Rare de novo damaging DNA variants are enriched in attention-deficit/hyperactivity disorder and implicate risk genes.

Research demonstrates the important role of genetic factors in attention-deficit/hyperactivity disorder (ADHD). DNA sequencing of families provides a powerful approach for identifying de novo (spontaneous) variants, leading to the discovery of hundreds of clinically informative risk genes for other childhood neurodevelopmental disorders. This approach has yet to be extensively leveraged in ADHD. We conduct whole-exome DNA sequencing in 152 families, comprising a child with ADHD and both biological parents, and demonstrate a significant enrichment of rare and ultra-rare de novo gene-damaging mutations in ADHD cases compared to unaffected controls. Combining these results with a large independent case-control DNA sequencing cohort (3206 ADHD cases and 5002 controls), we identify lysine demethylase 5B (KDM5B) as a high-confidence risk gene for ADHD and estimate that 1057 genes contribute to ADHD risk. Using our list of genes harboring ultra-rare de novo damaging variants, we show that these genes overlap with previously reported risk genes for other neuropsychiatric conditions and are enriched in several canonical biological pathways, suggesting early neurodevelopmental underpinnings of ADHD. This work provides insight into the biology of ADHD and demonstrates the discovery potential of DNA sequencing in larger parent-child trio cohorts.

Clinical characteristics of probands with obsessive-compulsive disorder from simplex and multiplex families.

Genetic and non-genetic factors contribute to obsessive-compulsive disorder (OCD), with strong evidence of familial clustering. Genomic studies in psychiatry have used the concepts of families that are "simplex" (one affected) versus "multiplex" (multiple affected). Our study compares demographic and clinical data from OCD probands in simplex and multiplex families to uncover potential differences. We analyzed 994 OCD probands (501 multiplex, 493 simplex) from the Brazilian Research Consortium on Obsessive-Compulsive Spectrum Disorders (C-TOC). Clinicians administered the Structured Clinical Interview for DSM-IV (SCID-IV) to diagnose, Yale-Brown Obsessive-Compulsive Scale (Y-BOCS) to assess severity, and Dimensional Yale-Brown Obsessive-Compulsive Scale (DY-BOCS) to assess symptom dimensionality. Demographics, clinical history, and family data were collected. Compared to simplex probands, multiplex probands had earlier onset, higher sexual/religious and hoarding dimensions severity, increased comorbidity with other obsessive-compulsive-related disorders (OCRD), and higher family history of psychiatric disorders. These comparisons provide the first insights into demographic and clinical differences between Latin American simplex and multiplex families with OCD. Distinct clinical patterns may suggest diverse genetic and environmental influences. Further research is needed to clarify these differences, which have implications for symptom monitoring and management.

Animal hoarding: a systematic review

Objectives: Animal hoarding is a special manifestation of hoarding disorder, characterized by the accumulation of animals and failure to provide them with minimal care. The main objective of this systematic review is to evaluate the characteristics of animal hoarding, focusing on the profile of affected individuals and the features of accumulation behavior. Methods: A systematic search of the literature was conducted in the electronic databases MEDLINE, Scopus, and LILACS until October 2022. We included case series (n ≥ 10) and cross-sectional studies assessing animal hoarding. Results: A total of 374 studies were initially retrieved. Most studies were classified as having poor quality and significant risk of bias. A total of 538 individuals with animal hoarding were evaluated. These individuals were predominantly middle-aged, unmarried women who lived alone in urban areas. Most of their residences had unsanitary conditions. Recidivism rates varied from 13-41%. Cats and dogs were the main hoarded species, mostly acquired through unplanned breeding, and disease, injury, behavioral problems, and a lack of hygiene were characreristic of their condition. Animal carcasses were found in up to 60% of the properties. Conclusion: Animal hoarding is a complex condition that requires urgent attention. More research is necessary to develop effective strategies that can save community resources, improve animal and human welfare, and prevent recidivism.

Animal Hoarding: a systematic review.

OBJECTIVE: Animal hoarding is a special manifestation of Hoarding Disorder, characterized by the accumulation of animals and failure to provide them with minimal care. The main objective of this systematic review is to evaluate the characteristics of animal hoarding with a focus on the profile of affected individuals and accumulation behavior features. METHODS: A systematic search of the literature using the electronic databases MEDLINE, SCOPUS and LILACS was conducted until October 2022. We included case series (n ≥ 10) and cross-sectional studies assessing animal hoarding. RESULTS: 374 studies were initially retrieved. Most studies were classified as poor quality and significant risk of bias. 538 individuals with animal hoarding were evaluated. These individuals were predominantly middle-aged, unmarried females who lived alone in urban areas. Most residences presented unsanitary conditions. Recidivism rates varied from 13-41%. Cats and dogs were the main hoarded species, mostly acquired through unplanned breeding and found with lack of hygiene; diseases; injuries; and behavioral problems. Animal carcasses were found in up to 60% of the properties. CONCLUSION: Animal hoarding is a complex condition that requires urgent attention. More research is necessary to develop effective strategies that can save community resources, improve animal and human welfare, and prevent recidivism.