Forty-six studies were included in the review: 22 focused on behavioural parent training programs; 22 on behavioural classroom management; and 22 on behavioural peer interventions. Twelve were Type 1, 27 Type 2 and seven Type 3.
Behavioural interventions versus no-treatment control (25 studies): The median SMD was 0.44 (range -0.03 to 1.31; nine studies) for between-group designs, 0.46 (range 0.10 to 2.39; six studies) for within-subject designs and 3.46 (range 1.07 to 14.35; 10 studies) for single-subject studies, which indicated benefits of behavioural interventions.
Behavioural interventions versus alternative treatment (14 studies): Compared with medication, median SMD was 0.11 (range -0.24 to 0.20; six studies) for between-group designs, -0.27 (range -3.39 to 0.47; four studies) for within-subject designs and 0.56 (range -0.94 to 2.56; four studies) for single-subject studies, which indicated benefits of behavioural interventions with the exception of within-subject designs.
Pre-treatment versus post-treatment (19 studies): The median SMD was 0.61 (range -0.16 to 1.63; 15 studies) for between-group designs and 1.78 (range 1.29 to 10.09; four studies) for single-subject studies, which indicated benefits of behavioural interventions compared with pretreatment functioning.