To estimate the conversion rate from unipolar depression (ICD10 codes F32-F33) to bipolar disorde... more To estimate the conversion rate from unipolar depression (ICD10 codes F32-F33) to bipolar disorder (BP) (ICD10 codes F31) in an English national cohort. It was hypothesised that early-onset BP (age <18 years) is a more severe form of the disorder, with a more rapid, and higher rate of conversion from depression to BP. This record linkage study used English national Hospital Episode Statistics (HES) covering all NHS inpatient and day case admissions between 1999 and 2011. The overall rate of conversion from depression to BP for all ages was 5.65% (95% CI: 5.48-5.83) over a minimum 4-year follow-up period. The conversion rate from depression to BP increased in a linear manner with age from 10-14 years - 2.21% (95% C: 1.16-4.22) to 30-34 years - 7.06% (95% CI: 6.44-7.55) (F1,23=77.6, p=0.001, R(2)=0.77). The time to conversion was constant across the age range. The rate of conversion was higher in females (6.77%; 95% CI: 6.53-7.02) compared to males, (4.17%; 95% CI: 3.95-4.40) (χ(2)=194, p<0.0001), and in those with psychotic depression 8.12% (95% CI: 7.65-8.62) compared to non-psychotic depression 5.65% (95% CI: 5.48-5.83) (χ(2)=97.0, p<0.0001). The study was limited to hospital discharges and diagnoses were not standardised. Increasing conversion rate from depression to bipolar disorder with age, and constant time for conversion across the age range does not support the notion that early-onset BP is a more severe form of the disorder.
Journal of the Canadian Academy of Child and Adolescent Psychiatry = Journal de l'Académie canadienne de psychiatrie de l'enfant et de l'adolescent, 2012
Journal of the Canadian Academy of Child and Adolescent Psychiatry = Journal de l'Académie canadienne de psychiatrie de l'enfant et de l'adolescent, 2013
The focus of this paper is to explore how a developmental perspective can advance understanding o... more The focus of this paper is to explore how a developmental perspective can advance understanding of the clinical trajectory into bipolar disorder (BD) and clarify controversies regarding the diagnosis in youth. In this selective review, we focus on findings from longitudinal studies of general population and high-risk pediatric cohorts in order to inform our understanding of the development of BD in youth. Also highlighted are related aspects of the debate about the diagnosis in young children and a discussion of the implications of the findings for advancing early detection and intervention clinical and research efforts. Evidence overwhelmingly suggests that BD typically onsets in adolescence and early adulthood, with the depressive polarity of the illness dominating the early course. Non-specific childhood antecedents have been noted in some high-risk individuals. However, in youth without a confirmed familial risk of BD, manic-like symptoms have little prognostic significance for ...
The author reviewed prospective longitudinal studies of the offspring of parents with bipolar dis... more The author reviewed prospective longitudinal studies of the offspring of parents with bipolar disorder to inform our understanding of the nature of the association between childhood ADHD and the risk of developing bipolar disorder in adolescence and young adulthood. A literature review of published prospective cohort studies of the offspring of bipolar parents since 1985 was undertaken using a comprehensive search strategy in several electronic databases. The author provides a qualitative synthesis of results focusing on ADHD and the association with bipolar disorder in prospectively assessed high-risk offspring. These results are discussed in light of findings from other prospective epidemiological and clinical cohort studies. From the reviewed high-risk studies, evidence suggests that the clinical diagnosis of childhood ADHD is not a reliable predictor of the development of bipolar disorder. However, the author found evidence that symptoms of inattention may be part of a mixed clinical presentation during the early stages of evolving bipolar disorder in high-risk offspring, appearing alongside anxiety and depressive symptoms. The author also found preliminary evidence that childhood ADHD may form part of a neurodevelopmental phenotype in offspring at risk for developing a subtype of bipolar disorder unresponsive to lithium stabilization. While childhood ADHD does not appear to be part of the typical developmental illness trajectory of bipolar disorder, subjective problems with attention can form part of the early course, while neurodevelopmental abnormalities may be antecedents in a subgroup of high-risk children.
Journal of the Canadian Academy of Child and Adolescent Psychiatry Journal De L Academie Canadienne De Psychiatrie De L Enfant Et De L Adolescent, Aug 1, 2009
There has been substantial clinical and research interest in describing the complete natural hist... more There has been substantial clinical and research interest in describing the complete natural history of bipolar disorder, and related to this significant debate in regard to the validity of the bipolar diagnosis in very young children. Given the high heritability of bipolar disorder, longitudinal high risk studies can provide important information in regard to the evolution of the disorder. A selected review and discussion of the findings from key longitudinal high risk studies are presented focusing on the relevance for mapping the early course of illness, addressing the validity of the bipolar diagnosis in very young referred children and implications for diagnosis and organization of services. To date, there have been findings reported from several longitudinal high risks studies starting with well characterized affected parents, all of which support an evolution of psychopathology from non-specific disorders to frank bipolarity. Early childhood antecedents include internalizing and sleep disorders and typically not behavioural disorders. In the majority of cases, the early mood pathology and associated morbidity is related to the depressive polarity. None of these studies have reported a single case of pre-pubertal mania. These findings highlight the importance of considering the clinical course and the family history in diagnostic formulation in pediatric patients early in the course of a psychiatric illness. The implications of these findings for early intervention and organization of child psychiatry services are discussed.
This study explored the nature of the association between bipolar disorder and alcoholism. The au... more This study explored the nature of the association between bipolar disorder and alcoholism. The authors studied 814 first-degree relatives of 121 bipolar patients, divided on the basis of response to lithium prophylaxis. Logistic regression analysis was used to analyze the contribution of demographic, familial and clinical variables to the risk of primary alcoholism in the relatives. The risk of primary alcoholism in relatives was not related to the degree of affective loading in the family or to the proband's lithium response. This study does not support a shared genetic liability between bipolar disorder and alcoholism. This study lacked a control group, but the analysis accounted for this. These disorders are not alternative forms of the same illness.
Exposure to postnatal parental depression is associated with offspring mood disorder later in lif... more Exposure to postnatal parental depression is associated with offspring mood disorder later in life; however, little is known about exposure to parental bipolar disorder (BD) and subsequent risk of psychopathology. The aim of this study was to determine the association between the duration, severity and timing of exposure to parental BD in early childhood and subsequent risk of mood disorder. 189 offspring of a parent with BD completed annual assessments following Kiddie Schedule for Affective Disorders (KSADS) format semistructured interviews as part of an ongoing 16-year prospective cohort study. Clinical data from the affected parents were collected over the first decade of their offspring's life using SADS-L format semistructured interviews and coded using the Affective Morbidity Index (AMI). A longer duration of exposure to parental BD was associated with a 1.5-fold risk of any psychopathology (95% confidence interval (CI): 1.0-2.3) and a 2.5-fold increased risk of substance...
To estimate the conversion rate from unipolar depression (ICD10 codes F32-F33) to bipolar disorde... more To estimate the conversion rate from unipolar depression (ICD10 codes F32-F33) to bipolar disorder (BP) (ICD10 codes F31) in an English national cohort. It was hypothesised that early-onset BP (age <18 years) is a more severe form of the disorder, with a more rapid, and higher rate of conversion from depression to BP. This record linkage study used English national Hospital Episode Statistics (HES) covering all NHS inpatient and day case admissions between 1999 and 2011. The overall rate of conversion from depression to BP for all ages was 5.65% (95% CI: 5.48-5.83) over a minimum 4-year follow-up period. The conversion rate from depression to BP increased in a linear manner with age from 10-14 years - 2.21% (95% C: 1.16-4.22) to 30-34 years - 7.06% (95% CI: 6.44-7.55) (F1,23=77.6, p=0.001, R(2)=0.77). The time to conversion was constant across the age range. The rate of conversion was higher in females (6.77%; 95% CI: 6.53-7.02) compared to males, (4.17%; 95% CI: 3.95-4.40) (χ(2)=194, p<0.0001), and in those with psychotic depression 8.12% (95% CI: 7.65-8.62) compared to non-psychotic depression 5.65% (95% CI: 5.48-5.83) (χ(2)=97.0, p<0.0001). The study was limited to hospital discharges and diagnoses were not standardised. Increasing conversion rate from depression to bipolar disorder with age, and constant time for conversion across the age range does not support the notion that early-onset BP is a more severe form of the disorder.
Journal of the Canadian Academy of Child and Adolescent Psychiatry = Journal de l'Académie canadienne de psychiatrie de l'enfant et de l'adolescent, 2012
Journal of the Canadian Academy of Child and Adolescent Psychiatry = Journal de l'Académie canadienne de psychiatrie de l'enfant et de l'adolescent, 2013
The focus of this paper is to explore how a developmental perspective can advance understanding o... more The focus of this paper is to explore how a developmental perspective can advance understanding of the clinical trajectory into bipolar disorder (BD) and clarify controversies regarding the diagnosis in youth. In this selective review, we focus on findings from longitudinal studies of general population and high-risk pediatric cohorts in order to inform our understanding of the development of BD in youth. Also highlighted are related aspects of the debate about the diagnosis in young children and a discussion of the implications of the findings for advancing early detection and intervention clinical and research efforts. Evidence overwhelmingly suggests that BD typically onsets in adolescence and early adulthood, with the depressive polarity of the illness dominating the early course. Non-specific childhood antecedents have been noted in some high-risk individuals. However, in youth without a confirmed familial risk of BD, manic-like symptoms have little prognostic significance for ...
The author reviewed prospective longitudinal studies of the offspring of parents with bipolar dis... more The author reviewed prospective longitudinal studies of the offspring of parents with bipolar disorder to inform our understanding of the nature of the association between childhood ADHD and the risk of developing bipolar disorder in adolescence and young adulthood. A literature review of published prospective cohort studies of the offspring of bipolar parents since 1985 was undertaken using a comprehensive search strategy in several electronic databases. The author provides a qualitative synthesis of results focusing on ADHD and the association with bipolar disorder in prospectively assessed high-risk offspring. These results are discussed in light of findings from other prospective epidemiological and clinical cohort studies. From the reviewed high-risk studies, evidence suggests that the clinical diagnosis of childhood ADHD is not a reliable predictor of the development of bipolar disorder. However, the author found evidence that symptoms of inattention may be part of a mixed clinical presentation during the early stages of evolving bipolar disorder in high-risk offspring, appearing alongside anxiety and depressive symptoms. The author also found preliminary evidence that childhood ADHD may form part of a neurodevelopmental phenotype in offspring at risk for developing a subtype of bipolar disorder unresponsive to lithium stabilization. While childhood ADHD does not appear to be part of the typical developmental illness trajectory of bipolar disorder, subjective problems with attention can form part of the early course, while neurodevelopmental abnormalities may be antecedents in a subgroup of high-risk children.
Journal of the Canadian Academy of Child and Adolescent Psychiatry Journal De L Academie Canadienne De Psychiatrie De L Enfant Et De L Adolescent, Aug 1, 2009
There has been substantial clinical and research interest in describing the complete natural hist... more There has been substantial clinical and research interest in describing the complete natural history of bipolar disorder, and related to this significant debate in regard to the validity of the bipolar diagnosis in very young children. Given the high heritability of bipolar disorder, longitudinal high risk studies can provide important information in regard to the evolution of the disorder. A selected review and discussion of the findings from key longitudinal high risk studies are presented focusing on the relevance for mapping the early course of illness, addressing the validity of the bipolar diagnosis in very young referred children and implications for diagnosis and organization of services. To date, there have been findings reported from several longitudinal high risks studies starting with well characterized affected parents, all of which support an evolution of psychopathology from non-specific disorders to frank bipolarity. Early childhood antecedents include internalizing and sleep disorders and typically not behavioural disorders. In the majority of cases, the early mood pathology and associated morbidity is related to the depressive polarity. None of these studies have reported a single case of pre-pubertal mania. These findings highlight the importance of considering the clinical course and the family history in diagnostic formulation in pediatric patients early in the course of a psychiatric illness. The implications of these findings for early intervention and organization of child psychiatry services are discussed.
This study explored the nature of the association between bipolar disorder and alcoholism. The au... more This study explored the nature of the association between bipolar disorder and alcoholism. The authors studied 814 first-degree relatives of 121 bipolar patients, divided on the basis of response to lithium prophylaxis. Logistic regression analysis was used to analyze the contribution of demographic, familial and clinical variables to the risk of primary alcoholism in the relatives. The risk of primary alcoholism in relatives was not related to the degree of affective loading in the family or to the proband's lithium response. This study does not support a shared genetic liability between bipolar disorder and alcoholism. This study lacked a control group, but the analysis accounted for this. These disorders are not alternative forms of the same illness.
Exposure to postnatal parental depression is associated with offspring mood disorder later in lif... more Exposure to postnatal parental depression is associated with offspring mood disorder later in life; however, little is known about exposure to parental bipolar disorder (BD) and subsequent risk of psychopathology. The aim of this study was to determine the association between the duration, severity and timing of exposure to parental BD in early childhood and subsequent risk of mood disorder. 189 offspring of a parent with BD completed annual assessments following Kiddie Schedule for Affective Disorders (KSADS) format semistructured interviews as part of an ongoing 16-year prospective cohort study. Clinical data from the affected parents were collected over the first decade of their offspring's life using SADS-L format semistructured interviews and coded using the Affective Morbidity Index (AMI). A longer duration of exposure to parental BD was associated with a 1.5-fold risk of any psychopathology (95% confidence interval (CI): 1.0-2.3) and a 2.5-fold increased risk of substance...
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Papers by Anne Duffy