Dearbhla Connor

Prevalence of psychotic symptoms in childhood and adolescence: a systematic review and meta-analysis of population-based studies.

BACKGROUND Psychotic symptoms occur more frequently in the general population than psychotic disorder and index risk for psychopathology. Multiple studies have reported on the prevalence of these symptoms using self-report questionnaires or clinical interviews but there is a lack of consensus about the prevalence of psychotic symptoms among children and adolescents. METHOD We conducted a systematic review of all published literature on psychotic symptom prevalence in two age groups, children aged 9-12 years and adolescents aged 13-18 years, searching through electronic databases PubMed, Ovid Medline, PsycINFO and EMBASE up to June 2011, and extracted prevalence rates. RESULTS We identified 19 population studies that reported on psychotic symptom prevalence among children and adolescents. The median prevalence of psychotic symptoms was 17% among children aged 9-12 years and 7.5% among adolescents aged 13-18 years. CONCLUSIONS Psychotic symptoms are relatively common in young people, especially in childhood. Prevalence is higher in younger (9-12 years) compared to older (13-18 years) children.

Cannabis use and childhood trauma interact additively to increase the risk of psychotic symptoms in adolescence.

BACKGROUND Adolescent cannabis use has been shown in many studies to increase the risk of later psychosis. Childhood trauma is associated with both substance misuse and risk for psychosis. In this study our aim was to investigate whether there is a significant interaction between cannabis use and childhood trauma in increasing the risk for experiencing psychotic symptoms during adolescence. METHOD Psychiatric interviews using the Schedule for Affective Disorders and Schizophrenia for School-Age Children (K-SADS) semi-structured instrument were carried out with 211 adolescents aged between 12 and 15 years and their parents as part of a population-based study. The interview enquired about early traumatic events, cannabis use and psychiatric symptoms in adolescence. RESULTS In separate analyses both cannabis use and childhood trauma were significantly associated with risk of experiencing psychotic symptoms. However, the presence of both childhood trauma and early cannabis use significantly increased the risk for psychotic symptoms beyond the risk posed by either risk factor alone, indicating that there was a greater than additive interaction between childhood trauma and cannabis use. CONCLUSION Our finding of a greater than additive interaction between childhood trauma and cannabis use may have implications for the identification of individuals at high risk of experiencing psychotic symptoms. For example, measures to actively discourage or intensively treat cannabis use in children and adolescents who have experienced abuse may help to prevent the development of psychosis in this vulnerable group. Our findings require replication in larger samples to confirm this interaction effect.

The prevalence of psychosis in epilepsy; a systematic review and meta-analysis

BackgroundEpilepsy has long been considered to be a risk factor for psychosis. However there is a lack of consistency in findings across studies on the effect size of this risk which reflects methodological differences in studies and changing diagnostic classifications within neurology and psychiatry. The aim of this study was to assess the prevalence of psychosis in epilepsy and to estimate the risk of psychosis among individuals with epilepsy compared with controls.MethodsA systematic review and meta-analysis was conducted of all published literature pertaining to prevalence rates of psychosis in epilepsy using electronic databases PUBMED, OVIDMEDLINE, PsychINFO and Embase from their inception until September 2010 with the following search terms: prevalence, incidence, rate, rates, psychosis, schizophrenia, schizophreniform illness, epilepsy, seizures, temporal lobe epilepsy.ResultsThe literature search and search of reference lists yielded 215 papers. Of these, 58 (27%) had data relevant to the review and 157 were excluded following a more detailed assessment. 10% of the included studies were population based studies. The pooled odds ratio for risk of psychosis among people with epilepsy compared with controls was 7.8. The pooled estimate of prevalence of psychosis in epilepsy was found to be 5.6% (95% CI: 4.8-6.4). There was a high level of heterogeneity. The prevalence of psychosis in temporal lobe epilepsy was 7% (95% CI: 4.9-9.1). The prevalence of interictal psychosis in epilepsy was 5.2% (95% CI: 3.3-7.2). The prevalence of postictal psychosis in epilepsy was 2% (95% CI: 1.2-2.8).ConclusionsOur systematic review found that up to 6% of individuals with epilepsy have a co-morbid psychotic illness and that patients have an almost eight fold increased risk of psychosis. The prevalence rate of psychosis is higher in temporal lobe epilepsy (7%). We suggest that further investigation of this association could give clues to the aetiology of psychosis.

Relationship between the COMT-Val158Met and BDNF- Val66Met Polymorphisms, Childhood Trauma and Psychotic Experiences in an Adolescent General Population Sample

Objective Psychotic experiences occur at a much greater prevalence in the population than psychotic disorders. There has been little research to date, however, on genetic risk for this extended psychosis phenotype. We examined whether COMT or BDNF genotypes were associated with psychotic experiences or interacted with childhood trauma in predicting psychotic experiences. Method Psychiatric interviews and genotyping for COMT-Val158Met and BDNF-Val66Met were carried out on two population-based samples of 237 individuals aged 11-15 years. Logistic regression was used to examine for main effects by genotype and childhood trauma, controlling for important covariates. This was then compared to a model with a term for interaction between genotype and childhood trauma. Where a possible interaction was detected, this was further explored in stratified analyses. Results While childhood trauma showed a borderline association with psychotic experiences, COMT-Val158Met and BDNF-Val66Met genotypes were not directly associated with psychotic experiences in the population. Testing for gene x environment interaction was borderline significant in the case of COMT-Val158Met with individuals with the COMT-Val158Met Val-Val genotype, who had been exposed to childhood trauma borderline significantly more likely to report psychotic experiences than those with Val-Met or Met-Met genotypes. There was no similar interaction by BDNF-Val66Met genotype. Conclusion The COMT-Val158Met Val-Val genotype may be a genetic moderator of risk for psychotic experiences in individuals exposed to childhood traumatic experiences.

The impact of adolescent cannabis use, mood disorder and lack of education on attempted suicide in young adulthood

Suicide is one of the leading causes of death worldwide among young people. One of the strongest predictors of completed suicide is a previous suicide attempt (1). Suicide attempts are more frequent among young people, and a suicide attempt may be a marker of a lasting trajectory of adverse mental and physical problems into middle adulthood (1,2).There is limited evidence for factors during the adolescent period and the period of transition to young adulthood that increase the risk of attempted suicide. We used a prospective cohort study design incorporating clinical interviews to determine what factors measured at ages 12-15 years are associated with attempted suicide reported at ages 19-24 years. The methods for the baseline adolescent study have previously been described (3). Using a stratified random sampling technique, 743 students in eight mainstream schools were screened for psychopathology. Adolescents who scored above threshold on the screening instruments or who indicated the presence of significant suicidal ideation (N=140) were invited to attend for interview, along with a group of 174 controls matched for gender, school and school year. 84.3% adolescents from the “at risk” category and 54% of the control group attended for a semi-structured clinical interview, along with a parent or guardian. All 212 young people who were interviewed as young adolescents were invited to take part in a follow-up interview eight years later. Follow-up information was obtained on 168 participants (79% follow-up rate). There were no differences between responders and non-responders in age, gender, parental socio-economic status, “at-risk” status at baseline, or diagnosis of psychiatric disorder at baseline. We collected exposure information at interview on: family and childhood risk factors (family history of psychiatric illness and experience of childhood trauma, i.e. physical/sexual abuse or witnessing domestic violence); adolescent risk factors (psychopathology, cannabis use and alcohol use); young adult risk factors (psychopathology, cannabis use, self-harm, education level and employment status). The outcome measure was lifetime suicide attempts at 19-24 years old. Ten percent of participants had made a suicide attempt at some point in their lives up to age 19-24 years. The mean age of those attempting suicide was 20.6 years. Fifty-three percent of those who reported a suicide attempt were female. Hierarchical logistic regression models showed that adolescent mood disorder and adolescent cannabis use, young adult mood and anxiety disorders, and a low level of education were the most strongly predictive factors for making a suicide attempt when the effects of family psychiatric history, childhood trauma, alcohol use and other psychopathology were taken into account. Adolescent mood disorder and adolescent cannabis use both independently increased the odds of a suicide attempt 7-fold (OR=7.0, 95% CI: 1.4-34.3; OR=7.5, 95% CI: 1.2-43.8), while young adult mood and anxiety disorders both independently increased the odds of an attempt 11-fold (OR=11.7, 95% CI 1.8-73.9; OR=11.1, 95% CI: 21.0-57.9). Young adults with only secondary-level education had an 8-fold increase in the odds of a suicide attempt compared to those with third-level education (OR=8.0, 95% CI: 1.1-54.4). There is evidence that substance use disorders in adulthood increase the risk of suicidal behaviours. Here we show that any use of cannabis in the early adolescent period is a strong independent predictor of attempted suicide in young adulthood. We know that significant brain maturation continues to occur during adolescence, particularly in limbic structures such as the hippocampus; and within the prefrontal cortex important processes such as synaptic pruning, myelination and programming of neurotrophic levels are occurring at this time (4). Regular cannabis use can lead to grey matter volume reduction in a range of brain areas, including the medial temporal cortex, the parahippocampal gyrus, the insula and orbitofrontal regions (5). There is evidence of a linear association between the age at onset of cannabis use and both white matter integrity and grey matter volume, suggesting that the earlier the onset of use, the greater the toxic effects on the brain (5,6). Neuroimaging studies of people who have attempted suicide show structural and functional brain changes that are in keeping with those found in cannabis users (7). It is possible that cannabis use in early adolescence, at a vulnerable time for neurodevelopment, leads to or exacerbates ongoing dysfunctional brain changes that prime young people for a maladaptive trajectory towards young adulthood. Those most at risk for attempted suicide may have experienced accumulating risk exposures throughout childhood and adolescence and in young adulthood may lack adequate problem solving skills, as possibly indexed here by low levels of education. The increasing awareness among the mental health community that we need to focus on early clinical intervention to protect against the worst effects of emotional distress among our young people, both on a personal and an economic level (8), can only be acted on when we can reliably identify which young people are most at risk. The available evidence suggests that the specialist treatment of psychiatric disorder in adolescence alone is insufficient for the prevention of future suicide attempts (9). We need a more tailored approach to youth mental health and a greater awareness of the different contingencies involved in the pathway to suicidal behaviours such as accumulating risk from adolescent cannabis use, adolescent mood disorders and a lack of education.

The association between economic inactivity and mental health among young people: a longitudinal study of young adults who are not in employment, education or training

OBJECTIVES Increasing rates of young people not in education, employment or training (NEETs) are a cause of concern both in Ireland and internationally, but little longitudinal research has examined the link between psychiatric disorder in young people and NEET status. METHODS The Challenging Times (CT) Study is a longitudinal, population-based study of psychopathology among 212 young Irish people. Clinical interviews were performed at two time points: 12-15 years and 19-24 years. RESULTS NEET status in young adulthood was associated with a sevenfold increased risk of current suicidal ideation. This result was independent of prior adolescent mental disorder. NEET young people had a fourfold increased odds of being diagnosed with a mental disorder in childhood or early adolescence compared with their economically active peers. NEET young people were at an almost threefold increased risk of any mental health disorder a twofold increased risk of anxiety disorder and threefold increased odds of suicide attempts over their lifetime compared with economically active peers. CONCLUSIONS NEET young people are at increased risk for mental disorder and suicidal ideation. The association is bidirectional, as prior mental disorder in adolescence appeared to account for much of the association between NEET status and current mental health problems. However, economic inactivity conveys an increased risk for suicidal ideation over and above that due to prior disorder. Our findings provide a compelling economic and societal argument for early intervention and treatment of mental disorder and the importance of vocational interventions for reducing suicide risk in young adults.

Nonsuicidal self-injury, suicidal thoughts and suicide attempts among sexual minority youth in Ireland during their emerging adult years

This study aimed to examine whether or not sexual minority youth constitute an at‐risk group for nonsuicidal self‐injury, suicidal ideation or suicide attempts during their emerging adult years.