Guanfacine as a Treatment Option for Persistent Mental Restlessness and Deliberate Self-harm Thoughts in a Patient with Attention-deficit/Hyperactivity Disorder, Autism Spectrum Disorder, Borderline Personality Disorder, and Post-traumatic Stress Disorder: Case Report.

Deliberate self-harm (DSH) in adolescents presents a significant clinical challenge, particularly when compounded by comorbidities such as attention-deficit/hyperactivity disorder (ADHD), autism spectrum disorder (ASD), borderline personality disorder (BPD), and post-traumatic stress disorder (PTSD). We describe a case of a 16-year-old transgender Māori male with ADHD, ASD traits, BPD, and PTSD, who presented with persistent mental restlessness experienced as intrusive DSH ideation. He had limited benefit and intolerable side effects with atomoxetine but responded to guanfacine modified-release. Guanfacine modified-release (1 mg nocte) treatment coincided with a marked reduction in mental restlessness and intrusive DSH ideation. During the follow-up period, there was a decrease in acute healthcare utilisation. Then the patient self-ceased guanfacine, coinciding with a return of DSH ideation and behaviours. We hypothesise that the ADHD-related mental restlessness was associated with intrusive DSH ideation; amelioration of mental restlessness and self-harm ideation by guanfacine can be interpreted as the 'dechallenge' phase of a 'challenge-dechallenge' natural experiment. This case provides novel evidence for the potential therapeutic role of guanfacine in mitigating persistent self-harm thoughts, via modulation of mental restlessness and impulsivity. Our observation provides preliminary evidence of the potential benefit of guanfacine in treating DSH, in the context of patients with co-occurring cognitive rigidity, trauma exposure, and emotional dysregulation. This case aligns with emerging evidence for the efficacy of guanfacine for ASD and trauma-related disorders, but is the first - in the existing literature - for ADHD and trauma history in an adolescent with BPD and transgender intersectionality.