Atomoxetine for hoarding disorder: A pre-clinical and clinical investigation.
Despite several studies suggested that inattention and impulsivity-compulsivity could represent two core dimensions of hoarding disorder (HD), only a small case series study investigated the effectiveness of attention-deficit-hyperactivity-disorder (ADHD) medications in HD. The aim of the present study was to target attentional and inhibitory control networks in HD patients through the ADHD medication atomoxetine, moving from a preclinical investigation on an animal model of compulsive-like behavior (marble burying test) to a clinical investigation on both medicated and unmedicated patients with a primary diagnosis of HD without ADHD. Our preclinical investigation showed that acute administration of atomoxetine significantly reduced the compulsive-like behaviours of mice in the marble burying test without affecting neither locomotor activity and coordination nor exploration behaviours. When compared, atomoxetine and fluoxetine showed similar effects on the marble burying test. However, fluoxetine impaired both locomotor and exploratory activity. In our clinical investigation 12 patients were enrolled and 11 patients completed an open trial with atomoxetine at flexible dose (40-80 mg) for 12 weeks. At the endpoint the mean UCLA Hoarding Severity Scale score decreased by 41.3% for the whole group (p = 0003). Six patients were classified as full responders (mean symptom reduction of 57.2%) and three patients as partial responders (mean symptom reduction of 27.3%). Inattentive and impulsivity symptoms showed a significant mean score reduction of 18.5% from baseline to the endpoint (F (1,9) = 20.9, p = 0.0013). Hoarding symptoms improvement was correlated to reduction of patients' disability and increased in their global functioning. These preclinical and clinical data suggest that atomoxetine may be effective for HD and therefore should be considered for future controlled trials.
University of Florence, Department of Neuroscience, Psychology, Drug Research and Child Health, Neurofarba, via delle Gore 2H, 50141, Florence, Italy; Institute of Neuroscience, via La Marmora 24, 50121, Florence, Italy. Electronic address: giacomograssimd@gmail.com.
Giacomo
G
Grassi
Department of Neuroscience, Psychology, Drug Research and Child Health, Neurofarba, Pharmacology and Toxicology Section, University of Florence, Florence, Italy.
Laura
L
Micheli
Department of Neuroscience, Psychology, Drug Research and Child Health, Neurofarba, Pharmacology and Toxicology Section, University of Florence, Florence, Italy.
Lorenzo
L
Di Cesare Mannelli
University of Florence, Department of Neuroscience, Psychology, Drug Research and Child Health, Neurofarba, via delle Gore 2H, 50141, Florence, Italy.
Elisa
E
Compagno
University of Siena, Department of Molecular and Developmental Medicine, Siena, Italy.
Lorenzo
L
Righi
Department of Neuroscience, Psychology, Drug Research and Child Health, Neurofarba, Pharmacology and Toxicology Section, University of Florence, Florence, Italy.
Carla
C
Ghelardini
University of Florence, Department of Neuroscience, Psychology, Drug Research and Child Health, Neurofarba, via delle Gore 2H, 50141, Florence, Italy; Institute of Neuroscience, via La Marmora 24, 50121, Florence, Italy.
Stefano
S
Pallanti
D018759:Adrenergic Uptake Inhibitors / Q000627:therapeutic use*; D000328:Adult; D000818:Animals; D018687:Antidepressive Agents, Second-Generation / Q000627:therapeutic use; D000069445:Atomoxetine Hydrochloride / Q000627:therapeutic use*; D001289:Attention Deficit Disorder with Hyperactivity / Q000188:drug therapy / Q000503:physiopathology*; D001522:Behavior, Animal / Q000187:drug effects; D004195:Disease Models, Animal; D005260:Female; D005473:Fluoxetine / Q000627:therapeutic use; D005500:Follow-Up Studies; D000067836:Hoarding Disorder / Q000188:drug therapy*; D006801:Humans; D007175:Impulsive Behavior / Q000187:drug effects*; D008124:Locomotion / Q000187:drug effects; D008297:Male; D051379:Mice; D008875:Middle Aged; D009043:Motor Activity / Q000187:drug effects; D011569:Psychiatric Status Rating Scales; D045442:Rotarod Performance Test; D018709:Statistics, Nonparametric
D018759:Adrenergic Uptake Inhibitors; D018687:Antidepressive Agents, Second-Generation; D005473:Fluoxetine; D000069445:Atomoxetine Hydrochloride
Atomoxetine; Attention; Compulsivity; Hoarding disorder; Impulsivity; Marble burying test