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Trichotillomania/hair pulling disorder (HPD) and excoriation/skin picking disorder (SPD) are childhood-onset, body-focused repetitive behaviors that are thought to share genetic susceptibility and underlying pathophysiology with obsessive-compulsive disorder (OCD) and Tourette syndrome (TS). We sought to determine the prevalence of DSM-5 HPD and SPD in TS patients, and to identify clinical factors most associated with their co-morbidity with TS. Participants included 811 TS patients recruited from TS specialty clinics for a multi-center genetic study. Patients were assessed using standardized, validated semi-structured interviews. HPD and SPD diagnoses were determined using a validated self-report questionnaire. HPD/SPD prevalence rates were calculated, and clinical predictors were evaluated using regression modeling. 3.8 and 13.0% of TS patients met DSM-5 criteria for HPD and SPD, respectively. In univariable analyses, female sex, OCD, and both tic and obsessive-compulsive symptom severity were among those associated with HPD and/or SPD. In multivariable analyses, only lifetime worst-ever motor tic severity remained significantly associated with HPD. Female sex, co-occurring OCD, ADHD, and motor tic severity remained independently associated with SPD. This is the first study to examine HPD and SPD prevalence in a TS sample using semi-structured diagnostic instruments. The prevalence of HPD and SPD in TS patients, and their association with increased tic severity and co-occurring OCD, suggests that clinicians should screen children with TS and related disorders for HPD/SPD, particularly in females and in those with co-occurring OCD. This study also helps set a foundation for subsequent research regarding HPD/SPD risk factors, pathophysiology, and treatment models.

Introduction and objectives: Attention deficit hyperactivity disorder (ADHD) is a common and highly heritable neuropsychiatric disorder observed in children and adults. We have investigated the presence of genomic convergence in the top findings of the five published genome- wide association studies (GWAS) of ADHD. Methods: We conducted bioinformatics analyses and a systematic literature analysis of 85 ADHD candidate genes from the five GWAS that contained at least one single nucleotide polymorphism (SNP) yielding an association P value < 1.00E-04. Results and discussion: We found that 44 of the 85 top ADHD candidate genes fit into a network that links several neuronal cell membrane proteins with downstream-acting adaptor proteins and neuronal cytoskeleton/extracellular matrix associated proteins. Acting together, these proteins are involved in directed neurite outgrowth. Moreover, a number of proteins in the identified network are directly modulated by stimulants, the most commonly used psychopharmacological treatment for ADHD. Conclusion: We have identified a protein network that may provide an important contribution to our understanding of the molecular basis of ADHD and give clues to specific genes that should be tested in future studies. [ABSTRACT FROM AUTHOR]