Medications used to treat autism spectrum disorder behaviours and symptoms
| Medication | Target behaviour | Evidence | On- or off-label | Adverse events* |
|---|---|---|---|---|
| Atypical antipsychotic medications (i.e., aripiprazole risperidone) | Irritability, aggression† | Multiple, well-designed RTCs supporting their use69,75 | FDA indication | Weight gain, metabolic syndrome, gastrointestinal effects, sedation, akathisia, orthostatic hypotension, tachycardia, extra- pyramidal syndrome, neuroleptic malignant syndrome (rare) |
| Repetitive behaviours‡ | ≥ 2 large RCTs support efficacy (although not a primary outcome measure)69,75 | Off-label | ||
| Serotonin reuptake inhibitors | Repetitive behaviour§ | 1 unpublished and 1 published large RCT (fluoxetine, citalopram): no evidence for efficacy70 | Off-label, unless comorbid obsessive–compulsive disorder | Gastrointestinal effects, insomnia, agitation, disinhibition, dry mouth, headache, sexual dysfunction |
| Anxiety or depression | None in autism, but multiple studies for pediatric anxiety disorders and depression | On-label for anxiety disorders and depression | ||
| Stimulants | ADHD-like symptoms¶ | > 2 RCTs (methylphenidate) support its use76; smaller studies support longer-acting stimulants | On-label for ADHD | Poor appetite, weight loss, irritability, insomnia |
| Atomoxetine | ADHD-like symptoms** | 1 large, 1 small RCT support effectiveness77,78 | On-label for ADHD | Gastrointestinal effects, insomnia, orthostatic hypotension |
| α-agonists | ADHD-like symptoms | Several small RCT and open label studies in autism support efficacy79 | Clonidine: off-label; guanfacine: FDA indication for ADHD†† | Somnolence, hypotension, bradycardia, dry mouth, constipation, irritability |
| Melatonin | Initial insomnia‡‡ | Cochrane meta-analysis, positive effect on initial insomnia compared to placebo80 | Not regulated | Headache, dizziness and nausea (all rare outcomes) |
Note: ADHD = attention–deficit/hyperactivity disorder, CI = confidence interval, FDA = US Food and Drug Administration, RCT = randomized controlled trial.
↵* Commonly reported adverse events. This list is not exhaustive.
↵† Risperidone: effect size 1.2, p < 0.001; aripiprazole: difference in least square means: −7.9 (95% CI −11.7 to −4.1), p < 0.001.
↵‡ Risperidone (Aberrant Behavior Checkliststereotypye) effect size: 0.8, p < 0.001; aripiprazole: Child Yale Brown Obsessive Compulsive Scale: difference in least square means: −3 (95% CI −4.3 to −1.6), p < 0.001.
↵§ Citalopram: relative risk 0.969 (95% CI 0.61 to 1.51), p > 0.99.
↵¶ Optimal dose methylphenidate: SNAP-IVADHD: d = 0.73, p < 0.001.
↵** Atomoxetine: ADHD rating scale total score: difference in least square means: −6.7 (95%CI −10 to −3.4), p < 0.001.
↵†† Available in Canada through exceptional access programs.
↵‡‡ Melatonin: sleep duration: Hedge’s g: 1.97 (95%CI 1.10 to 2.84); sleep onset latency: Hedge’s g: −2.42 (95%CI −1.96 to 2.98).