Research question | Main findings | Directions for future research |
---|---|---|
1. TAND research across years | The number of TAND studies has increased over time, particularly since the term TAND was coined | Systematic reviews of each cluster should be conducted to capture TAND research that may have been missed |
2. TAND research location | TAND research is predominantly conducted in HICs, the majority of HIC-led TAND research occurs in the USA and the UK | More research is needed particularly in South American, Middle Eastern, African, South-East Asia and Western Pacific countries |
TAND research is only evident in some LMICs due to representation from larger HIC-led multisite studies (e.g. Argentina, Mexico, Romania) | More TAND-focused research is needed that originates from LMICs reflecting specific cultural contexts, as opposed to research that only includes LMICs as part of larger multisite studies | |
3. Age distribution | The majority of human TAND research involves school-age and adolescent samples, with fewer studies including infant (0–3 years) or older adult samples (60 years and over) | Research that specifically focuses on the presentation of TAND across the lifespan and longitudinal research that investigates changes in TAND across developmental stages are needed |
4. Study quality | Most case and cohort studies provide epilepsy and intellectual ability information but TSC genetic confirmation in studies is relatively low | TAND researchers should be encouraged to include data on seizures, intellectual ability and TSC genotype where possible |
The majority of TAND cohort studies involve fewer than 50 participants | Large-scale, coordinated cohort studies involving multisite international collaboration should be considered, except where specific research questions warrant small samples | |
Animal studies and case studies are rated as high or relatively high quality; however, there is considerable variability in the quality of cohort studies, perhaps as a consequence of the quality appraisal tool used | Development of a scoping review quality appraisal tool will be beneficial to aid in the interpretation of study quality that allows for cross-comparison between different study designs | |
5. TAND levels | Animal studies largely report on the behavioural level of TAND | More contemporary animal research is needed that explores the neuropsychological level of TAND |
Case studies and cohort studies largely report on behavioural and intellectual TAND levels | In human studies, research is needed that focuses on the academic, neuropsychological and psychosocial levels of TAND | |
6. Research methods and measures | Animal studies utilise behavioural protocols and neuroimaging techniques | More TSC animal model research is needed that specifically utilises behavioural protocols that are relevant to TAND |
Case studies largely employ medical record reviews neuroimaging and physiological examinations, but rarely utilise standardised research assessments | TAND case studies would benefit from the inclusion of standardised assessments where possible and description of assessments completed as part of a clinical evaluation | |
Cohort studies utilise IQ assessments and diagnostic research measures of autism | More direct behavioural assessments and behavioural observations in TAND research is needed, as well as a need to outline which specific diagnostic measures have been utilised when reporting TAND information based on psychological evaluation | |
As a recently published measure, the TAND Checklist is rarely used as an assessment tool in human research | Human studies would benefit from the inclusion of TAND Checklist reporting where applicable | |
7. Quantitative and qualitative research | There are relatively few qualitative cohort studies | Qualitative research will be useful to refine the phenomenology of TAND behaviours that are not well-characterised in the existing literature |
The few qualitative studies that exist largely explore the psychosocial level | More qualititative research is needed that explores the under-researched areas of TAND | |
The majority of quantitative cohort studies are descriptive as they do not utilise contrast or control groups | TAND cohort studies would benefit from the utilisation of appropriate control and contrast groups to determine TSC-specific manifestations of behaviours | |
8. Interventions | There are very few published intervention cohort studies, with a notable absence of any non-pharmacological intervention studies | Intervention studies are needed that take into account TAND outcomes, particularly exploring the effectiveness of non-pharamacological interventions in relation to TAND |
9. Remote technologies | Only a small minority of cohort studies have employed remote methods of data collection, those that do largely explore the psychosocial level | Studies utilising remote technologies (e.g. mobile applications, video conferencing, online surveys) may help address TAND knowledge gaps and increase LMIC and population-based research |
10. TAND clusters | A number of TAND clusters are under-researched in animal studies | More TSC animal models are needed that explore the dysregulated behaviour, overactive/impulsive and eat/sleep clusters |
Across human studies, the scholastic cluster is relatively under-researched | TAND clusters that are under-researched may be difficult to assess or quantify, and efforts should be made to evaluate existing assessments and tools to determine their utility in TSC cohorts | |
The autism spectrum disorder–like cluster is the most widely researched across all three study types | Human studies would benefit from TAND-specific research that explores under-researched clusters, specifically the scholastic and eat/sleep clusters in TSC cohorts |