title: Low neuropeptide Y in cerebrospinal fluid in bipolar patients is associated with previous and prospective suicide attempts.
abstract: The attempted and accomplished suicide rates in patients with bipolar disorder are 40-50% and 15-20%, respectively. No biological markers that help predict suicide been identified. Human and experimental animal data indicate that dysregulation of the neuropeptide Y (NPY) system plays a role in depression, anxiety, and posttraumatic stress disorder (PTSD). The aim of this study was to explore if low cerebrospinal fluid (CSF) NPY is associated with (1) past suicide attempts, (2) future suicide attempts, and (3) trait anxiety. Lumbar puncture was performed on 120 clinically stable patients with bipolar disorder enrolled in the St Göran Bipolar Project, where the number of previous suicide attempts was documented. NPY-like immunoreactivity (NPY-LI) was determined in cerebrospinal fluid (CSF). Patients were reexamined one year after the lumbar puncture and suicide attempts were recorded. NPY-LI was significantly lower in patients with a history of suicide attempt than in patients who had not attempted suicide prior to lumbar puncture. Importantly, NPY-LI was markedly lower in patients who made a suicide attempt during the follow-up period compared to patients who did not. Patients who attempted suicide during the follow-up also had markedly lower NPY-LI than those with previous suicide attempts who did not reattempt. Our results suggest that low CSF NPY-LI predicts future suicide attempts. The data are in line with the hypothesis that NPY signaling is altered in affective disorders and states of emotional dysregulation.
authors.affiliation: Institute of Neuroscience and Physiology, The Sahlgrenska Academy at Gothenburg University, Gothenburg, Sweden. Electronic address: johan.sandberg@neuro.gu.se.
authors.forename: Johan V
authors.initials: JV
authors.lastname: Sandberg
authors.affiliation: Institute of Neuroscience and Physiology, The Sahlgrenska Academy at Gothenburg University, Gothenburg, Sweden.
authors.forename: Joel
authors.initials: J
authors.lastname: Jakobsson
authors.affiliation: Institute of Neuroscience and Physiology, The Sahlgrenska Academy at Gothenburg University, Gothenburg, Sweden.
authors.forename: Erik
authors.initials: E
authors.lastname: Pålsson
authors.affiliation: Institute of Neuroscience and Physiology, The Sahlgrenska Academy at Gothenburg University, Gothenburg, Sweden; Section of Psychiatry, Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Mikael
authors.initials: M
authors.lastname: Landén
authors.affiliation: Section of Psychiatry, Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Aleksander A
authors.initials: AA
authors.lastname: Mathé
mesh_terms: D000328:Adult; D000367:Age Factors; D001007:Anxiety / Q000134:cerebrospinal fluid / Q000150:complications; D015415:Biomarkers / Q000134:cerebrospinal fluid; D001714:Bipolar Disorder / Q000134:cerebrospinal fluid* / Q000150:complications; D005260:Female; D006801:Humans; D008297:Male; D009478:Neuropeptide Y / Q000134:cerebrospinal fluid*; D010551:Personality; D011446:Prospective Studies; D011619:Psychotropic Drugs / Q000494:pharmacology; D012737:Sex Factors; D013406:Suicide, Attempted; D055815:Young Adult
chemical_list: D015415:Biomarkers; D009478:Neuropeptide Y; D011619:Psychotropic Drugs
keywords: Biomarker; Bipolar disorder; Cerebrospinal fluid; Neuropeptide Y; Suicide attempt; Suicide prevention