(Cost)-Effectiveness of ABFT for Suicidal Youth.

Young adults who attempt to kill themselves is a common and serious mental health problem worldwide and certainly in Belgium and the Netherlands. Fatal suicide is the leading cause of death among young adults. It has devastating consequences both for the young adults themselves and for their families. It also has substantial economic costs. However, up until now, there is little research on the treatment of suicidality among young adults. The current psychological therapy approaches and drug treatments for young people at very high risk of fatal suicide attempts have only limited success. Increasing evidence indicates the importance of involving significant others in treatment and the importance of the unfulfilled need for belonging and secure attachment. The WHO recommends involving significant others in the treatment of suicidal young adults. However, in Belgium and the Netherlands, there is little knowledge on the effectiveness of family based treatments. Attachment Based Family Therapy, or ABFT, was shown to work well in several studies in the US. Also in Belgium and the Netherlands, ABFT is being used to treat suicidal young adults. However, how well it works compared to the current treatment and if it provides good value for money have not been studied in young adults. In the proposed study the investigators will test, in a real-life situation, whether ABFT works better than the current treatment and if it provides good value for money. This study is a collaboration between the Netherlands and Belgium and 6 or 7 sites will participate from each country. Sites can be hospitals, mental health centres, student health centres or private practices. Participants (138 individuals) are young adults between 18 and 25 years old who have frequent thoughts about killing themselves, and who seek mental health treatment. The investigators predict that, compared to current treatment, ABFT will reduce suicidal thoughts and suicide attempts and that this improvement will be maintained over time, and that it will be better value for money. The project will contribute to improving care for suicidal young adults with high suicide risk. Results will inform clinical guidelines and policymakers and improve the treatment of young adults with a high risk for fatal suicide, and their families.

The investigators conduct a randomized controlled trial to evaluate the (cost-)effectiveness of ABFT compared to Treatment As Usual (TAU) on suicidality, as delivered in daily practice. The hypothesis is that, compared to TAU, ABFT will lead to a stronger reduction of suicidal ideation and suicidal behavior, and will be more cost-effective, will improve family functioning and young adult attachment, and that this effect will hold at follow-up. The primary objective is change in suicidality, that is, suicidal ideation, attempts and suicide as assessed by the Suicidal Ideation Questionnaire Junior (SIQ-JR), and as reported by therapists during treatment. Secondary objectives are cost-effectiveness, process, working alliance and adherence during treatment, and change in young adult depressive symptoms, family functioning, and young adult attachment.

Attachment Based Family Therapy (ABFT): ABFT is a manualized treatment, that emerges from interpersonal theories that suggest suicide can be precipitated, exacerbated, or buffered against by the quality of family relationships. Therefore, ABFT focuses on strengthening parent-child attachment bonds to create a protective and secure base for young adult development. Sessions are scheduled weekly, and the intervention lasts on average 16 weeks. Treatment as usual (TAU): Participants in both arms will receive TAU, in the experimental condition ABFT will be delivered as an add-on. Most treatment centres' clinical practices rely heavily on the use of antidepressants and/or CBT or DBT. All regular interventions are allowed in TAU, except for systemic family therapy of more than 4 sessions in total. Parents are allowed to be involved in the treatment, which is part of treatment as usual, and can comprise for instance psycho-education or parental support or skill training.

Eligibility Criteria:
Inclusion Criteria:

* Aged between 18 and 25.
* A score above 31 on the SIQ-JR (the cut-off for suicidality).
* Have at least one primary parent or caregiver that participates in the assessment and treatment. This could be a biological parent, stepparent, grandparent, other relative, or a foster parent.

Exclusion Criteria:

* Other DSM-5 disorders: substance dependency: severe alcohol or cannabis use disorder, all other substances: modest or severe substance use disorder.
* Severe conduct disorder.
* Evidence of psychotic features or prior psychosis (assessed with the SCID-5-S).
* Severe cognitive impairment (e.g., mental retardation, severe developmental disorders) as evidenced by educational records, parental report and/or clinical impression.
* Other circumstances that might affect participation (e.g., severe medical disorder, relocation).