Validity of the Mood Disorder Questionnaire (MDQ) as a screening tool for bipolar spectrum disorders in anabaptist populations

Strong Genetic Overlaps Between Dimensional and Categorical Models of Bipolar Disorders in a Family Sample

Background

Bipolar disorder (BD) presents with a wide range of symptoms that vary among relatives, casting doubt on categorical illness models. To address this uncertainly, we investigated the heritability and genetic relationships between categorical and dimensional models of BD in a family sample.

Methods

Participants in the Amish-Mennonite Bipolar Genetics (AMBiGen) study were assigned categorical mood disorder diagnoses by structured psychiatric interview and completed the Mood Disorder Questionnaire (MDQ), which assesses lifetime history of manic symptoms and associated impairment. Major MDQ dimensions were analyzed by Principal Component Analysis (PCA) in 726 participants. Heritability and genetic overlaps between categorical diagnoses and MDQ-derived dimensions were estimated with SOLAR-ECLIPSE within 432 genotyped participants.

Results

MDQ scores were significantly higher among individuals diagnosed with BD and related disorders, as expected, but varied widely among relatives. PCA suggested a three-component model for the MDQ. Heritability of the MDQ score was 30% (p<0.001), evenly distributed across its three principal components. Strong and significant genetic correlations were found between categorical diagnoses and most MDQ measures.

Limitations

Recruitment through probands with BD resulted in increased prevalence of BD in this sample, limiting generalizability. Unavailable genetic data reduced sample size for some analyses.

Conclusion

heritability and high genetic correlations between categorical diagnoses and MDQ measures support a genetic continuity between dimensional and categorical models of BD.

Dimensions of psychopathology associated with psychotic-like experiences: Findings from the network analysis in a nonclinical sample

BACKGROUND

Psychotic-like experiences (PLEs) are associated with a variety of psychopathological symptoms. However, it remains unknown which dimensions of psychopathology are most closely related to the occurrence of PLEs. In this study, we aimed to analyze the association of PLEs with various domains of psychopathology.

METHODS

A total of 1100 nonclinical adults (aged 18-35 years, 51.4% females) with a negative history of psychiatric treatment were surveyed. Assessment of psychopathology was performed using self-reports. Symptoms associated with PLEs were explored as continuous variables and based on clinically relevant thresholds using two separate network analyses.

RESULTS

In both network analyses, PLEs were directly connected to obsessive-compulsive disorder (OCD) symptoms, manic symptoms, depressive symptoms, and attention-deficit/hyperactivity disorder (ADHD) symptoms. Anxiety symptoms were associated with PLEs only in the network based on threshold scores. Importantly, edge weight for the connection of PLEs and OCD symptoms was significantly higher compared to edge weights of all other direct connections of PLEs with psychopathology in both networks. Edge weight for the connection between PLEs and manic symptoms was significantly higher compared to edge weights for direct connections of PLEs with depressive and ADHD symptoms in the network based on continuous scores of psychopathological symptoms. Edge weights of direct connections of PLEs with depressive, anxiety, and ADHD symptoms did not differ significantly in both networks.

CONCLUSIONS

Our findings indicate that PLEs are associated with multiple domains of psychopathology. However, these phenomena are most strongly associated with OCD symptoms regardless of their severity threshold.

Psychotic-like experiences as a co-occurring psychopathological indicator of multi-dimensional affective symptoms: Findings from a cross-sectional survey among college students

BACKGROUND

Although connections between psychotic-like experiences (PLEs) and a series of non-psychotic disorders have been widely explored in previous research, it is unclear whether PLEs could act as a co-occurring psychopathological indicator of multi-dimensional affective symptoms.

METHODS

A total of 4761 students took part in an online survey which assessed the frequency of PLEs and three types of affective symptoms over lifetime. Binary logistic regression models were used to examine associations between PLEs and each type of affective symptom. Network analysis was conducted to explore the relationship among three subtypes of PLEs - persecutory ideation (PI), bizarre experiences (BEs) and perceptual abnormalities (PAs), and different types of affective symptoms.

RESULTS

The results showed that compared with the non-PLEs group, the PLEs group suffered significantly higher risk of experiencing three types of affective symptoms, including manic symptoms [adjusted odds ratio (aOR) 11.50, 95 % confidence interval (CI) (4.59-28.81)], depressive symptoms [aOR 7.28, 95 % CI (4.98-10.66)] and anxiety symptoms [aOR 4.47, 95 % CI (3.10-6.43)]. In the network model, bizarre experiences were the most critical central symptom. Both depressive and anxiety symptoms were most strongly associated with persecutory ideation while manic symptoms were most closely related to bizarre experiences.

LIMITATIONS

Cross-sectional data and self-reported symptoms.

CONCLUSIONS

These findings suggest that PLEs are a vital co-occurring indicator of multi-dimensional affective symptoms and show its enormous potential as a target for a host of mental health problems. Further investigation may shed light on the aetiology of the relationship between different subtypes of PLEs and affective symptoms.