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Experience Sampling Methodology (ESM) is ideally suited to test the predictions, and inform the development of contemporary cognitive models of depression. Yet there has been no systematic examination of ESM in depression research.
Method
A search of databases (PsychARTICLES, PsycINFO, AMED, Ovid Medline and CINAHL) was conducted to identify studies published within the last 25 years investigating major depressive disorder (MDD) using ESM.
Results
Altogether, 19 studies using ESM, or comparable methodologies, with clinically depressed individuals were identified and critically reviewed. The identified studies examined six aspects of MDD: methodological issues; positive and negative affect; cortisol secretion; antidepressant treatment; work performance; genetic risk factors.
Conclusions
Despite some methodological limitations of existing studies, ESM has made a significant contribution to our current understanding of depression by consolidating existing theories, uncovering new and clinically relevant findings and identifying questions for future research. This review concludes by introducing the possibility of using ESM as an intervention tool in clinical practice and proposing that ESM could be useful for furthering knowledge of the causes of MDD.
Major depressive disorder (MDD) is commonly chronic and/or recurrent. We aimed to determine whether a chronic and/or recurrent course of MDD is associated with acute and longer-term MDD treatment outcomes.
Method
This cohort study recruited out-patients aged 18–75 years with non-psychotic MDD from 18 primary and 23 psychiatric care clinics across the USA. Participants were grouped as: chronic (index episode >2 years) and recurrent (n=398); chronic non-recurrent (n=257); non-chronic recurrent (n=1614); and non-chronic non-recurrent (n=387). Acute treatment was up to 14 weeks of citalopram (⩽60 mg/day) with up to 12 months of follow-up treatment. The primary outcomes for this report were remission [16-item Quick Inventory of Depressive Symptomatology – Self-Rated (QIDS-SR16) ⩽5] or response (⩾50% reduction from baseline in QIDS-SR16) and time to first relapse [first QIDS-SR16 by Interactive Voice Response (IVR) ⩾11].
Results
Most participants (85%) had a chronic and/or recurrent course; 15% had both. Chronic index episode was associated with greater sociodemographic disadvantage. Recurrent course was associated with earlier age of onset and greater family histories of depression and substance abuse. Remission rates were lowest and slowest for those with chronic index episodes. For participants in remission entering follow-up, relapse was most likely for the chronic and recurrent group, and least likely for the non-chronic, non-recurrent group. For participants not in remission when entering follow-up, prior course was unrelated to relapse.
Conclusions
Recurrent MDD is the norm for out-patients, of whom 15% also have a chronic index episode. Chronic and recurrent course of MDD may be useful in predicting acute and long-term MDD treatment outcomes.
Understanding individual differences in susceptibility to antidepressant therapy side-effects is essential to optimize the treatment of depression.
Method
We performed genome-wide association studies (GWAS) to search for genetic variation affecting the susceptibility to side-effects. The analysis sample consisted of 1439 depression patients, successfully genotyped for 421K single nucleotide polymorphisms (SNPs), from the Sequenced Treatment Alternatives to Relieve Depression (STAR*D) study. Outcomes included four indicators of side-effects: general side-effect burden, sexual side-effects, dizziness and vision/hearing-related side-effects. Our criterion for genome-wide significance was a prespecified threshold ensuring that, on average, only 10% of the significant findings are false discoveries.
Results
Thirty-four SNPs satisfied this criterion. The top finding indicated that 10 SNPs in SACM1L mediated the effects of bupropion on sexual side-effects (p=4.98×10−7, q=0.023). Suggestive findings were also found for SNPs in MAGI2, DTWD1, WDFY4 and CHL1.
Conclusions
Although our findings require replication and functional validation, this study demonstrates the potential of GWAS to discover genes and pathways that could mediate adverse effects of antidepressant medication.
Although there is substantial evidence for the efficacy of life review therapy as an early treatment of depression in later life, its effectiveness in natural settings has not been studied. The present study evaluates an intervention based on life review and narrative therapy in a large multi-site, pragmatic randomized controlled trial (RCT).
Method
Life review therapy was compared with care as usual. The primary outcome was depressive symptoms; secondary outcomes were anxiety symptoms, positive mental health, quality of life, and current major depressive episode (MDE). To identify groups for whom the intervention was particularly effective, moderator analyses were carried out (on sociodemographic variables, personality traits, reminiscence functions, clinically relevant depressive and anxiety symptoms, and past MDEs).
Results
Compared with care as usual (n=102), life review therapy (n=100) was effective in reducing depressive symptoms, at post-treatment (d=0.60, B=−5.3, p<0.001), at 3-month follow-up (d=0.50, B=−5.0, p<0.001) and for the intervention also at 9-month follow-up (t=5.7, p<0.001). The likelihood of a clinically significant change in depressive symptoms was significantly higher [odds ratio (OR) 3.77, p<0.001 at post-treatment; OR 3.76, p<0.001 at the 3-month follow-up]. Small significant effects were found for symptoms of anxiety and positive mental health. Moderator analyses showed only two significant moderators, the personality trait of extraversion and the reminiscence function of boredom reduction.
Conclusions
This study shows the effectiveness of life review therapy as an early intervention for depression in an ecologically valid context, supporting its applicability to a broad target group. The intervention is also effective in reducing anxiety symptoms and strengthening positive mental health.
Suicide is the 11th leading cause of death in the USA. Suicide rates vary across ethnic groups. Whether suicide behavior differs by ethnic groups in the USA in the same way as observed for suicide death is a matter of current discussion. The aim of this report was to compare the lifetime prevalence of suicide ideation and attempt among four main ethnic groups (Asians, Blacks, Hispanics, and Whites) in the USA.
Method
Suicide ideation and attempts were assessed using the World Mental Health version of the Composite International Diagnostic Interview (WMH-CIDI). Discrete time survival analysis was used to examine risk for lifetime suicidality by ethnicity and immigration among 15 180 participants in the Collaborative Psychiatric Epidemiological Surveys (CPES), a group of cross-sectional surveys.
Results
Suicide ideation was most common among Non-Hispanic Whites (16.10%), least common among Asians (9.02%) and intermediate among Hispanics (11.35%) and Non-Hispanic Blacks (11.82%). Suicide attempts were equally common among Non-Hispanic Whites (4.69%), Hispanics (5.11%) and Non-Hispanic Blacks (4.15%) and less common among Asians (2.55%). These differences in the crude prevalence rates of suicide ideation decreased but persisted after control for psychiatric disorders, but disappeared for suicide attempt. Within ethnic groups, risk for suicidality was low among immigrants prior to migration compared to the US born, but equalized over time after migration.
Conclusions
Ethnic differences in suicidal behaviors are explained partly by differences in psychiatric disorders and low risk prior to arrival in the USA. These differences are likely to decrease as the US-born proportion of Hispanics and Asians increases.
Cognitive therapy has been found to be effective in decreasing the recurrence of suicide attempts. A theoretical aim of cognitive therapy is to improve problem-solving skills so that suicide no longer remains the only available option. This study examined the differential rate of change in problem-solving appraisal following suicide attempts among individuals who participated in a randomized controlled trial for the prevention of suicide.
Method
Changes in problem-solving appraisal from pre- to 6-months post-treatment in individuals with a recent suicide attempt, randomized to either cognitive therapy (n=60) or a control condition (n=60), were assessed by using the Social Problem-Solving Inventory-Revised, Short Form.
Results
Improvements in problem-solving appraisal were similarly observed for both groups within the 6-month follow-up. However, during this period, individuals assigned to the cognitive therapy condition demonstrated a significantly faster rate of improvement in negative problem orientation and impulsivity/carelessness. More specifically, individuals receiving cognitive therapy were significantly less likely to report a negative view toward life problems and impulsive/carelessness problem-solving style.
Conclusions
Cognitive therapy for the prevention of suicide provides rapid changes within 6 months on negative problem orientation and impulsivity/carelessness problem-solving style. Given that individuals are at the greatest risk for suicide within 6 months of their last suicide attempt, the current study demonstrates that a brief cognitive intervention produces a rapid rate of improvement in two important domains of problem-solving appraisal during this sensitive period.
Neuropsychological impairment is a key feature of late-life depression, with deficits observed across multiple domains. However, it is unclear whether deficits in multiple domains represent relatively independent processes with specific neural correlates or whether they can be explained by cognitive deficits in executive function or processing speed.
Method
We examined group differences across five domains (episodic memory; executive function; language skills; processing speed; visuospatial skills) in a sample of 36 depressed participants and 25 control participants, all aged ⩾60 years. The influence of executive function and processing speed deficits on other neuropsychological domains was also investigated. Magnetic resonance imaging correlates of executive function, processing speed and episodic memory were explored in the late-life depression group.
Results
Relative to controls, the late-life depression group performed significantly worse in the domains of executive function, processing speed, episodic memory and language skills. Impairments in executive function or processing speed were sufficient to explain differences in episodic memory and language skills. Executive function was correlated with anisotropy of the anterior thalamic radiation and uncinate fasciculus; processing speed was correlated with anisotropy of genu of the corpus callosum. Episodic memory was correlated with anisotropy of the anterior thalamic radiation, the genu and body of the corpus callosum and the fornix.
Conclusions
Executive function and processing speed appear to represent important cognitive deficits in late-life depression, which contribute to deficits in other domains, and are related to reductions in anisotropy in frontal tracts.
Converging evidence implicates basal ganglia alterations in impulsivity and suicidal behavior. For example, D2/D3 agonists and subthalamic nucleus stimulation in Parkinson's disease (PD) trigger impulse control disorders and possibly suicidal behavior. Furthermore, suicidal behavior has been associated with structural basal ganglia abnormalities. Finally, low-lethality, unplanned suicide attempts are associated with increased discounting of delayed rewards, a behavior dependent upon the striatum. Thus, we tested whether, in late-life depression, changes in the basal ganglia were associated with suicide attempts and with increased delay discounting.
Method
Fifty-two persons aged ⩾60 years underwent extensive clinical and cognitive characterization: 33 with major depression [13 suicide attempters (SA), 20 non-suicidal depressed elderly] and 19 non-depressed controls. Participants had high-resolution T1-weighted magnetization prepared rapid acquisition gradient–echo (MPRAGE) magnetic resonance imaging (MRI) scans. Basal ganglia gray matter voxel counts were estimated using atlas-based segmentation, with a highly deformable automated algorithm. Discounting of delayed rewards was assessed using the Monetary Choice Questionnaire (MCQ) and delay aversion with the Cambridge Gamble Task (CGT).
Results
SA had lower putamen but not caudate or pallidum gray matter voxel counts, compared to the control groups. This difference persisted after accounting for substance use disorders and possible brain injury from suicide attempts. SA with lower putamen gray matter voxel counts displayed higher delay discounting but not delay aversion. Secondary analyses revealed that SA had lower voxel counts in associative and ventral but not sensorimotor striatum.
Conclusions
Our findings, although limited by small sample size and the case–control design, suggest that striatal lesions could contribute to suicidal behavior by increasing impulsivity.
The reasons for the high prevalence of depressive disorders in women of Pakistani origin living in the UK are not clear. The aim of this study was to determine the relative importance of life events, chronic social difficulties and acculturation in a population-based sample of British Pakistani women.
Method
A cross-sectional and prospective cohort study of 18- to 65-year-old Pakistani women in UK was carried out. The Schedule for Clinical Assessment in Neuropsychiatry for diagnosis, the Life Events and Difficulties Schedule for social stress and an acculturation questionnaire were used.
Results
Depressive disorder at baseline was associated with older age, social isolation and marked difficulties involving health and close relationships. Depressive disorder at follow-up was associated with severity of depression at baseline, difficulties in close relationships and two aspects of acculturation, especially less acculturation in relation to use of the English language.
Conclusions
Lack of acculturation, especially less familiarity with the English language, is an independent predictor of persistence of depression in Pakistani women in UK. This needs to be taken into consideration when planning treatment, which also needs to address the personal difficulties associated with persistent depression. The implication of this work is that women of Pakistani origin with depression should be encouraged to receive help in the use of English as one part of treatment that may prevent relapse.
This study examined the prevalence of major depressive disorder (MDD), and the correlations and co-morbid conditions associated with MDD, in the adult Taiwanese population, which a previous estimate in the 1980s had found to be at the lower end of the spectrum worldwide. Possible explanations for the reported low prevalence of MDD were evaluated.
Method
As part of a survey of common psychiatric disorders in a nationally representative sample of individuals aged ⩾18 years who were non-institutionalized civilians in Taiwan, a face-to-face interview using the paper version of the World Mental Health Survey of the World Health Organization (WHO) Composite International Diagnostic Interview (WMH-CIDI) was conducted between 2003 and 2005. Functional impairment and help-seeking behaviors were compared between Taiwanese subjects with MDD and their counterparts in the USA.
Results
Among the 10 135 respondents, the lifetime prevalence of MDD was 1.20% [standard error (s.e.)=0.2%]. Individuals who were divorced or widowed, aged ⩽40 years, and female were at increased risk, whereas rural residents were at lower risk for MDD. The proportion of MDD cases co-morbid with other psychiatric disorders in this study was much lower than in the US study. Only one-third of Taiwanese individuals with MDD sought help despite having twice the number of lost workdays compared with the US sample.
Conclusions
Despite the low prevalence of MDD in Taiwanese adults, the pattern of low help-seeking behavior and profound functional impairment indicates much room for improvement in the early detection of and intervention in major depression in this population.
Studies conducted in Europe and the USA have shown that co-morbidity between major depressive disorder (MDD) and anxiety disorders is associated with various MDD-related features, including clinical symptoms, degree of familial aggregation and socio-economic status. However, few studies have investigated whether these patterns of association vary across different co-morbid anxiety disorders. Here, using a large cohort of Chinese women with recurrent MDD, we examine the prevalence and associated clinical features of co-morbid anxiety disorders.
Method
A total of 1970 female Chinese MDD patients with or without seven co-morbid anxiety disorders [including generalized anxiety disorder (GAD), panic disorder, and five phobia subtypes] were ascertained in the CONVERGE study. Generalized linear models were used to model association between co-morbid anxiety disorders and various MDD features.
Results
The lifetime prevalence rate for any type of co-morbid anxiety disorder is 60.2%. Panic and social phobia significantly predict an increased family history of MDD. GAD and animal phobia predict an earlier onset of MDD and a higher number of MDD episodes, respectively. Panic and GAD predict a higher number of DSM-IV diagnostic criteria. GAD and blood-injury phobia are both significantly associated with suicidal attempt with opposite effects. All seven co-morbid anxiety disorders predict higher neuroticism.
Conclusions
Patterns of co-morbidity between MDD and anxiety are consistent with findings from the US and European studies; the seven co-morbid anxiety disorders are heterogeneous when tested for association with various MDD features.
Genetic studies in adults indicate that genes influencing the personality trait of neuroticism account for substantial genetic variance in anxiety and depression and in somatic health. Here, we examine for the first time the factors underlying the relationship between neuroticism and anxiety/depressive and somatic symptoms during adolescence.
Method
The Somatic and Psychological Health Report (SPHERE) assessed symptoms of anxiety/depression (PSYCH-14) and somatic distress (SOMA-10) in 2459 adolescent and young adult twins [1168 complete pairs (35.4% monozygotic, 53% female)] aged 12–25 years (mean=15.5±2.9). Differences between boys and girls across adolescence were explored for neuroticism, SPHERE-34, and the subscales PSYCH-14 and SOMA-10. Trivariate analyses partitioned sources of covariance in neuroticism, PSYCH-14 and SOMA-10.
Results
Girls scored higher than boys on both neuroticism and SPHERE, with SPHERE scores for girls increasing slightly over time, whereas scores for boys decreased or were unchanged. Neuroticism and SPHERE scores were strongly influenced by genetic factors [heritability (h2)=40–52%]. A common genetic source influenced neuroticism, PSYCH-14 and SOMA-10 (impacting PSYCH-14 more than SOMA-10). A further genetic source, independent of neuroticism, accounted for covariation specific to PSYCH-14 and SOMA-10. Environmental influences were largely specific to each measure.
Conclusions
In adolescence, genetic risk factors indexed by neuroticism contribute substantially to anxiety/depression and, to a lesser extent, perceived somatic health. Additional genetic covariation between anxiety/depressive and somatic symptoms, independent of neuroticism, had greatest influence on somatic distress, where it was equal in influence to the factor shared with neuroticism.
Non-medical use of prescription opioids represents a national public health concern of growing importance. Mood and anxiety disorders are highly associated with non-medical prescription opioid use. The authors examined longitudinal associations between non-medical prescription opioid use and opioid disorder due to non-medical opioid use and mood/anxiety disorders in a national sample, examining evidence for precipitation, self-medication and general shared vulnerability as pathways between disorders.
Method
Data were drawn from face-to-face surveys of 34 653 adult participants in waves 1 and 2 of the National Epidemiologic Survey on Alcohol and Related Conditions. Logistic regression models explored the temporal sequence and evidence for the hypothesized pathways.
Results
Baseline lifetime non-medical prescription opioid use was associated with incidence of any mood disorder, major depressive disorder (MDD), bipolar disorder, any anxiety disorder and generalized anxiety disorder (GAD in wave 2, adjusted for baseline demographics, other substance use, and co-morbid mood/anxiety disorders). Lifetime opioid disorder was not associated with any incident mood/anxiety disorders. All baseline lifetime mood disorders and GAD were associated with incident non-medical prescription opioid use at follow-up, adjusted for demographics, co-morbid mood/anxiety disorders, and other substance use. Baseline lifetime mood disorders, MDD, dysthymia and panic disorder were associated with incident opioid disorder due to non-medical prescription opioid use at follow-up, adjusted for the same covariates.
Conclusions
These results suggest that precipitation, self-medication as well as shared vulnerability are all viable pathways between non-medical prescription opioid use and opioid disorder due to non-medical opioid use and mood/anxiety disorders.
Tobacco smoking and poor mental health are both prevalent and detrimental health problems in young women. The temporal relationship between the two variables is unclear. We investigated the prospective bi-directional relationship between smoking and mental health over 13 years.
Method
Participants were a randomly selected community sample of 10 012 young women with no experience of pregnancy, aged 18–23 years at baseline (1996) from the Australian Longitudinal Study on Women's Health. Follow-up surveys over 13 years were completed in 2000, 2003, 2006 and 2009, allowing for five waves of data. Measures included self-reported smoking and mental health measured by the Mental Health Index from the 36-item short-form health questionnaire and the 10-item Center for Epidemiologic Studies Depression Scale. Sociodemographic control variables included marital status, education level and employment status.
Results
A strong cross-sectional dose–response relationship between smoking and poor mental health was found at each wave [odds ratio (OR) 1.41, 95% confidence intervals (CI) 1.17–1.70 to OR 2.27, 95% CI 1.82–2.81]. Longitudinal results showed that women who smoked had 1.21 (95% CI 1.06–1.39) to 1.62 (95% CI 1.24–2.11) times higher odds of having poor mental health at subsequent waves. Women with poor mental health had 1.12 (95% CI 1.17–1.20) to 2.11 (95% CI 1.68–2.65) times higher odds of smoking at subsequent waves. These results held after adjusting for mental health history and smoking history and sociodemographic factors. Correlation analysis and structural equation modelling results were consistent in showing that both directions of the relationship were statistically significant.
Conclusions
The association between poor mental health and smoking in young women appeared to be bi-directional.
Traumatized individuals and particularly post-traumatic stress disorder (PTSD) patients are characterized by memory disturbances that suggest altered memory control. The present study investigated the issue using an item method, directed forgetting (DF) paradigm in 51 civil war victims in Uganda. All participants had been exposed to severe traumatic stress and 26 additionally suffered from PTSD.
Method
In an item cued, DF paradigm photographs were presented, each followed by an instruction to either remember or forget it. A recognition test for all initially presented photographs and thematically similar distracters followed. DF patterns were compared between the non-PTSD and the PTSD groups. Post-experimental ratings of picture valence and arousal were collected and correlated with DF.
Results
Results revealed DF, that is, reduced recognition for ‘to-be-forgotten’ items in the non-PTSD but not in the PTSD group. Moreover, in the non-PTSD, but not in the PTSD group, false alarms were reduced for ‘to-be-remembered’ items. Finally, DF was reduced in those participants who rated the pictures as more arousing, the PTSD group giving, on average, higher arousal ratings.
Conclusions
Data indicate that DF is reduced in PTSD and that the reduction is related to stimulus arousal. Furthermore, individuals with PTSD are characterized by a more global encoding style than individuals without PTSD, reflected in a higher false alarm rate. In sum, traumatized individuals with (but not without) PTSD are impaired in their ability to selectively control episodic memory encoding. This impairment may contribute to clinical features of the disorder such as intrusions and flashbacks.
Associations between early life maltreatment, social information processing (SIP) and aggression in childhood and adolescence have been widely documented. Few studies have examined the importance of childhood maltreatment independent of SIP in the etiology of adult aggression. Furthermore, moderating effects of childhood maltreatment on the SIP–aggression links have not been explored.
Method
Hierarchical, multi-level models were fitted to data from n=2752 twins aged 20–55 years from the PennTwins Cohort. Adult aggression was assessed with the Life History of Aggression questionnaire. Childhood maltreatment was measured using the Childhood Trauma Questionnaire. Two aspects of SIP were examined: hostile attribution biases (HAB); negative emotional responses (NER).
Results
Childhood maltreatment was positively correlated with adult aggression, independently of HAB and NER. In addition, childhood maltreatment moderated the relationships between both aspects of SIP and adult aggression. Specifically, the relationship between NER and aggression was stronger among individuals with higher levels of childhood maltreatment and NER was not associated with aggression for adults who experienced low levels of childhood maltreatment. Moderating effects of childhood maltreatment on the NER–aggression link were supported for total childhood maltreatment, emotional neglect and emotional abuse. In contrast, HAB was more strongly associated with adult aggression at lower levels of emotional abuse and physical neglect.
Conclusions
The current study provides insight into the mechanisms by which early life experiences influence adult aggression. Our findings suggest that childhood maltreatment may not only lead to increased levels of aggression in adulthood but may also modify the associations between SIP and adult aggression.
Individual differences in fear and fearlessness have been investigated at their extremes in relation to markedly different forms of psychopathology – anxiety disorders and psychopathy, respectively. A documented neural substrate of fear-related traits and disorders is defensive reactivity as reflected in aversive startle potentiation (ASP).
Method
The current study extended prior work by characterizing, in a sample of adult twins from the community (n=2511), the phenotypic and etiologic structure of self-report measures of fear and fearlessness known to be associated with ASP.
Results
Analyses revealed a hierarchical structure to the trait fear domain, with an overarching, bipolar fear/fearlessness dimension saturating each measure in this domain, and subfactors labeled ‘distress,’ ‘stimulation seeking’ and ‘sociability’ accounting for additional variance in particular measures. The structure of genetic and non-shared environmental associations among the measures closely mirrored the phenotypic structure of the domain.
Conclusions
The findings have implications for proposals to reconceptualize psychopathology in neurobiological terms.
There is now strong evidence that cannabis use increases the risk of psychoses including schizophrenia, but the relationship between cannabis and different psychotic disorders, as well as the mechanisms, are poorly known. We aimed to assess types of psychotic outcomes after use of cannabis in adolescence and variation in risk over time.
Method
A cohort of 50 087 military conscripts with data on cannabis use in late adolescence was followed up during 35 years with regard to in-patient care for psychotic diagnoses.
Results
Odds ratios for psychotic outcomes among frequent cannabis users compared with non-users were 3.7 [95% confidence interval (CI) 2.3–5.8] for schizophrenia, 2.2 (95% CI 1.0–4.7) for brief psychosis and 2.0 (95% CI 0.8–4.7) for other non-affective psychoses. Risk of schizophrenia declined over the decades in moderate users but much less so in frequent users. The presence of a brief psychosis did not increase risk of later schizophrenia more in cannabis users compared with non-users.
Conclusions
Our results confirm an increased risk of schizophrenia in a long-term perspective, although the risk declined over time in moderate users.
The increased occurrence of obstetric complications (OCs) in patients with schizophrenia suggests that alterations in neurodevelopment may be of importance to the aetiology of the illness. Abnormal cortical folding may reflect subtle deviation from normal neurodevelopment during the foetal or neonatal period. In the present study, we hypothesized that OCs would be related to cortical folding abnormalities in schizophrenia patients corresponding to areas where patients with schizophrenia display altered cortical folding when compared with healthy controls.
Method
In total, 54 schizophrenia patients and 54 healthy control subjects underwent clinical examination and magnetic resonance image scanning on a 1.5 T scanner. Information on OCs was collected from original birth records. An automated algorithm was used to calculate a three-dimensional local gyrification index (lGI) at numerous points across the cortical mantle.
Results
In both schizophrenia patients and healthy controls, an increasing number of OCs was significantly related to lower lGI in the left pars triangularis (p<0.0005) in Broca's area. For five other anatomical cortical parcellations in the left hemisphere, a similar trend was demonstrated. No significant relationships between OCs and lGI were found in the right hemisphere and there were no significant case–control differences in lGI.
Conclusions
The reduced cortical folding in the left pars triangularis, associated with OCs in both patients and control subjects suggests that the cortical effect of OCs is caused by factors shared by schizophrenia patients and healthy controls rather than factors related to schizophrenia alone.