title: Effects of CLOCK gene variants and early stress on hopelessness and suicide in bipolar depression.
abstract: BACKGROUND
  Patients with mood disorders show a high dependence of behavior on the molecular characteristics of the biological clock. CLOCK rs1801260 gene polymorphism influences circadian behavior in bipolar disorder (BD), with *C carriers showing a delayed sleep onset and worse insomnia. Sleep phase delay and insomnia associate with suicide in the general population.
  
  
  METHODS
  We investigated the effects of rs1801260, and of exposure to stressful life events, on current suicidal ideation and history of suicide attempts in 87 depressed patients with BD.
  
  
  RESULTS
  rs1801260*C carriers currently showed worse Hamilton Depression Rating Scale scores for suicide and worse ratings for depressive cognitive distortions. Previous history of attempted suicide associated with exposure to higher stressful events in the early life, with rs1801260*C carriers showing a higher dependency of the modeled probability of attempting suicide on the severity of exposure to early stress.
  
  
  CONCLUSIONS
  CLOCK rs1801260 modulated the relationship between early stress, adult history of attempted suicide and current suicide ideation. Factors affecting the biological clock can influence "non-clock" core psychopathological features of mood disorders.
authors.affiliation: a Department of Clinical Neurosciences , Scientific Institute Ospedale San Raffaele and University Vita-Salute , Milano, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Benedetti
authors.affiliation: a Department of Clinical Neurosciences , Scientific Institute Ospedale San Raffaele and University Vita-Salute , Milano, Italy.
authors.forename: Roberta
authors.initials: R
authors.lastname: Riccaboni
authors.affiliation: a Department of Clinical Neurosciences , Scientific Institute Ospedale San Raffaele and University Vita-Salute , Milano, Italy.
authors.forename: Sara
authors.initials: S
authors.lastname: Dallaspezia
authors.affiliation: a Department of Clinical Neurosciences , Scientific Institute Ospedale San Raffaele and University Vita-Salute , Milano, Italy.
authors.forename: Clara
authors.initials: C
authors.lastname: Locatelli
authors.affiliation: a Department of Clinical Neurosciences , Scientific Institute Ospedale San Raffaele and University Vita-Salute , Milano, Italy.
authors.forename: Enrico
authors.initials: E
authors.lastname: Smeraldi
authors.affiliation: a Department of Clinical Neurosciences , Scientific Institute Ospedale San Raffaele and University Vita-Salute , Milano, Italy.
authors.forename: Cristina
authors.initials: C
authors.lastname: Colombo
mesh_terms: D000328:Adult; D001714:Bipolar Disorder / Q000235:genetics* / Q000523:psychology; D056926:CLOCK Proteins / Q000235:genetics*; D002940:Circadian Rhythm / Q000235:genetics* / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D019964:Mood Disorders / Q000235:genetics / Q000523:psychology; D011569:Psychiatric Status Rating Scales; D012307:Risk Factors; D007319:Sleep Initiation and Maintenance Disorders / Q000235:genetics; D012893:Sleep Wake Disorders / Q000235:genetics / Q000523:psychology; D013312:Stress, Physiological / Q000502:physiology*; D013405:Suicide / Q000523:psychology; D055815:Young Adult
chemical_list: D056926:CLOCK Proteins; C538943:CLOCK protein, human
keywords: Bipolar disorder; childhood trauma; clock; depression; stress; suicide