Executive Dysfunction

Conditions with impaired Executive Function:

• Anxiety Disorders (disputed)
  • little research, conflicting results. Shifting & inhibition has and has not been found. Panic disorder has found impaired visuospatial WM, in GAD impaired verbal WM but not maintenance (read
    10.1016/j.brat.2009.01.017 &
    10.1037/0033-2909.133.1.1 for more)
  • little research on verbal fluency, 1 study reported impaired phonemic verbal fluency in panic disorder, others found no impairment in GAD or SAD- but more research needed²
• Attention Deficit Hyperactivity Disorder^1–3 (ADHD)
  • impairments in shifting, inhibition, visuospatial WM, verbal WM manipulation (small to medium effect sizes), verbal WM maintenance (small effect size). Updating hasn’t been widely studied in ADHD.²
  • semantic verbal fluency impairment (small effect), with larger effect for phonemic²
  • Planning impairments (one medium effect size, one study had small)²
• Autism Spectrum Disorder/Condition³ (ASD)
  • Inhibition, initiate, Working memory, planning, organization, monitoring⁴
• Bipolar² (BD, BPD)
  • “somewhat larger impairments than depressives” “relatively uniformly impaired across EF domains, with medium effect sizes for shifting, inhibition, visuospatial WM and verbal WM manipulation, and small but significant effect for verbal WM maintanence.” Little research on updating + BPD.²
  • semantic verbal fluency impairment (medium effect)
    (somewhat smaller effect for phonemic verbal fluency, tho still significant) ²
  • significant impairments in planning²
  • “Slightly less severe but nonetheless consistent cross-domain deficits” found in BPD⁵
  • EF “deficits are present regardless of mood state but are likely more pronounced during acute depression or mania.”⁵
    
• Childhood Adversity
• Conduct Disorders^1,2
  • may be at least partially accounted for be co-occuring ADHD²
• Eating Disorders⁶
  • Bulimic-Spectrum EDs (AN binge-purge subtype, Bulimia Nervosa, Binge-Eating Disorder): Inhibition deficits (likely proactive inhibition moreso than reactive behavioral inhibition.) This is most true (some studies suggest specifically related to) for disorder-relevant stimuli (food or body-related). ⁶
  • “BED may be associated with ED-specific rather than general inhibitory control impairments.”It is also not clear whether BED status is associated with additional inhibitory control deficits beyond what is seen in obesity”⁶
  • Poor set-shifting has been suggested to “contribute to rigid and compulsive behaviors” in AN.⁶
  • Poor set-shifting with medium effect sizes found in AN-R, BN & BED, but not AN-BP (small effect size)⁶
  • “Set-shifting deficits in AN reamin after controlling for depressive symptoms”⁶
  • Poor central coherence found in EDs, esp AN (thus they focus more on details like body weight over bigger picture things like more comprehensive sense of self.)⁶
  • Attentional bias, especially for disorder-salient stimuli⁶
  • Some early evidence for WM deficits across EDs but more research is needed⁶
  • Body dysmorphic Disorder (not technically an eating disorder?…) had deficits in set-shifting and visuospatial organization. ( 10.1016/j.psychres.2017.11.062 )

• Korsakoff’s Syndrome (KS)⁷
  • Poor planning, shifting, working memory updating, but contradictory results re: inhibition deficits⁷
  • shifting and updating most effected ⁷
• Learning Disorders (LDs)⁸
  • Developmental dyslexia associated with inhibition and updating deficits, but not switching (tho all results seem to have contradictory studies going both ways). (high predictive relationships between scores and liklihood of diagnosis of developmental dyslexia & poorer reading ability)⁸
• Major Depressive Disorder^1,2 (MDD)
  • significantly impaired, w/small-to-medium effect sizes on shifting, inhibition, updating & WM.²
  • largest deficit: semantic verbal fluency task (medium effect size) (somewhat smaller effect for phonemic verbal fluency, tho still significant) ²
  • significant impairments in planning ²
  • “Unipolar depression showed the same pattern” as schizophrenia, but less severe- with medium effect sizes across all domains but with lesser impairment of WM maintenance. ⁵
  • EFs deficits have not been shown to improve after symptom remission ⁵
  • EF “deficits were more pronounced the more chronic the depression” (“rather than relating to symptom severity or prior antidepressant trial failures”) ⁵
  • Depressives currently experiencing symptoms were found to have inhibition difficulties (but not shifting difficulties), whereas those who were not currently in a depressive state had the opposite, shifting deficits but not inhibition. current depressive state folks had more math errors on a plus-minus task, “suggesting that those experiencing current symptoms/distress exhibited a speed-accuracy tradoff.” ⁹
  • Inhibition deficits being found with current but not past symptoms “suggests that inhibition deficits may vary as a function of symptoms/distress.”⁹
  • That shifting deficits remain even when there are only past, not current symptoms, “is consistent with other evidence for a unique link between depression and deficits in shifting.” Though it’s not known if shifting deficits make one vulnerable to depression, or if experiencing depression causes future shifting difficulties (“Scar hypothesis).⁹
• Mood Disorders²
  • “shifting, inhibition, updating, visuospatial WM, verbal manipulation, and .. simple verbal WM maintenance” (but these are “somewhat smaller” deficits than found in schizophrenia)³
  • “For example, rumination is associated with better performance on an EF task requiring goal maintenance (stability) but worse performance on an EF task requiring rapid shifting (flexibility; Altamirano et al., 2010),”²
  • Executive function neurocircuts “are likely recruited in the service of symptom regulation.”⁵
• Obsessive Compulsive Disorder^1,2 (OCD)
  • imapired EF, “w/small but significant effect sizes for shifting, inhibition, visuospatial WM & verbal WM manipulation, but a large effect size for updating.” “simple WM maintenance appears to be unimpaired.” EF deficits *do not* originate from co-occuring depression²
  • semantic & phonemic verbal fluency impairment (small effect) ²
  • Planning impairments (2 small effect studies, one medium)²
  • largest deficit in updating²
• Oppositional Defiance Disorder (ODD)²
  • may be at least partially accounted for be co-occuring ADHD ²

• Personality Disorders
  • Antisocial Personality Disorder (ASPD) related to Common EF deficits, no relation to shifting¹⁰
• Phenylketonuria³
• Post-Traumatic Stress Disorder (PTSD)
  • impaired shifting (medium effect), visuospatial WM (small effect), inhibition. co-occuring *may* account for EF deficits in PTSD, more research is needed.²
  • inconsistant evidence for verbal fluency as well as planning ²
• Schizophrenia¹
  • Largest EF deficits²
  • Largest effect on “shifting, inhibition, updating, visuospatial WM, verbal manipulation, and a medium effect size for simple verbal WM maintenance”²
  • largest deficit: semantic verbal fluency task (large effect size) (somewhat smaller effect for phonemic verbal fluency, tho still significant)²
• Substance Use Disorders^1,2
  • deficit in response inhibition: cocaine, MDMA, methamphetamine, tobacco, alcohol (but not opioids or cannabis)²
  • deficits in shifting & inhibition: cocaine
  • deficits in shifting, inhibition & WM across most substance use disorders, generally medium effect sizes (tho a meta-analysis found no deficits on a composite of inhibition and shifting for chronic opioid users and only very small effect for MDMA use.)²
  • Hard to tell what is a cause or consequence, but at least for some, like heavy drinking, impaired EFs are probably both^2,5
  • Deficits “foremost in inhibition, but also shifting and working memory” ⁵
  • EF deficits “were typically moderate up to one year of abstinence” and then lessened as the abstinence time increased. ⁵
• Tourette’s Syndrome³
  • Deficits in response inhibition, set-shifting, sustained attention. (10.1177/1087054714545536)

Executive functions have been called the “canary in the coal mine” for overall mental and physical health. They are “the first to suffer, and suffer disproportionately, if something is not right in your life.”¹ This includes if you are” stressed, sad, lonely, sleep deprived, or not physically fit.” ^{further citations for each can be found at 1}