Bias in psychopathology research

'Something wasn't quite right': a novel phenomenological analysis of internet discussion posts detailing initial awareness of psychosis

INTRODUCTION

A significant number of psychosis studies have focussed on and have attempted to model and frame the earliest psychosis experiences. Using a wide array of methodologies and targeting a variety of 'at risk' groups, researchers have offered much to inform our treatment responses, and understanding of psychosis onset and development.

OBJECTIVES

Due to the nature of scientific investigation however and investigator led exploration, those who experience psychosis are rarely afforded ultimate free rein to dictate and direct the exchange of information or to impose their unique narrative on that which is being explored. In an attempt to address this, the current study opportunistically harvested rich self-report data from replies to the question, "People that have been diagnosed with schizophrenia, what was the first time you noticed something wasn't quite right?" on the internet discussion forum Reddit.com.

METHODS

User data was analysed using Interpretive Phenomenological Analysis to identify key themes in participants' first experiences and initial awareness of psychosis.

RESULTS

While respondents varied widely in their recounted experiences and chose to describe these experiences in a variety of ways, analysis showed that (i) respondent distress was associated with psychosis onset timeframe, negative-voice auditory hallucinations, visual hallucinations, paranoid delusions, and insight (ii) early childhood psychosis experience resulted in novel explanatory schemas and psychosis/distress progression with contributory factors in adolescence and (iii) 41.3% of the sample reported self-realisation in gaining insight and greater insight was associated with help-seeking behaviour.

CONCLUSIONS

This novel use of publicly shared experiential data might enrich our existing qualitative literature concerning early psychosis.

Incomplete coverage of candidate genes: a poorly considered bias

Current genetic investigations are performed both on the basis of a rational and biologically based choice of candidate genes and through genome wide scans. Nonetheless, lack of replication is a common problem in psychiatric genetics as well as in other genetic fields. There are a number of reasons for this inconsistency, among them a well known but poorly considered issue is gene coverage. The aim of the present paper is to focus on this well known and defectively deemed bias, especially when a candidate gene approach is chosen. The rational and the technical feasibility of this proposal are discussed as well as a survey of current investigations. The known consistent methodology to fix this bias is also discussed.

The prevalence of autism spectrum disorders: impact of diagnostic instrument and non-response bias

BACKGROUND

A large part of the variability in rates of autism spectrum disorders (ASD) across studies is non-aetiologic, and can be explained by differences in diagnostic criteria, case-finding method, and other issues of study design.

AIM

To investigate the effects on ASD prevalence of two methodological issues; non-response bias and case ascertainment. We compared the findings of using a semi-structured parent interview versus in-depth clinical assessment, including an ASD specific interview. We further explored whether including information on non-responders affected the ASD prevalence estimate.

METHOD

A total population of 7- to 9-year olds (N = 9,430) was screened for ASD with the autism spectrum screening questionnaire (ASSQ) in the Bergen Child Study (BCS). Children scoring above the 98th percentile on parent and/or teacher ASSQ were invited to participate in the second and subsequently in the third phase of the BCS where they were assessed for ASD using the Development and Well-Being Assessment (DAWBA), and the Diagnostic Interview for Social and Communication disorders (DISCO), respectively.

RESULTS

Clinical assessment using DISCO confirmed all DAWBA ASD cases, but also diagnosed additional cases. DISCO-generated minimum prevalence for ASD was 0.21%, whereas estimated prevalence was 0.72%, increasing to 0.87% when adjusting for non-responders. The DAWBA estimate for the same population was 0.44%.

CONCLUSION

Large variances in prevalence rates across studies can be explained by methodological differences. Both information about assessment method and non-response are crucial when interpreting prevalence rates of ASD.