*Article* **Behavioral Deficits in Juvenile Onset Huntington's Disease**

#### **Kathleen E. Langbehn 1,\*, Ashley M. Cochran 1, Ellen van der Plas 1, Amy L. Conrad 2, Eric Epping 1, Erin Martin 1, Patricia Espe-Pfeifer 1 and Peg Nopoulos 1,2,3,\***


Received: 14 July 2020; Accepted: 7 August 2020; Published: 11 August 2020

**Abstract:** Reports of behavioral disturbance in Juvenile-Onset Huntington's Disease (JOHD) have been based primarily on qualitative caregiver reports or retrospective medical record reviews. This study aims to quantify differences in behavior in patients with JOHD using informant- and self-report questionnaires. Informants of 21 children/young adults (12 female) with JOHD and 115 children/young adults (64 female) with a family history of Huntington's Disease, but who did not inherit the disease themselves (Gene-Non-Expanded; GNE) completed the Behavior Rating Inventory of Executive Function (BRIEF) and the Pediatric Behavior Scale (PBS). Mixed linear regression models (age/sex adjusted) were conducted to assess group differences on these measures. The JOHD group had significantly higher scores, indicating more problems, than the GNE group on all BRIEF subscales, and measures of Aggression/Opposition and Hyperactivity/Inattention of the PBS (all *p* < 0.05). There were no group differences in Depression/Anxiety. Inhibit, Plan/Organize, Initiate, and Aggression/Opposition had significant negative correlations with Cytosine-Adenine-Guanine (CAG) repeat length (all *p* < 0.05) meaning that individuals with higher CAG repeats scored lower on these measures. There was greater discrepancy between higher informant-vs. lower self-reported scores in the JOHD group, supporting the notion of lack of insight for the JOHD-affected group. These results provide quantitative evidence of behavioral characteristics of JOHD.

**Keywords:** Huntington's disease; behavioral regulation; executive function; trinucleotide repeat disorder
