Table 5.

Definitions of Interventions

Categories of Interventions	Intervention Type	Definition
1. Individual and family therapies	1a. Cognitive Behavioural Therapy (CBT)	A type of short-term psychotherapy, based on a pro-active and shared therapeutic relationship between a therapist and client, that enables an individual to develop skills and strategies to make sense of the present [19]. CBT is structured and time-limited (i.e. typically 6–20 sessions), and allows the client to identify, challenge and change thoughts, attitudes and beliefs that may trigger emotional and behavioural difficulties [46, 47, 49, 50]. Usually, CBT is effective in treating anxiety and depression, but also conditions such as bipolar disorder, schizophrenia and psychosis [19]. Includes: - Community reinforcement approach (CRA): a CBT-based therapy that recognizes the impact that the environment/community (i.e. family, hobbies, work, friends, etc.) can have on an individual. CRA permits the individual to modify environmental factors such as developing communication, problem solving and job skills, in order to support the recovery process [54]. - Dialectical behaviour therapy: the client is taught that their experiences and behaviours are valid (i.e. acceptance), and that, in order to move on and manage their emotions, they must make positive changes (i.e. change) [55].
	1b. Family Therapy	A type of psychotherapy that aims for family preservation by promoting support and understanding among family members during times of instability, uncertainty, anger, grief, or trauma [20, 29]. By providing a safe environment, Family Therapy focuses on intrapersonal factors that support family cohesion and re-establishing connections; it seeks to understand individual behaviour and interactions between the individual and their family in order to reduce defensive communication patterns. The duration of sessions is client-dependent, varying from a few sessions (2–3) to longer. Ecologically Based Family Therapy is a home-based model, while Functional Family Therapy is provided in a professional setting [46, 47, 49].
	1c. Motivational Interviewing	A collaborative, person-centered counselling approach based on empathy and self-efficacy that is often used to address risky sexual health behaviours, alcohol and drug use, and mental health issues [21, 48]. Motivational interviewing can be a single session or multiple sessions with a clinical psychologist or other trained health workers, with the objective of building self-confidence and developing independence to strengthen the motivation for change [56].
2. Skill building programs	Life skills training program Mindfulness Strengths-based	Life Skills Training enables youth 16 years and older to adopt and develop key competency skill areas in education, employment, daily living skills, survival skills, choices and consequences, and interpersonal/social domains. Life Skills Training also includes an extensive outreach component in order to recruit youth into the program and provide short-term case management support [40, 41]. Mindfulness (SAFE intervention): Through a three-day workshop, youth are invited to adapt concepts of mindfulness, with a focus on internal, interpersonal, and environmental cues, and fostering assertiveness and problem- solving skills, and strategies for asking for help [42]. Strengths-based intervention (Houvast) enables and promotes self-agency in his or her own recovery process, by goal-setting, identifying ineffective strategies and problems in the way of achieving set goals [39].
3. Case management		Case management is health and social service where an individual is assigned a case manager who plans and facilitates access to health and social care services required for recovery [22]. Intensive case management is provided to individuals with serious mental health disorders and struggling with addictions [57]. The case manager accompanies the service user to meetings and can be available for up to12 hours per day, 7 days a week. One form of time-limited intensive case management is critical time intervention, which supports continuity of care and facilitates access to services for clients during transitions (e.g. from a shelter to independent housing or following discharge from a hospital) [43]. Critical time intervention is often offered for a period of 6–9 months.
4. Structural Support	4a. Housing Programs	Housing First is a housing model that provides immediate access to permanent independent housing in the community and is not contingent on sobriety or abstinence or treatment. Individuals enrolled in the Housing First program are typically given access to scattered-site housing of their choice with mobile and off-site mental health services. Supported Housing: safe and affordable housing with integrated health and social support services [35]. The supportive service (usually Assertive community treatment) is provided by a multidisciplinary team. Independent Living Programs aim is to provide homeless and vulnerably housed youth with life skills through a structured and supervised residential [33].
	4b. Drop-in Centre 4b. Shelter Services	Drop-in Centers: offered for youth 24 h/7 days a week, and provides access to food, laundry, and shower facilities, as well as recreational activities (e.g. television, books, board games or video games), and opportunities for socialization [44]. Drop-in staff often link youth with community resources (i.e. counseling and housing programs). Shelter Services: provide a temporary overnight alternative to street living, and is open 24 h/day, 7 days a week [44].