7. Details of the comparator interventions examined in the 19 included studies.

Study	Comparator
Woody 1985	SM: an individual counselling intervention focused on providing external services rather than dealing with intrapsychic processes, plus methadone maintenance
McKay 2000	TAU: standard continuing care comprising 2 group therapy sessions per week where the orientation was a mix of addictions counselling and 12‐step recovery practices
Messina 2003	SM: methadone maintenance; treatment, with daily clinic visits for methadone, twice‐monthly counselling sessions, plus medical care and case management visits, as required
Tyrer 2004	TAU: participants were seen by another designated therapist and offered the standard treatment in the area concerned or the continuation of current therapy.
Ball 2005	TAU: standard group substance abuse counselling as normally provided at the drop‐in centre where clients are typically offered a total of 3 opportunities per week to attend group psychoeducation and counselling sessions
Havens 2007	Passive referral: strengths‐based case management (SBCM) of 0 to 4 minutes duration
Huband 2007	TAU: placed on waiting list for active intervention
Marlowe 2007	Standard (‘unmatched’) schedule court hearings requiring attendance every 4 to 6 weeks
Neufeld 2008	SM: standard methadone substitution treatment and participants attended 2 individual counselling sessions per week
Woodall 2007	Incarceration
Davidson 2009	TAU: “all participants received whatever treatment they would have received had the trial not taken place” (quote; p 570, column 2)
Tarrier 2010	TAU: “Group‐based enhanced thinking skills and sex offender treatment were the most frequently provided therapies recorded on the TAU logs." (quote; p 14); other noted TAU therapies included: social therapy and resettlement work; review of clinical or psychology reports; discussion of therapy; neurorehabilitation; review of previous assessments; end of therapy meeting support work; and "talking sessions” (quote; p 14)
Bernstein 2012	TAU: standard treatment that patients receive at each clinic usually another (non‐ST) form of individual psychotherapy such as cognitive‐behaviour therapy, psychodynamic therapy, or client‐centred therapy
Feigenbaum 2012	TAU: range of individualised service provision, including outpatient psychiatric review, case management, psychoanalytic psychotherapy, cognitive behaviour therapy, supportive structured counselling, inpatient admission, drug and alcohol treatment and crisis management
Priebe 2012	TAU: participants allocated to the TAU condition were referred back to the referrer and encouraged to engage in any kind of treatment other than DBT; "this may have included treatment from psychotherapists, psychiatrists, community mental health teams, counsellors, general practitioners or user‐run support groups, all of which were offered free of charge under the NHS." (quote; p 358)
Asmand 2015	TAU: unclear but TAU control group may have received individual work, but no details were provided
Thylstrup 2015	TAU: access to opioid substitution treatment (if required); psychosocial support such as casework, counselling, or referral to residential rehabilitation; referral to 'off‐site' psychiatrist for treatment of other psychiatric conditions
McMurran 2016	TAU: provided by participants’ usual‐care teams; TAU includes assessment, care planning, risk assessment and psychological interventions; participants excluded at baseline if accessing/likely to access psychological treatment programme specifically designed for personality disorder.
Nathan 2019	TAU: standard probation supervision following release from prison; TAU comprises regular meetings (weekly initially) with the offender manager and engagement with other services where specified in the licence conditions.

SBCM = Strengths‐based case management
SM = Standard maintenance
TAU = Treatment as usual