Aas , M , Dazzan , P , Fisher , HL , Morgan , C , Morgan , K , Reichenberg , A , Zanelli , J , Fearon , P , Jones , PB , Murray , RM , Pariante , CM ( 2011 ). Childhood trauma and cognitive function in first-episode affective and non-affective psychosis . Schizophrenia Research 129 , 12 – 19 .

Akiskal , KK , Akiskal , HS ( 2005 ). The theoretical underpinnings of affective temperaments: implications for evolutionary foundations of bipolar disorder and human nature . Journal of Affective Disorders 85 , 231 – 239 .

Andreasen , NC , Flaum , M , Arndt , S ( 1992 ). The Comprehensive Assessment of Symptoms and History (CASH). An instrument for assessing diagnosis and psychopathology . Archives of General Psychiatry 49 , 615 – 623 .

Apeldoorn , SY , Sterk , B , van den Heuvel , ER , Schoevers , RA , Islam , MA , Bruggeman , R , Cahn , W , de Haan , L , Kahn , RS , Meijer , CJ , Myin-Germeys , I , van Os , J , Wiersma , D ( 2014 ). Factors contributing to the duration of untreated psychosis . Schizophrenia Research 158 , 76 – 81 .

Arts , B , Jabben , N , Krabbendam , L , van Os , J ( 2008 ). Meta-analyses of cognitive functioning in euthymic bipolar patients and their first-degree relatives . Psychological Medicine 38 , 771 – 785 .

Balanza-Martinez , V , Rubio , C , Selva-Vera , G , Martinez-Aran , A , Sanchez-Moreno , J , Salazar-Fraile , J , Vieta , E , Tabares-Seisdedos , R ( 2008 ). Neurocognitive endophenotypes (endophenocognitypes) from studies of relatives of bipolar disorder subjects: a systematic review . Neuroscience Biobehavioral Reviews 32 , 1426 – 1438 .

Barro , RJ , Lee , JW ( 2013 ). A new data set of educational attainment in the world, 1950–2010 . Journal of Development Economics 104 , 184 – 198 .

Blyler , CR , Gold , JM , Iannone , VN , Buchanan , RW ( 2000 ). Short form of the WAIS-III for use with patients with schizophrenia . Schizophrenia Research 46 , 209 – 215 .

Bora , E , Pantelis , C ( 2015 ). Meta-analysis of cognitive impairment in first-episode bipolar disorder: comparison with first-episode schizophrenia and healthy controls . Schizophrenia Bulletin 41 , 1095 – 1104 .

Bora , E , Yucel , M , Pantelis , C ( 2009 ). Cognitive endophenotypes of bipolar disorder: a meta-analysis of neuropsychological deficits in euthymic patients and their first-degree relatives . Journal of Affective Disorders 113 , 1 – 20 .

Cannon , TD , Huttunen , MO , Lonnqvist , J , Tuulio-Henriksson , A , Pirkola , T , Glahn , D , Finkelstein , J , Hietanen , M , Kaprio , J , Koskenvuo , M ( 2000 ). The inheritance of neuropsychological dysfunction in twins discordant for schizophrenia . The American Journal of Human Genetics 67 , 369 – 382 .

Chamorro-Premuzic , T , Furnham , A ( 2003 ). Personality predicts academic performance: evidence from two longitudinal university samples . Journal of Research in Personality 37 , 319 – 338 .

Coffman , JA , Bornstein , RA , Olson , SC , Schwarzkopf , SB , Nasrallah , HA ( 1990 ). Cognitive impairment and cerebral structure by MRI in bipolar disorder . Biological Psychiatry 27 , 1188 – 1196 .

Davies , G , Tenesa , A , Payton , A , Yang , J , Harris , SE , Liewald , D , Ke , X , Le Hellard , S , Christoforou , A , Luciano , M , McGhee , K , Lopez , L , Gow , AJ , Corley , J , Redmond , P , Fox , HC , Haggarty , P , Whalley , LJ , McNeill , G , Goddard , ME , Espeseth , T , Lundervold , AJ , Reinvang , I , Pickles , A , Steen , VM , Ollier , W , Porteous , DJ , Horan , M , Starr , JM , Pendleton , N , Visscher , PM , Deary , IJ ( 2011 ). Genome-wide association studies establish that human intelligence is highly heritable and polygenic . Molecular Psychiatry 16 , 996 – 1005 .

Deary , IJ , Penke , L , Johnson , W ( 2010 ). The neuroscience of human intelligence differences . Nature Reviews Neuroscience 11 , 201 – 211 .

Deary , IJ , Strand , S , Smith , P , Fernandes , C ( 2007 ). Intelligence and educational achievement . Intelligence 35 , 13 – 21 .

Dickson , H , Laurens , KR , Cullen , AE , Hodgins , S ( 2012 ). Meta-analyses of cognitive and motor function in youth aged 16 years and younger who subsequently develop schizophrenia . Psychological Medicine 42 , 743 – 755 .

Egeland , JA , Hostetter , AM , Pauls , DL , Sussex , JN ( 2000 ). Prodromal symptoms before onset of manic-depressive disorder suggested by first hospital admission histories . Journal of the American Academy of Child and Adolescent Psychiatry 39 , 1245 – 1252 .

Elvevag , B , Goldberg , TE ( 2000 ). Cognitive impairment in schizophrenia is the core of the disorder . Critical Reviews in Neurobiology 14 , 1 – 21 .

Eric , YW , Halari , R , Cheng , KM , Leung , SK , Young , AH ( 2013 ). Cognitive performance is impaired in euthymic Chinese patients with Bipolar 1 Disorder . Journal of Affective Disorders 151 , 156 – 163 .

First , MB , Spitzer , RL , Gibbon , M , Williams , JBW ( 1997 ). Structured Clinical Interview for DSM-IV Axis I Disorders (SCID I) . Biometric Research Department : New York .

Frangou , S , Haldane , M , Roddy , D , Kumari , V ( 2005 ). Evidence for deficit in tasks of ventral, but not dorsal, prefrontal executive function as an endophenotypic marker for bipolar disorder . Biological Psychiatry 58 , 838 – 839 .

Frantom , LV , Allen , DN , Cross , CL ( 2008 ). Neurocognitive endophenotypes for bipolar disorder . Bipolar Disorders 10 , 387 – 399 .

Gale , CR , Batty , GD , McIntosh , AM , Porteous , DJ , Deary , IJ , Rasmussen , F ( 2013 ). Is bipolar disorder more common in highly intelligent people? A cohort study of a million men . Molecular Psychiatry 18 , 190 – 194 .

Hughes , C , Kumari , V , Das , M , Zachariah , E , Ettinger , U , Sumich , A , Sharma , T ( 2005 ). Cognitive functioning in siblings discordant for schizophrenia . Acta Psychiatrica. Scandinavica 111 , 185 – 192 .

Kahn , RS , Keefe , RS ( 2013 ). Schizophrenia is a cognitive illness: time for a change in focus . JAMA Psychiatry 70 , 1107 – 1112 .

Korver , N , Quee , PJ , Boos , HB , Simons , CJ , de Haan , L ( 2012 ). Genetic Risk and Outcome of Psychosis (GROUP), a multi-site longitudinal cohort study focused on gene-environment interaction: objectives, sample characteristics, recruitment and assessment methods . International Journal of Methods in Psychiatric Research 21 , 205 – 221 .

Kremen , WS , Faraone , SV , Seidman , LJ , Pepple , JR , Tsuang , MT ( 1998 ). Neuropsychological risk indicators for schizophrenia: a preliminary study of female relatives of schizophrenic and bipolar probands . Psychiatry Research 79 , 227 – 240 .

Leverich , GS , Nolen , WA , Rush , AJ , McElroy , SL , Keck , PE , Denicoff , KD , Suppes , T , Altshuler , LL , Kupka , R , Kramlinger , KG , Post , RM ( 2001 ). The Stanley Foundation Bipolar Treatment Outcome Network. I. Longitudinal methodology . Journal of Affective Disorders 67 , 33 – 44 .

MacCabe , JH ( 2008 ). Population-based cohort studies on premorbid cognitive function in schizophrenia . Epidemiologic Reviews 30 , 77 – 83 .

MacCabe , JH , Lambe , MP , Cnattingius , S , Sham , PC , David , AS , Reichenberg , A , Murray , RM , Hultman , CM ( 2010 ). Excellent school performance at age 16 and risk of adult bipolar disorder: national cohort study . British Journal of Psychiatry 196 , 109 – 115 .

MacCabe , JH , Lambe , MP , Cnattingius , S , Torrang , A , Bjork , C , Sham , PC , David , AS , Murray , RM , Hultman , CM ( 2008 ). Scholastic achievement at age 16 and risk of schizophrenia and other psychoses: a national cohort study . Psychological Medicine 38 , 1133 – 1140 .

Mann-Wrobel , MC , Carreno , JT , Dickinson , D ( 2011 ). Meta-analysis of neuropsychological functioning in euthymic bipolar disorder: an update and investigation of moderator variables . Bipolar Disorders 13 , 334 – 342 .

Martinez-Aran , A , Vieta , E , Reinares , M , Colom , F , Torrent , C , Sanchez-Moreno , J , Benabarre , A , Goikolea , JM , Comes , M , Salamero , M ( 2004 ). Cognitive function across manic or hypomanic, depressed, and euthymic states in bipolar disorder . American Journal of Psychiatry 161 , 262 – 270 .

Maxwell , ME ( 1992 ). Family Interview for Genetic Studies (FIGS): A Manual for FIGS . NIMH: Clinical Neurogenetics Branch : Bethesda, MD .

McClellan , J , Prezbindowski , A , Breiger , D , McCurry , C ( 2004 ). Neuropsychological functioning in early onset psychotic disorders . Schizophrenia Research 68 , 21 – 26 .

McIntosh , AM , Gow , A , Luciano , M , Davies , G , Liewald , DC , Harris , SE , Corley , J , Hall , J , Starr , JM , Porteous , DJ , Tenesa , A , Visscher , PM , Deary , IJ ( 2013 ). Polygenic risk for schizophrenia is associated with cognitive change between childhood and old age . Biological Psychiatry 15 , 938 – 943 .

McIntosh , AM , Harrison , LK , Forrester , K , Lawrie , SM , Johnstone , EC ( 2005 ). Neuropsychological impairments in people with schizophrenia or bipolar disorder and their unaffected relatives . British Journal of Psychiatry 186 , 378 – 385 .

Pachet , AK , Wisniewski , AM ( 2003 ). The effects of lithium on cognition: an updated review . Psychopharmacology (Berlin) 170 , 225 – 234 .

Pirkola , T , Tuulio-Henriksson , A , Glahn , D , Kieseppa , T , Haukka , J , Kaprio , J , Lonnqvist , J , Cannon , TD ( 2005 ). Spatial working memory function in twins with schizophrenia and bipolar disorder . Biological Psychiatry 58 , 930 – 936 .

Psychiatric GWAS Consortium Bipolar Disorder Working Group ( 2011 ). Large-scale genome-wide association analysis of bipolar disorder identifies a new susceptibility locus near ODZ4 . Nature Genetics 43 , 977 – 983 .

Purcell , SM , Wray , NR , Stone , JL , Visscher , PM , O'Donovan , MC , Sullivan , PF , Sklar , P ( 2009 ). Common polygenic variation contributes to risk of schizophrenia and bipolar disorder . Nature 460 , 748 – 752 .

R Core Team ( 2014 ). R: A language and environment for statistical computing, Vienna, Austria ( ). R: A language and environment for statistical computing, Vienna, Austria ( http://www.R-project.org/ ).

Regeer , EJ , Krabbendam , L , De Graaf , R , Have , MT , Nolen , WA , van Os , J ( 2009 ). Berkson's bias and the mood dimensions of bipolar disorder . International Journal of Methods in Psychiatric Research 18 , 279 – 286 .

Reichenberg , A , Harvey , PD , Bowie , CR , Mojtabai , R , Rabinowitz , J , Heaton , RK , Bromet , E ( 2009 ). Neuropsychological function and dysfunction in schizophrenia and psychotic affective disorders . Schizophrenia Bulletin 35 , 1022 – 1029 .

Reichenberg , A , Weiser , M , Rabinowitz , J , Caspi , A , Schmeidler , J , Mark , M , Kaplan , Z , Davidson , M ( 2002 ). A population-based cohort study of premorbid intellectual, language, and behavioral functioning in patients with schizophrenia, schizoaffective disorder, and nonpsychotic bipolar disorder . American Journal of Psychiatry 159 , 2027 – 2035 .

Robinson , LJ , Ferrier , IN ( 2006 ). Evolution of cognitive impairment in bipolar disorder: a systematic review of cross-sectional evidence . Bipolar Disorders 8 , 103 – 116 .

Robinson , LJ , Thompson , JM , Gallagher , P , Goswami , U , Young , AH , Ferrier , IN , Moore , PB ( 2006 ). A meta-analysis of cognitive deficits in euthymic patients with bipolar disorder . Journal of Affective Disorders 93 , 105 – 115 .

Sartorius , N , Gulbinat , W , Harrison , G , Laska , E , Siegel , C ( 1996 ). Long-term follow-up of schizophrenia in 16 countries. A description of the International Study of Schizophrenia conducted by the World Health Organization . Soc. Psychiatry. Psychiatr. Epidemiology 31 , 249 – 258 .

Schizophrenia Psychiatric Genome-Wide Association Study (GWAS) Consortium ( 2011 ). Genome-wide association study identifies five new schizophrenia loci . Nature Genetics 43 , 969 – 976 .

Schubart , CD , van Gastel , WA , Breetvelt , EJ , Beetz , SL , Ophoff , RA , Sommer , IE , Kahn , RS , Boks , MP ( 2011 ). Cannabis use at a young age is associated with psychotic experiences . Psychological Medicine 41 , 1301 – 1310 .

Senturk , V , Goker , C , Bilgic , A , Olmez , S , Tugcu , H , Oncu , B , Atbasoglu , EC ( 2007 ). Impaired verbal memory and otherwise spared cognition in remitted bipolar patients on monotherapy with lithium or valproate . Bipolar Disorders 9 ( Suppl. 1 ), 136 – 144 .

Sheehan , DV , Lecrubier , Y , Sheehan , KH , Amorim , P , Janavs , J , Weiller , E , Hergueta , T , Baker , R , Dunbar , GC ( 1998 ). The Mini-International Neuropsychiatric Interview (M.I.N.I.): the development and validation of a structured diagnostic psychiatric interview for DSM-IV and ICD-10 . Journal of Clinical Psychiatry 59 ( Suppl. 20 ), 22 – 33 .

Suppes , T , Leverich , GS , Keck , PE , Nolen , WA , Denicoff , KD , Altshuler , LL , McElroy , SL , Rush , AJ , Kupka , R , Frye , MA , Bickel , M , Post , RM ( 2001 ). The Stanley Foundation Bipolar Treatment Outcome Network. II. Demographics and illness characteristics of the first 261 patients . Journal of Affective Disorders 67 , 45 – 59 .

Torres , IJ , Boudreau , VG , Yatham , LN ( 2007 ). Neuropsychological functioning in euthymic bipolar disorder: a meta-analysis . Acta Psychiatrica Scandinavica (Suppl.) 116 , 17 – 26 .

Toulopoulou , T , Quraishi , S , McDonald , C , Murray , RM ( 2006 ). The Maudsley Family Study: premorbid and current general intellectual function levels in familial bipolar I disorder and schizophrenia . Journal of Clinical and Experimental Neuropsychology 28 , 243 – 259 .

Trotta , A , Murray , RM , MacCabe , JH ( 2015 ). Do premorbid and post-onset cognitive functioning differ between schizophrenia and bipolar disorder? A systematic review and meta-analysis . Psychological Medicine 45 , 381 – 394 .

van Oel , CJ , Sitskoorn , MM , Cremer , MP , Kahn , RS ( 2002 ). School performance as a premorbid marker for schizophrenia: a twin study . Schizophrenia Bulletin 28 , 401 – 414 .

Vinkers , CH , van Gastel , WA , Schubart , CD , Van Eijk , KR , Luykx , JJ , Van Winkel , R , Joels , M , Ophoff , RA , Boks , MP , Bruggeman , R , Cahn , W , De Haan , L , Kahn , RS , Meijer , CJ , Myin-Germeys , I , van Os , J , Wiersma , D ( 2013 ). The effect of childhood maltreatment and cannabis use on adult psychotic symptoms is modified by the COMT Val158Met polymorphism . Schizophrenia Research 150 , 303 – 311 .

Vonk , R , van der Schot , AC , van Baal , GC , van Oel , CJ , Nolen , WA , Kahn , RS ( 2012 ). Premorbid school performance in twins concordant and discordant for bipolar disorder . Journal of Affective Disorders 136 , 294 – 303 .

Vreeker , A , Van Bergen , AH , Kahn , RS ( 2015 ). Cognitive enhancing agents in schizophrenia and bipolar disorder . European Neuropsychopharmacology 25 , 969 – 1002 .

Wechsler , D ( 1997 ). WAIS-III:Wechsler Adult Intelligence Scale , 3rd edn. Administration and Scoring Manual. Psychological Corporation/Harcourt Brace : San Antonio, TX .

Wing , JK , Babor , T , Brugha , T , Burke , J , Cooper , JE , Giel , R , Jablenski , A , Regier , D , Sartorius , N ( 1990 ). SCAN. Schedules for Clinical Assessment in Neuropsychiatry . Archives of General Psychiatry 47 , 589 – 593 .

Wingo , AP , Wingo , TS , Harvey , PD , Baldessarini , RJ ( 2009 ). Effects of lithium on cognitive performance: a meta-analysis . Journal of Clinical Psychiatry 70 , 1588 – 1597 .

Woodberry , KA , Giuliano , AJ , Seidman , LJ ( 2008 ). Premorbid IQ in schizophrenia: a meta-analytic review . American Journal of Psychiatry 165 , 579 – 587 .