Table 2 The ten core principles for the identification and treatment of TSC-associated neuropsychiatric disorders (TAND)

1. Everyone with TSC is at risk of TAND. Most people with TSC will have some TAND manifestations at some point in their lives. There are risk markers that increase the likelihood of TAND manifestations (such as the presence of intellectual disability, seizure disorders, a pathogenic variant in TSC2 vs TSC1). However, even without these risk markers, people can have TAND manifestations. Every person with TSC should therefore be considered as being at risk for TAND

2. Everyone with TSC needs lifelong monitoring for the emergence of TAND. Given that everyone is at risk of some TAND manifestations and given that TAND may present at various times throughout the lifespan, all people with TSC need lifelong monitoring for the emergence of TAND. Monitoring means screening at least annually to look for possible TAND manifestations in a systematic way. Tools like the TAND-L or TAND-SQ Checklists are well suited for regular screening and can be used by any professional who is supporting an individual who lives with TSC (TAND-L) or by families themselves (TAND-SQ)

3. Screen at least annually and follow up with appropriate action. Whenever screening picks up any concerns, this should be followed by appropriate action. Any concern about any TAND cluster difficulties should lead to an appropriate next step. Some of the next steps may be things to seek out (e.g., referral to a healthcare professional for diagnostic work-up and appropriate intervention based on the outcome of that evaluation). Other next steps may be things caregivers can do themselves (e.g., self-help tools or home-based interventions). All diagnoses and interventions should be provided by suitably qualified professionals. However, around the globe there are differences in which professional group does what. Screening should then be repeated at least once per year to make sure emerging difficulties are identified as soon as possible

4. The goal is early identification and early intervention. Given that all people with TSC are at risk of TAND, the goal is to identify TAND difficulties as early as possible and then to provide intervention as early as possible. Caregivers and clinicians are encouraged not to ‘watch and wait’ to see if things get better, but to act swiftly if there is concern

5. TAND clusters cluster together. It is very common for people with TSC to have difficulties in multiple clusters. If difficulties are identified in one TAND cluster, look for difficulties in other clusters. Co-occurring difficulties in TSC is the rule rather than the exception. Where cluster difficulties co-occur, it may be important to think how to prioritize and coordinate interventions

6. Always consider the impact of physical health problems and medications for physical health problems on TAND. Most people with TSC will have physical health difficulties such as skin, brain, kidney or other organ system involvement. These may play a very important role in relation to TAND manifestations. For instance, they may be the direct causes of a TAND difficulty (e.g., a growing Subependymal Giant Cell Astrocytoma, SEGA), or the medications used to treat the physical condition may cause TAND (e.g., antiseizure medications). Whenever anyone has TAND difficulties, consider the role of physical health problems and medications first. This is particularly important when sudden and unexpected change is seen in the TAND profile of a person with TSC

7. Work with families and caregivers as lived experts in TSC and TAND. Caregivers and people with TSC live with their difficulties every day. They are therefore the primary agents for the identification of TAND difficulties. They are also the most important partners in interventions for TAND. It is therefore of fundamental importance to strengthen and support families and to maintain a healthy partnership with family caregivers and individuals with TSC, recognizing their “lived expertise” with TSC and TAND. Some interventions should be provided by professionally qualified individuals. However, there are many evidence-based interventions that can be led by caregivers and families

8. Generate a “bio-psycho-social” “whole-system” plan for intervention. All TAND intervention plans should consider all the potential contributing factors such as biological (e.g., role of physical health, TSC medications, co-occurring diagnoses), psychological (e.g., family stress, life events, personality, and parenting styles), and social factors (e.g., need for financial support, other social, or environmental factors). Intervention is therefore a broad concept and is not just about medication. By having a “whole-system” approach, caregivers and TSC teams will think how to integrate healthcare, education, social wellbeing, and community participation into the intervention for the individual and family who live with TSC

9. Be evidence-based and evidence-informed. Even though there are many gaps in the TSC evidence base, specifically for the identification and treatment of TAND, all professionals should use evidence-based strategies as recommended in the general population and make recommendations in an evidence-informed manner, rather than use or recommend strategies or interventions that have no evidence-base or that may be harmful. In discussions with families, all professionals should be clear when advice is based on established evidence and when not

10. Strive for optimal functional outcomes and quality of life throughout the journey with TSC and TAND. The purpose of diagnosis and treatment should not simply be symptom control or removal of disorder/disease, but to achieve the optimal functional outcomes for individuals and families—this should include activities and participation (including education, occupation, and leisure), social inclusion (for the individual, caregivers, and family) and optimal quality of life (for the individual, caregivers, and family). Across the journey with TSC and TAND, different outcomes may become priorities, and different elements will ensure a good quality of life. These require review and re-focusing, particularly at key transitional timepoints, for instance moving from pre-school to school, moving out of formal education, and so on