Hoarding: A meta‐analysis of age of onset

Hoarding disorder is present in 2–6% of the population and can have an immense impact on the lives of patients and their families. Before its inclusion the Diagnostic and Statistical Manual of Mental Disorders, 5th edition, pathological hoarding was often characterized as a symptom of obsessive–compulsive disorder, and several different diagnostic assessment methods were used to identify and characterize it. Although the age of onset of pathological hoarding is an important epidemiological measure, as clarifying the age of onset of hoarding symptoms may allow for early identification and implementation of evidence‐based treatments before symptoms become clinically significant, the typical age of onset of hoarding is still uncertain. To that end, this study is a systematic review and meta‐analysis of research published in English between the years 1900 and 2016 containing information on age of onset of hoarding symptoms. Twenty‐five studies met inclusion criteria. The mean age of onset of hoarding symptoms across studies was 16.7 years old, with evidence of a bimodal distribution of onset. The authors conclude by discussing practice implications for early identification and treatment.     

Endogenous nociceptin/orphanin‐fq in the dorsal hippocampus facilitates despair‐related behavior

Nociceptin/orphanin‐FQ (N/OFQ) peptide and its receptor (NOP: N/OFQ opioid peptide receptor) are highly expressed in the hippocampus, but their functional role remains poorly understood. We recently showed that hippocampal N/OFQ inhibits learning and memory abilities in mice. Here, we investigated whether the endogenous peptide also regulated emotional responses at the level of the hippocampus. Bilateral infusions of the selective NOP receptor antagonist, UFP‐101 (1–3 nmol/side), into the dorsal hippocampus produced antidepressant‐like effects in the mouse forced swim and tail suspension tests comparable with those obtained with the prototypical antidepressant, fluoxetine (10–30 mg/kg, intraperitoneal). In the light‐dark test, neither UFP‐101 (1–3 nmol/side) nor N/OFQ peptide (1–3 nmol/side) modified anxiety measures when injected at behaviorally active doses in the dorsal hippocampus. These findings show a clear dissociation in the involvement of hippocampal N/OFQ system in anxiety‐ and despair‐related behaviors. We conclude that the dorsal hippocampus is a brain region in which there is an important N/OFQ modulation of mnemonic processes and adaptive emotional responses associated to despair states. © 2010 Wiley‐Liss, Inc.