Atypical antipsychotic medications, which are approved for the treatment of certain behavioral disorders, are sometimes prescribed off-label as a combination therapy with stimulants for the treatment of comorbid (i.e., co-occurring diseases) ADHD and disruptive behavioral disorders. Canadian clinical practice guidelines only support the use of dopaminergic antipsychotics with selectivity for D2-type dopamine receptors, particularly risperidone, as a third-line treatment for both disorders following the failure of stimulant monotherapy and psychosocial interventions. Combined use of D2-type receptor antagonists and ADHD stimulants for the treatment of ADHD with comorbid behavioral disorders does not appear to have significantly worse adverse effects than ADHD stimulant or antipsychotic monotherapy. Research suggests, but has not yet confirmed, the treatment efficacy of antipsychotic and stimulant combination treatment for both disorders; it is unclear if the combination therapy for both disorders is superior to stimulant or antipsychotic monotherapy. There is no evidence to support the use of any subclass of antipsychotics for the treatment of the core symptoms of ADHD (i.e., inattention and hyperactivity) without comorbid behavioral disorders.