherent and evidence-based?

In recent decades, there has been a steady increase in the number of people, including adolescents, undergoing medical body modification (MBM) to alter their physically healthy bodies in invasive and nearly irreversible ways through medical treatment (e.g. surgery). While MBM is often recommended for youth with persisting gender dysphoria (GD), in body dysmorphic disorder (BDD) it has been considered contraindicated. Here, we outline the current controversies surrounding MBM practice and recommendations in adolescents with GD versus those with BDD in order to better understand under what circumstances we may or may not support adolescents who want to change their bodies medically and often irreversibly. We compare the two disorders in terms of the overlap and uniqueness of their behavioural and psychological features. In doing so, we discuss limitations of the existing (often low-quality) evidence for and against MBM in young patients. We conclude that the currently available evidence is too preliminary and far from conclusive to make any robust recommendations in terms of benefits and harms of MBM in youth with persisting GD or BDD. However, we strongly recommend further urgent scientific discussions and systematic research efforts into more robust evaluations and the identification of more precise psychological characteristics that may serve as decision criteria for or against MBM - particularly in those adolescents who did not respond to non-MBM, that is, psychiatric/psychological treatment and psychosocial support, if available at all. This will greatly benefit youth healthcare professionals in their challenging clinical practice of making decisions regarding MBM today and in the future.

[Implementation of Tobacco Control Strategies in Psychiatric Institutions for Children and Adolescents: an Online Survey of Leading Staff Members]. / Umsetzung von Tabakkontrollmaßnahmen in Einrichtungen der Kinder- und Jugendpsychiatrie: Eine Online-Befragung von leitenden Mitarbeitenden.

OBJECTIVE: Tobacco control measures are relevant also in child and adolescent psychiatric institutions and their implementation in Germany will be assessed in this study. METHODS: In an online survey, n=78 leading staff members responded to standardized questions assessing how smoking in patients was dealt in such institutions. RESULTS: The majority of institutions (70-87%) had smoking bans in the psychiatric clinic buildings and premises. Depending on the type of psychiatric ward, exceptions were in place in the form of a designated smoking area (38%), smoking pavilion (19%), or when patients suffered from certain mental disorders (28%). Documentation of violations of the ban varied with the type of ward (30-79%), while in most cases violations led to consequences (84-93%) including confiscation of smoking utilities (42-63%) or a curfew (25-38%). Smoking cessation aids were reported by 78% of the institutions, most often as consultations (64%). Pharmacological treatments for smoking were provided in inpatient wards (71-83%). One in two institutions documented the result of cessation attempts (54%). Smoking-related working groups (14%) or the use of standardized diagnostic instruments (0-4%) were much less frequently reported. DISCUSSION: We provide a first look at tobacco control policy measures in child and adolescent psychiatric institutions on a national scale. This allows us to derive future areas for tobacco control.

Coping motives mediate the relationship between PTSD and MDMA use in adolescents with substance use disorders.

BACKGROUND: Post-traumatic stress disorder (PTSD) and substance use disorders (SUDs) often co-occur in adolescent patients. Previous research has shown that these patients differ from SUD patients without PTSD in terms of their substance use patterns. In this study, we aimed to test whether substance use in this population is related to an attempt to self-medicate PTSD-related symptoms. METHODS: German adolescent patients (aged 13-18 years) at an outpatient clinic for SUD treatment, n = 111 (43% female), completed a self-designed questionnaire on use motives, a measure of PTSD-related experiences, and underwent a standardized psychiatric interview including structured substance use questions. Participants were subsequently classified as 'no traumatic experiences ('noTEs' but SUD), 'traumatic experiences but no current PTSD diagnosis' ('TEs' with SUD), and 'PTSD' with SUD. After establishing a self-designed motive measurement through exploratory and confirmatory factor analyses, we calculated non-parametric group differences and a mediation analysis in a linear regression framework. RESULTS: The past-year frequency of MDMA use was highest in the PTSD group and lowest in the noTE group (H (2) = 7.2, p = .027, η2 = .058), but no differences were found for frequencies of tobacco, alcohol, cannabis, or stimulant use (all H ≤ 4.9, p ≥ .085, η2 ≤ .033). While controlling for sex, the three groups showed a similar pattern (highest in the PTSD group and lowest in the noTE group) for coping scores (F (103) = 5.77, p = .004, η2 = .101). Finally, mediation analyses revealed an indirect effect of coping score (b = 0.61, 95% CI [0.29, 1.58], p = .145) on the association between group membership and MDMA use frequency. CONCLUSIONS: In adolescent SUD patients, we found an association of current PTSD and lifetime traumatic experiences with higher MDMA use that could be partially explained by substance use being motivated by an attempt to cope with mental health symptoms. This indicates a coping process involved specifically in MDMA use compared to the use of other psychoactive substances, possibly due to unique psychoactive effects of MDMA.

Anxiety Is Associated With DPPIV Alterations in Children With Selective Mutism and Social Anxiety Disorder: A Pilot Study.

Background: Both selective mutism (SM) and social anxiety disorder (SAD) are severe pediatric anxiety disorders with the common trait of behavioral inhibition (BI). The underlying pathophysiology of these disorders remains poorly understood, however converging evidence suggests that alterations in several peripheral molecular pathways might be involved. In a pilot study, we investigated alterations in plasma molecular markers (dipeptidyl peptidase-4 [DPPIV], interleukin-6 [IL-6], tumor necrosis factor-ß [TNF-ß] and neuropeptide-Y [NPY]) in children with SM, SAD, and healthy controls, as well as the correlation of these markers to symptom severity. Methods: We included 51 children and adolescents (aged 5-18 years; n = 29 girls): n = 20 children in the SM-, n = 16 in the SAD- and n = 15 in the control-group (CG). Peripheral blood samples were analyzed for DPPIV, IL-6, TNF-ß, and NPY concentrations. Diverse psychometric measures were used for BI, anxiety, and mutism symptoms. Results: Lower DPPIV-levels were correlated with more anxiety symptoms. However, we could not find a difference in any molecular marker between the patients with SAD and SM in comparison to the CG. Conclusion: DPPIV is proposed as relevant marker for child and adolescent anxiety. Investigating the pathophysiology of SM and SAD focusing on state and trait variables as anxiety or BI might help better understanding the underlying mechanisms of these disorders. Further studies with especially larger cohorts are needed to validate the current pilot-findings.

Is Serum BDNF Altered in Acute, Short- and Long-Term Recovered Restrictive Type Anorexia Nervosa?

Brain-derived neurotrophic factor (BDNF), a neurotrophin involved in the regulation of food intake and body weight, has been implicated in the development and maintenance of Anorexia nervosa (AN). The majority of previous studies reported lower BDNF levels in acutely underweight AN patients (acAN) and increasing levels after weight rehabilitation. Here, we investigated serum BDNF concentrations in the largest known AN sample to date, both before and after weight restoration therapy. Serum BDNF was measured in 259 female volunteers: 77 in-patient acAN participants of the restrictive type (47 reassessed after short-term weight rehabilitation), 62 individuals long-term recovered from AN, and 120 healthy controls. We validated our findings in a post-hoc mega-analysis in which we reanalyzed combined data from the current sample and those from our previous study on BDNF in AN (combined sample: 389 participants). All analyses carefully accounted for known determinants of BDNF (age, sex, storage time of blood samples). We further assessed relationships with relevant clinical variables (body-mass-index, physical activity, symptoms). Contrary to our hypotheses, we found zero significant differences in either cross-sectional or longitudinal comparisons and no significant relationships with clinical variables. Together, our study suggests that BDNF may not be a reliable state- or trait-marker in AN after all.

[Substance Use, Resulting Disorders, and Collateral Mental Disorders Among Adolescents in a Special Outpatient Institutions for Addictions]. / Substanzkonsum, Störungen durch Substanzkonsum und begleitende psychische Störungen bei Jugendlichen.

Substance Use, Resulting Disorders, and Collateral Mental Disorders Among Adolescents in a Special Outpatient Institutions for Addictions Abstract. Objective: Only few clinics offer the outpatient treatment of substance use disorders (SUDs) among adolescents. Therefore, only limited data describe substance use patterns, SUDs, and co-occurring psychiatric disorders characteristic of adolescents who present in such outpatient clinics specialized in the treatment of SUDs. Method: Via interview we collected data from n = 201 patients between 12 and 19 years concerning their substance use, SUDs, and current co-occurring psychiatric disorders. We created descriptive presentation of data regarding use patterns, SUDs, and co-occurring disorders divided by sex and current age. Results: Tobacco (88 %) and cannabis (86 %) were the most frequently used substances. 67 % of all patients presented with more than one SUD, cannabis use disorder being the most prevalent one (84 %). 72 % presented with at least one co-occurring disorder, with conduct disorders (40 %), attention deficit (hyperactivity) disorders (21 %), and depressive disorders (18 %) being the most frequent ones. Conclusions: Adolescent SUD patients often present with co-occurring psychiatric disorders. Institutions for adolescent SUD treatment should also focus on treating co-occurring conduct disorders, depression, and attention deficit disorders.

Beyond the tip of the iceberg: A narrative review to identify research gaps on comorbid psychiatric disorders in adolescents with methamphetamine use disorder or chronic methamphetamine use.

BACKGROUND: Methamphetamine use disorder (MUD) frequently begins in adolescence, often accompanied by other psychiatric or mental disorders. Up to now, no comprehensive review about MUD and comorbid disorders in adolescents is available. We thus aimed to review the literature on comorbid mental disorders and MUD in adolescents in order to identify future research topics. Method: A PubMed search was conducted in July 2019. Relevant comorbidities were defined as attention-deficit disorder with/without hyperactivity, anxiety disorders, depression, eating disorders, post-traumatic stress disorder, psychosis, borderline personality disorder, conduct disorder and antisocial personality disorder, as well as other substance use disorders. For each comorbidity, we summarized prevalence rates, findings on comorbidity mechanisms, and recommended treatment options, if applicable. Results: Few articles focused on MUD in adolescents. Prevalence rates differed largely between comorbid disorders, with tobacco use disorder, conduct disorder, post-traumatic stress disorder, anxiety disorders, and attention-deficit disorders being the most prevalent comorbidities while eating disorders were rare. Examined onset patterns and comorbidity mechanisms indicated three groups of comorbidities: preexisting disorders self-medicated with methamphetamine, disorders induced by chronic methamphetamine use, and disorders arising due to risk factors shared with MUD. Reviewed comorbidities were frequently associated with worse treatment outcomes. Conclusions: The limited evidence is in stark contrast to the presumably high prevalence and relevance of comorbid mental disorders in adolescents with MUD. Suggestions for future research topics, informed by adult findings, include genetic vulnerabilities, biological changes, and consequences of different use patterns. Surprisingly few MUD treatment programs explicitly integrate comorbid mental disorder modules.

[Neuropsychiatric manifestations in Tuberous Sclerosis Complex (TSC): diagnostic guidelines, TAND concept and therapy with mTOR inhibitors]. / Neuropsychiatrische Manifestationen bei Tuberöser Sklerose (TSC): Diagnostische Leitlinien, TAND-Konzept und Therapie mit mTOR-Inhibitoren.

Neuropsychiatric manifestations in Tuberous Sclerosis Complex (TSC): diagnostic guidelines, TAND concept and therapy with mTOR inhibitors Abstract. Tuberous sclerosis complex (TSC), albeit a rare autosomal-dominant multisystem disease with an incidence of 1:6,000, is one of the most important monogenetic disorders in child and adolescent psychiatry. In up to 90 % of patients, neurological disorders such as epilepsy and psychiatric disorders such as autism spectrum disorder, ADHD, affective disorders, and intellectual disability are observed. In recent years, significant progress has been made in understanding the molecular mechanism as well as in the clinical diagnosis and treatment of the disease. Here, we review these recent developments. In the first part, we describe the need for psychiatric assessment and treatment of patients and analyse challenges in interdisciplinary work between child and adolescent psychiatry, child neurology, and other professional groups. In the second part, we introduce the concept of TSC-associated neuropsychiatric disorders (TAND), developed by the TSC Neuropsychiatry Panel as a guide to help clinical teams, families, and individuals with TSC via screening, assessment, and treatment of neuropsychiatric symptoms and disorders as well as with a novel screening instrument, the TAND Checklist. Finally, we report findings from recent clinical trials of mTOR-inhibitors to treat TAND. The paper includes the German translation of the TAND Checklist as an electronic supplement.

Conflict processing in juvenile patients with neurofibromatosis type 1 (NF1) and healthy controls - Two pathways to success.

Neurofibromatosis Type 1 (NF1) is a monogenetic autosomal-dominant disorder with a broad spectrum of clinical symptoms and is commonly associated with cognitive deficits. Patients with NF1 frequently exhibit cognitive impairments like attention problems, working memory deficits and dysfunctional inhibitory control. The latter is also relevant for the resolution of cognitive conflicts. However, it is unclear how conflict monitoring processes are modulated in NF1. To examine this question in more detail, we used a system neurophysiological approach combining high-density ERP recordings with source localisation analyses in juvenile patients with NF1 and controls during a flanker task. Behaviourally, patients with NF1 perform significantly slower than controls. Specifically on trials with incompatible flanker-target pairings, however, the patients with NF1 made significantly fewer errors than healthy controls. Yet, importantly, this overall successful conflict resolution was reached via two different routes in the two groups. The healthy controls seem to arrive at a successful conflict monitoring performance through a developing conflict recognition via the N2 accompanied by a selectively enhanced N450 activation in the case of perceived flanker-target conflicts. The presumed dopamine deficiency in the patients with NF1 seems to result in a reduced ability to process conflicts via the N2. However, NF1 patients show an increased N450 irrespective of cognitive conflict. Activation differences in the orbitofrontal cortex (BA11) and anterior cingulate cortex (BA24) underlie these modulations. Taken together, juvenile patients with NF1 and juvenile healthy controls seem to accomplish conflict monitoring via two different cognitive neurophysiological pathways.

Response inhibition in Attention deficit disorder and neurofibromatosis type 1 - clinically similar, neurophysiologically different.

There are large overlaps in cognitive deficits occurring in attention deficit disorder (ADD) and neurodevelopmental disorders like neurofibromatosis type 1 (NF1). This overlap is mostly based on clinical measures and not on in-depth analyses of neuronal mechanisms. However, the consideration of such neuronal underpinnings is crucial when aiming to integrate measures that can lead to a better understanding of the underlying mechanisms. Inhibitory control deficits, for example, are a hallmark in ADD, but it is unclear how far there are similar deficits in NF1. We thus compared adolescent ADD and NF1 patients to healthy controls in a Go/Nogo task using behavioural and neurophysiological measures. Clinical measures of ADD-symptoms were not different between ADD and NF1. Only patients with ADD showed increased Nogo errors and reductions in components reflecting response inhibition (i.e. Nogo-P3). Early perceptual processes (P1) were changed in ADD and NF1. Clinically, patients with ADD and NF1 thus show strong similarities. This is not the case in regard to underlying cognitive control processes. This shows that in-depth analyses of neurophysiological processes are needed to determine whether the overlap between ADD and NF1 is as strong as assumed and to develop appropriate treatment strategies.

Correspondence of DNA Methylation Between Blood and Brain Tissue and Its Application to Schizophrenia Research.

Given the difficulty of procuring human brain tissue, a key question in molecular psychiatry concerns the extent to which epigenetic signatures measured in more accessible tissues such as blood can serve as a surrogate marker for the brain. Here, we aimed (1) to investigate the blood-brain correspondence of DNA methylation using a within-subject design and (2) to identify changes in DNA methylation of brain-related biological pathways in schizophrenia.We obtained paired blood and temporal lobe biopsy samples simultaneously from 12 epilepsy patients during neurosurgical treatment. Using the Infinium 450K methylation array we calculated similarity of blood and brain DNA methylation for each individual separately. We applied our findings by performing gene set enrichment analyses (GSEA) of peripheral blood DNA methylation data (Infinium 27K) of 111 schizophrenia patients and 122 healthy controls and included only Cytosine-phosphate-Guanine (CpG) sites that were significantly correlated across tissues.Only 7.9% of CpG sites showed a statistically significant, large correlation between blood and brain tissue, a proportion that although small was significantly greater than predicted by chance. GSEA analysis of schizophrenia data revealed altered methylation profiles in pathways related to precursor metabolites and signaling peptides.Our findings indicate that most DNA methylation markers in peripheral blood do not reliably predict brain DNA methylation status. However, a subset of peripheral data may proxy methylation status of brain tissue. Restricting the analysis to these markers can identify meaningful epigenetic differences in schizophrenia and potentially other brain disorders.

Smoking status as a potential confounder in the study of brain structure in schizophrenia.

Several but not all MRI studies have reported volume reductions in the hippocampus and dorsolateral prefrontal cortex (DLPFC) in patients with schizophrenia. Given the high prevalence of smoking among schizophrenia patients and the fact that smoking has also been associated with alterations in brain morphology, this study evaluated whether a proportion of the known gray matter reductions in key brain regions may be attributed to smoking rather than to schizophrenia alone. We examined structural MRI data of 112 schizophrenia patients (53 smokers and 59 non-smokers) and 77 healthy non-smoker controls collected by the MCIC study of schizophrenia. An automated atlas based probabilistic method was used to generate volumetric measures of the hippocampus and DLPFC. The two patient groups were matched with respect to demographic and clinical variables. Smoker schizophrenia patients showed significantly lower hippocampal and DLPFC volumes than non-smoker schizophrenia patients. Gray matter volume reductions associated with smoking status ranged between 2.2% and 2.8%. Furthermore, we found significant volume differences between smoker patients and healthy controls in the hippocampus and DLPFC, but not between non-smoker patients and healthy controls. Our data suggest that a proportion of the volume reduction seen in the hippocampus and DLPFC in schizophrenia is associated with smoking rather than with the diagnosis of schizophrenia. These results may have important implications for brain imaging studies comparing schizophrenia patients and other groups with a lower smoking prevalence.