Bulimic eating disorders are common among female students, yet the majority do not access effective treatment. Internet-based cognitive-behavioural therapy (iCBT) may be able to bridge this gap.

Seventy-six students with bulimia nervosa (BN) or eating disorder not otherwise specified (EDNOS) were randomly assigned to immediate iCBT with e-mail support over 3 months or to a 3-month waiting list followed by iCBT [waiting list/delayed treatment control (WL/DTC)]. ED outcomes were assessed with the Eating Disorder Examination (EDE) at baseline, 3 months and 6 months. Other outcomes included depression, anxiety and quality of life.

Students who had immediate iCBT showed significantly greater improvements at 3 and 6 months than those receiving WL/DTC in ED and other symptoms.

iCBT with e-mail support is efficacious in students with bulimic disorders and has lasting effects.

Cognitive remediation is frequently based on computerized training methods that target different cognitive deficits. The aim of this article was to assess the efficacy of computer-assisted cognitive remediation (CACR) in schizophrenia and to determine whether CACR enables selective treatment of specific cognitive domains.

A meta-analysis was performed on 16 randomized controlled trials evaluating CACR. The effect sizes of differences between CACR and control groups were computed and classified according to the cognitive domain assessed. The possible influences of four potential moderator variables were examined: participants' age, treatment duration, weekly frequency, and control condition type. To test the domain-specific effect, the intended goal of each study was determined and the effect sizes were sorted accordingly. The effect sizes of the cognitive domains explicitly targeted by the interventions were then compared with those that were not.

CACR enhanced general cognition with a mean effect size of 0.38 [confidence interval (CI) 0.20–0.55]. A significant medium effect size of 0.64 (CI 0.29–0.99) was found for Social Cognition. Improvements were also significant in Verbal Memory, Working Memory, Attention/Vigilance and Speed of Processing with small effect sizes. Cognitive domains that were specifically targeted by the interventions did not yield higher effects than those that were not.

The results lend support to the efficacy of CACR with particular emphasis on Social Cognition. The difficulty in targeting specific domains suggests a ‘non-specific’ effect of CACR. These results are discussed in the light of the possible bias in remediation tasks due to computer interface design paradigms.

Clinically ascertained reports suggest that boys and girls with attention deficit hyperactivity disorder (ADHD) may differ from each other in their vulnerability to substance use problems.

A total of 1545 Finnish adolescents were assessed for DSM-IV-based ADHD symptoms by their parents and classroom teachers using standardized rating scales at age 11–12 years. At age 14, substance use disorders and psychiatric co-morbidity were assessed with the Semi-Structured Assessment for the Genetics of Alcoholism, providing DSM-III-R/DSM-IV diagnoses for Axis I disorders. At age 17.5, substance use was assessed by multi-item questionnaire.

Although baseline ADHD symptoms were less common among females, they were more predictive of adverse substance use outcomes once conduct disorder and previous substance use were controlled for. Only in females were baseline ADHD symptoms significant predictors of alcohol abuse and dependence and illicit drug use at age 14. At the age of 17.5, parents' reports of inattentiveness and hyperactivity were significant predictors for frequent alcohol use in both sexes, but they were more predictive of frequent alcohol and illicit drug use in girls. Impulsivity in teachers' ratings predicted frequent alcohol use and illicit drug use in boys. Parental reports of inattentiveness in their 11-/12-year-old daughters were a consistent predictor for illicit drug use across adolescence.

Inattentiveness and hyperactivity may be more predictive of alcohol use disorders and maladaptive patterns of alcohol and illicit drug use among girls than boys. The importance of these behavioural symptoms should be assessed further in the community, as they could jeopardize adolescents' successful transitioning into adult roles.

The stress response involves the activation of the hypothalamic–pituitary–adrenal (HPA) axis and the sympathetic nervous system (SNS). As a role for stress in determining of the onset and the natural course of eating disorders (EDs) has been proposed, the study of the psychobiology of the stress response in patients with anorexia nervosa (AN) and bulimia nervosa (BN) should be helpful in understanding the pathophysiology of these disorders. The two neurobiological components of the stress response can be easily explored in humans by the measurement of salivary cortisol and α-amylase response to a stressor. Therefore, we assessed salivary cortisol and α-amylase responses to the Trier Social Stress Test (TSST) in symptomatic patients with AN and BN compared to healthy controls.

Seven AN women, eight BN women and eight age-matched healthy females underwent the TSST between 1530 and 1700 h. Salivary cortisol and α-amylase levels were measured by an enzyme-linked immunosorbent assay (ELISA).

Compared to healthy women, AN patients showed a normal cortisol response to the TSST, although this occurred at significantly increased hormone levels, and an almost complete absence of response of α-amylase. BN women, however, exhibited enhanced pre-stress levels of salivary α-amylase but a normal response of the enzyme and cortisol to the TSST.

These findings demonstrate, for the first time, the occurrence of an asymmetry between the HPA axis and SNS components of the stress response in the acute phase of AN but not in BN. The pathophysiological significance of this asymmetry remains to be determined.

The cognitive behavioural model of chronic fatigue syndrome (CFS) suggests that the illness is caused through reciprocal interactions between physiology, cognition, emotion and behaviour. The purpose of this study was to investigate whether the psychological factors operationalized in this model could predict the onset of CFS following an acute episode of infectious mononucleosis commonly known as glandular fever (GF).

A total of 246 patients with GF were recruited into this prospective cohort study. Standardized self-report measures of perceived stress, perfectionism, somatization, mood, illness beliefs and behaviour were completed at the time of their acute illness. Follow-up questionnaires determined the incidence of new-onset chronic fatigue (CF) at 3 months and CFS at 6 months post-infection.

Of the participants, 9.4% met the criteria for CF at 3 months and 7.8% met the criteria for CFS at 6 months. Logistic regression revealed that factors proposed to predispose people to CFS including anxiety, depression, somatization and perfectionism were associated with new-onset CFS. Negative illness beliefs including perceiving GF to be a serious, distressing condition, that will last a long time and is uncontrollable, and responding to symptoms in an all-or-nothing behavioural pattern were also significant predictors. All-or-nothing behaviour was the most significant predictor of CFS at 6 months. Perceived stress and consistently limiting activity at the time of GF were not significantly associated with CFS.

The findings from this study provide support for the cognitive behavioural model and a good basis for developing prevention and early intervention strategies for CFS.

The DSM-V Working Group is currently re-evaluating distress as a primary diagnostic criterion for female sexual dysfunction (FSD). Here, for the first time, we explored the epidemiology of sexual distress and its putative aetiological relationship to FSD by estimating the influence of genetic and environmental risk factors.

Questionnaire data on a representative sample of 930 British female twins using validated scales of FSD and sexual distress were subject to variance components analyses to quantify latent genetic and environmental factors influencing phenotypic variation and covariation. Multiple regression analyses were used to identify other potential risk factors of sexual distress.

Of 319 women with any sexual problems, only 36.5% reported distress. Of women classified as functional, 16.5% felt sexual distress. Sexual distress had a heritability of 44% [95% confidence interval (CI) 0.33–0.54]. Bivariate analysis suggested that the majority (91% CI 86–99%) of the covariance between sexual distress and FSD was due to unique environmental effects common to both traits. Associations were found between sexual distress and other risk variables, including relationship dissatisfaction [odds ratio (OR) 1.6, p<0.001], anxiety sensitivity and obsessive–compulsive symptomatology (OR 1.2, p<0.01, for both).

There seems to be a weak phenotypic and genetic basis for including sexual distress as a diagnostic indicator of FSD. Instead, the data indicate that unrelated psychological factors play an important role in sexual distress and tentatively suggest that sexual distress is less a consequence of FSD and more related to general anxiety among women.

Alcohol consumption is influenced by specific genetic risk factors for alcohol use disorders (AUDs), non-specific genetic risk factors for externalizing behaviors and various environmental experiences. We have limited knowledge of how these risk factors inter-relate through development.

Retrospective assessments in 1796 adult male twins using a life history calendar of key environmental exposures and alcohol consumption from early adolescence to mid-adulthood. Analysis by linear mixed models.

The importance of non-specific genetic risk factors on maximal alcohol consumption rose rapidly in early to mid-adolescence, peaked at ages 15–17 years and then declined slowly. Alcohol-specific genetic risk factors increased slowly in influence through mid-adulthood. We detected robust evidence for environmental moderation of genetic effects on alcohol consumption that was more pronounced in early and mid-adolescence than in later periods. Alcohol availability, peer deviance and low prosocial behaviors showing the strongest moderation effects. More interactions with environmental risk factors were seen for the non-specific externalizing disorder risk than for specific genetic risk for AUDs.

The impact of specific and non-specific genetic influences on alcohol consumption have different development trajectories. Genetic effects on alcohol use are more pronounced when social constraints are minimized (e.g. low prosocial behaviors or parental monitoring) or when the environment permits easy access to alcohol and/or encourages its use (e.g. high alcohol availability or peer deviance). Gene–environment interactions influencing alcohol intake may be more robust at younger ages, indicating greater plasticity of genetic influences early in the development of drinking patterns.

Little is known about the long-term mental health of extremely low birth weight (ELBW) (<1000 g) survivors. We test whether young adults aged 22 to 26 years born at ELBW differ from normal birth weight (NBW) controls in self-reported levels of psychopathology.

Participants included 142 ELBW survivors (86% response) born between 1977 and 1982 to residents of central-west Ontario, Canada and 133 NBW control subjects (92% response). The Young Adult Self-Report measure was used to create five DSM-IV oriented scales aggregated to form internalizing (depressive problems, anxiety problems, avoidant personality problems) and externalizing (attention deficit-hyperactivity disorder problems and antisocial personality problems) scales.

After adjusting for family background characteristics, mean scores for ELBW survivors were 3.02 [95% confidence interval (CI) 0.78–5.26] points higher for internalizing problems and no different, i.e. 0.00 (95% CI −1.17 to 1.17), for externalizing problems. There was a sex×group statistical interaction such that being male muted the risk for externalizing problems among those born at ELBW: −2.11 (95% CI −4.21 to −0.01). Stratifying ELBW adults as born small for gestational age (SGA) versus appropriate weight for gestational age (AGA) revealed a significant gradient of risk for levels of internalizing problems that was largest for SGA, i.e. 4.75 (95% CI 1.24–8.26), and next largest for AGA, 2.49 (95% CI 0.11–4.87), compared with NBW controls.

Depression, anxiety and avoidant personality problems (internalizing problems) are elevated in young adulthood among ELBW survivors. This effect is relatively small overall but noticeably larger among ELBW survivors born SGA.

Cannabis use is associated with psychosis and a range of subclinical psychiatric symptoms. The strength of this association depends on dosage and age at first use. The current study investigates whether level of cannabis exposure and starting age are associated with specific profiles of subclinical symptoms.

We collected cross-sectional data from a young adult population sample by administering an online version of the Community Assessment of Psychic Experiences (CAPE). Cannabis exposure was quantified as the amount of Euros spent on cannabis per week and the age of initial cannabis use. The primary outcome measure was the odds ratio (OR) to belong to the highest 10% of scores on the total CAPE and the positive-, negative- and depressive symptom dimensions.

In 17 698 adolescents (mean age 21.6, s.d.=4.2 years), cannabis use at age 12 years or younger was strongly associated with a top 10% score on psychotic experiences [OR 3.1, 95% confidence interval (CI) 2.1–4.3] and to a lesser degree with negative symptoms (OR 1.7, 95% CI 1.1–2.5). The OR of heavy users (>€25/week) for negative symptoms was 3.4 (95% CI 2.9–4.1), for psychotic experiences 3.0 (95% CI 2.4–3.6), and for depressive symptoms 2.8 (95% CI 2.3–3.3).

Early start of cannabis use is strongly associated with subclinical psychotic symptoms and to a lesser degree with negative symptoms, while smoking high amounts of cannabis is associated with increased levels of all three symptom dimensions: psychotic, negative and depressive. These results support the hypothesis that the impact of cannabis use is age specific.

Serotonin and dopamine neurotransmitter systems are implicated in the regulation of mood, cognition and personality traits and their dysfunction is thought to be implicated in diverse psychopathologies. However, in healthy subjects the relationship between the serotonin and dopamine systems and neuropsychological functioning and personality traits is not clearly established. In the present study we investigated whether neuropsychological functioning, personality traits and mood states of a group of healthy subjects are associated with in vivo measures of serotonin transporters (SERTs) and dopamine transporters (DATs).

A total of 188 young healthy subjects underwent neuropsychological and subjective measurements of memory function, depression and impulsivity. Participants' SERT and DAT availability in predefined regions of interest were assessed using single photon emission computed tomography (SPECT) with the radiotracer [123I]β-CIT. Individual magnetic resonance imaging (MRI) scans served as anatomic reference.

We did not find any significant association between SERT or DAT availability and neuropsychological test performance or self-reported impulsivity and mood. There were no significant sex differences in SERT or DAT availability, but men performed significantly better on some tests of visuospatial functioning than women.

Robust negative findings for striatal DAT availability seriously question earlier findings of positive associations between DAT availability and cognitive functions in healthy subjects. Our results also suggest that subcortical SERT availability is not associated with the neuropsychological functions and personality traits assessed. In summary, the present study suggests that neuropsychological and personality measurements in young healthy people are not associated with subcortical SERT or striatal DAT availabilities in the brain.

The study aims to explore, using indirect ecological measures of exposure, the role of viral infections in the development of anorexia nervosa (AN).

The cohort of participants consisted of all female subjects born in the Veneto region in the period between 1970 and 1984, and residing in the urban and suburban area of Padua (27 682 female subjects in an area of 424 km2). The main outcome measure was the diagnosis of AN resulting from the Public Mental Health Database, the Register of Hospital Admissions, and the Register of the Eating Disorders Unit (n=402, 1.4%). The number of cases of rubella, chickenpox, influenza and measles was ascertained for each month for the 15-year period.

Exposures during the sixth month of pregnancy to the peaks of chickenpox [odds ratio (OR) 1.6, 95% confidence interval (CI) 1.2–2.0] and rubella infections (OR 1.5, 95% CI 1.1–2.0) were significantly associated with an increased risk of developing AN, even after controlling for socio-economic status, urbanization and month of birth. We found weak evidence of a season-of-birth bias.

In utero exposure to viral infection could be a risk factor for developing AN. We need further epidemiological and serological studies to confirm this hypothesis.

Traumatic life events are generally more common in patients with borderline personality disorder (BPD) than in non-patients or patients with other personality disorders. This study investigates whether exposure to life events moderates the genetic architecture of BPD features. As the presence of genotype–environment correlation (rGE) can lead to spurious findings of genotype–environment interaction (G×E), we also test whether BPD features increase the likelihood of exposure to life events.

The extent to which an individual is at risk to develop BPD was assessed with the Personality Assessment Inventory – Borderline features scale (PAI-BOR). Life events under study were a divorce/break-up, traffic accident, violent assault, sexual assault, robbery and job loss. Data were available for 5083 twins and 1285 non-twin siblings. Gene–environment interaction and correlation were assessed by using structural equation modelling (SEM) and the co-twin control design.

There was evidence for both gene–environment interaction and correlation. Additive genetic influences on BPD features interacted with the exposure to sexual assault, with genetic variance being lower in exposed individuals. In individuals who had experienced a divorce/break-up, violent assault, sexual assault or job loss, environmental variance for BPD features was higher, leading to a lower heritability of BPD features in exposed individuals. Gene–environment correlation was present for some life events. The genes that influence BPD features thus also increased the likelihood of being exposed to certain life events.

To our knowledge, this study is the first to test the joint effect of genetic and environmental influences and the exposure to life events on BPD features in the general population. Our results indicate the importance of both genetic vulnerability and life events.

Pathological gambling (PG) is a form of behavioural addiction that has been associated with elevated impulsivity and also cognitive distortions in the processing of chance, probability and skill. We sought to assess the relationship between the level of cognitive distortions and state and trait measures of impulsivity in treatment-seeking pathological gamblers.

Thirty pathological gamblers attending the National Problem Gambling Clinic, the first National Health Service clinic for gambling problems in the UK, were compared with 30 healthy controls in a case-control design. Cognitive distortions were assessed using the Gambling-Related Cognitions Scale (GRCS). Trait impulsivity was assessed using the UPPS-P, which includes scales of urgency, the tendency to be impulsive in positive or negative mood states. Delay discounting rates were taken as a state measure of impulsive choice.

Pathological gamblers had elevated impulsivity on several UPPS-P subscales but effect sizes were largest (Cohen's d>1.4) for positive and negative urgency. The pathological gamblers also displayed higher levels of gambling distortions, and elevated preference for immediate rewards, compared to controls. Within the pathological gamblers, there was a strong relationship between the preference for immediate rewards and the level of cognitive distortions (R2=0.41).

Impulsive choice in the gamblers was correlated with the level of gambling distortions, and we hypothesize that an impulsive decision-making style may increase the acceptance of erroneous beliefs during gambling play.

This study sought to determine the social and emotional impact of maternal loss on Aboriginal children and young people using data from the Western Australian Aboriginal Child Health Survey (WAACHS).

Data were from a population-based random sample of 5289 Aboriginal children aged under 18 years. Interview data about the children were gathered from primary carers and from their school teachers. Probabilistic record linkage to death registrations was used to ascertain deaths. Association between maternal death and subsequent psychosocial outcomes was assessed using univariate analyses and logistic regression.

Of the 5289 Aboriginal children, 57 had experienced the death of their birth mother prior to the survey. Multi-variable adjustment accounting for age and gender found that, relative to children who were living with their birth mother, children whose birth mother had died were at higher risk for sniffing glue or other substances [odds ratio (OR) 3.4, 95% confidence interval (CI) 1.3–8.7], using other drugs (OR 2.8, 95% CI 1.2–6.8), talking about suicide (OR 2.6, 95% CI 1.2–5.7) and attempting suicide (OR 7.0, 95% CI 1.6–31.1).

Although the death of a birth mother is relatively rare and the vast majority of Aboriginal children with adverse developmental outcomes live in families and are cared for by their birth mother, the findings here suggest that the loss of a birth mother and the circumstances arising from this impart a level of onward developmental risk for mental health morbidity in Australian Aboriginal children.

Depression and anxiety have been shown to be associated with obesity and underweight, but little is known about how the relationship varies across the life course, from adolescence through adulthood. We aimed to investigate the association between adolescent- and adult-onset affective symptoms and body mass index (BMI) change from age 15 to 53 years.

We used data from a British birth cohort born in 1946 and followed up ever since. The relationship between affective symptom profiles, distinguishing adolescent-onset and adult-onset symptoms, and BMI change from adolescence to age 53 years was investigated using multilevel models.

Women with adolescent-onset symptoms had lower mean BMI at age 15 years, faster rates of increase across adulthood, and higher BMI at age 53 years than those with no symptoms. Men with adolescent-onset symptoms had lower BMI at all ages from 15 to 53 years. The BMI trajectories of men and women with adult-onset symptoms did not differ from those with absence of symptoms at all ages.

The relationship between affective symptoms and change in BMI varies by sex and age at onset of symptoms. Adolescence may be an important period for the development of the association between affective symptoms and weight gain in girls. Intervention to prevent increases in BMI across adult life in women with adolescent-onset symptoms, even if they are not overweight at this age, should be considered.

ICD-10 includes a craving criterion for alcohol dependence while DSM-IV does not. Little is known about whether craving fits with or improves the DSM-IV criteria set for alcohol-use disorders.

Data were derived from current drinkers (n=18 352) in the 1991–1992 National Longitudinal Alcohol Epidemiologic Survey (NLAES), a nationally representative survey of US adults >17 years of age. The Alcohol Use Disorder and Associated Disabilities Interview Schedule was used to assess the eleven DSM-IV dependence and abuse criteria, and alcohol craving. Exploratory factor, item response theory, and regression analyses were used to evaluate the psychometric properties and concurrent validity of DSM-based alcohol disorder criteria with the addition of alcohol craving.

The past 12-month prevalence of craving was 1.3%. Craving formed part of a unidimensional latent variable that included existing DSM-IV criteria. Craving demonstrated high severity on the alcohol-use disorder continuum, resulting in an improved dimensional model with greater discriminatory ability compared with current DSM-IV criteria. Correlates of the diagnosis did not change with the addition of craving, and past 12-month craving was associated with prior alcohol dependence, depression, and earlier age of alcohol disorder onset among those with current DSM-IV alcohol dependence.

The addition of craving to the existing DSM-IV criteria yields a continuous measure that better differentiates individuals with and without alcohol problems along the alcohol-use disorder continuum. Few individuals are newly diagnosed with alcohol dependence given the addition of craving, indicating construct validity but redundancy with existing criteria.

Hypochondriasis is common in the clinic and in the community. Cognitive behavioural therapy (CBT) has been found to be effective in previous trials. Psychodynamic psychotherapy is a treatment routinely offered to patients with hypochondriasis in many countries, including Denmark. The aim of this study was to test CBT for hypochondriasis in a centre that was not involved in its development and compare both CBT and short-term psychodynamic psychotherapy (STPP) to a waiting-list control and to each other. CBT was modified by including mindfulness and group therapy sessions, reducing the therapist time required. STPP consisted of individual sessions.

Eighty patients randomized to CBT, STPP and the waiting list were assessed on measures of health anxiety and general psychopathology before and after a 6-month treatment period. Waiting-list patients were subsequently offered one of the two active treatments on the basis of re-randomization, and assessed on the same measures post-treatment. Patients were again assessed at 6- and 12-month follow-up points.

Patients who received CBT did significantly better on all measures relative to the waiting-list control group, and on a specific measure of health anxiety compared with STPP. The STPP group did not significantly differ from the waiting-list group on any outcome measures. Similar differences were observed between CBT and STPP during follow-up, although some of the significant differences between groups were lost.

A modified and time-saving CBT programme is effective in the treatment of hypochondriasis, although the two psychotherapeutic interventions differed in structure.

To date, the genetic and environmental architecture of the dimensions of psychological well-being (PWB) remains unexplored.

PWB of 742 twins aged 23–24 years and enrolled in the Italian Twin Registry was assessed with the three-item version of Ryff's Scales of Psychological Well-Being (SPWB). These scales include items for evaluating the PWB dimensions of self-acceptance, positive relations with others, autonomy, environmental mastery, purpose in life, and personal growth. A twin design was used to obtain correlations in the PWB dimensions for monozygotic (MZ) and dizygotic (DZ) twins and to estimate the contribution of genetic and environmental factors to variation and covariation in the dimensions.

Genetic factors explained moderate to substantial proportions of variance in the six SPWB dimensions, with heritability estimates between 37% and 64%. The estimates of genetic correlations were very high (range 0.77–0.99), indicating that genetic factors that influence the expression of the different dimensions of PWB may be shared to a large extent. Non-shared environmental correlations ranged from substantial to high, with the exception of the correlation between autonomy and the dimensions of purpose in life, self-acceptance and personal growth.

This study presents a twin analysis of PWB measured by the SPWB dimensions; it was found that both genes and non-shared environment play a role in individual differences. The genetic and non-shared environmental correlations between SPWB dimensions suggest that common underlying genetic and non-shared environmental factors influence the expression of the different facets of PWB.

Obesity is characterized by chronic low-grade inflammation that may lead to emotional distress and behavioural symptoms. This study assessed the relationship between adiposity, low-grade inflammation, eating behaviour and emotional status in obese women awaiting gastric surgery and investigated the effects of surgery-induced weight loss on this relationship.

A total of 101 women with severe or morbid obesity awaiting gastric surgery were recruited. Assessments were performed before and at 1 year post-surgery and included the measurement of neuroticism and extraversion using the revised Neuroticism–Extraversion–Openness personality inventory (NEO-PI-R) and eating behaviour using the Three-Factor Eating Questionnaire (TFEQ). Blood samples were collected for the measurement of serum inflammatory markers [interleukin-6 (IL-6), high-sensitive C-reactive protein (hsCRP)] and adipokines (leptin, adiponectin).

At baseline, body mass index (BMI) was positively correlated with inflammatory markers and adipokines. Regression analyses adjusting for age and diabetes revealed that baseline concentrations of IL-6 and hsCRP were associated with the depression and anxiety facets of neuroticism, with higher inflammation predicting higher anxiety and depression. This association remained significant after adjusting for BMI. Gastric surgery induced significant weight loss, which correlated with reduced inflammation. After controlling for BMI variations, decreases in inflammatory markers, notably hsCRP, were associated with reduced anxiety and TFEQ-cognitive restraint scores.

These findings indicate strong associations between adiposity, inflammation and affectivity in obese subjects and show that surgery-induced weight loss is associated concomitantly with reduced inflammation and adipokines and with significant improvement in emotional status and eating behaviour. Inflammatory status appears to represent an important mediator of emotional distress and psychological characteristics of obese individuals.

Psychiatric co-morbidity is complex and ubiquitous. Our aim was to describe the extent, nature and patterning of psychiatric co-morbidity within a representative sample of the adult population of England, using latent class analysis.

Data were used from the 2007 Adult Psychiatric Morbidity Survey, a two-phase national household survey undertaken in 2007 comprising 7325 participants aged 16 years and older living in private households in England. The presence of 15 common mental health and behavioural problems was ascertained using standardized clinical and validated self-report measures, including three anxiety disorders, depressive episode, mixed anxiety depressive disorder, psychosis, antisocial and borderline personality disorders, eating disorders, post-traumatic stress disorder, attention deficit disorder, alcohol and drug dependencies, problem gambling and attempted suicide.

A four-class model provided the most parsimonious and informative explanation of the data. Most participants (81.6%) were assigned to a non-symptomatic or ‘Unaffected’ class. The remainder were classified into three qualitatively different symptomatic classes: ‘Co-thymia’ (12.4%), ‘Highly Co-morbid’ (5.0%) and ‘Addictions’ (1.0%). Classes differed in mean numbers of conditions and impairments in social functioning, and these dimensions were correlated.

Our findings confirm that mental disorders typically co-occur and are concentrated in a relatively small number of individuals. Conditions associated with the highest levels of disability, mortality and cost – psychosis, suicidality and personality disorders – are often co-morbid with more common conditions. This needs to be recognized when planning services and when considering aetiology.