Editing Amygdala (section)

===Psychological disorders===
With advances in [[neuroimaging]] technology such as [[MRI]], neuroscientists have made significant findings concerning the amygdala in the human brain. A variety of data shows the amygdala has a substantial role in mental states, and is related to many [[mental illness|psychological disorders]]. Some studies have shown children with [[anxiety disorder]]s tend to have a smaller left amygdala. In the majority of the cases, there was an association between an increase in the size of the left amygdala with the use of [[SSRI]]s (antidepressant medication) or psychotherapy. The left amygdala has been linked to [[social anxiety disorder]], [[Obsessive–compulsive disorder|obsessive and compulsive disorders]], and [[PTSD|post-traumatic stress disorder]] (PTSD), as well as more broadly to separation and [[generalized anxiety disorder]].<ref name="Arehart-Treichel2005">{{cite journal |last1=Arehart-Treichel |first1=Joan |name-list-style=vanc |year=2005 |title=Changes in Children's Amygdala Seen After Anxiety Treatment |journal=Psychiatric News |volume=40 |issue=9 |page=37 |doi=10.1176/pn.40.9.00400037 |issn=0033-2704}}</ref> Multiple studies have found that the amygdalae may be responsible for the emotional reactions of PTSD patients. One study in particular found that when PTSD patients are shown pictures of faces with fearful expressions, their amygdalae tended to have a higher activation than someone without PTSD.<ref>{{cite book |last=Carlson |first=Neil R. |url=https://archive.org/details/physiologybehavi00carl_811 |title=Physiology of Behavior |date=12 January 2012 |publisher=Pearson |isbn=978-0205239399 |page=[https://archive.org/details/physiologybehavi00carl_811/page/n628 608] |url-access=limited |name-list-style=vanc}}</ref>

In 2006, researchers observed [[hyperactivity]] in the amygdala when patients were shown threatening faces or confronted with frightening situations. Patients with severe [[social anxiety disorder|social phobia]] showed a correlation with increased response in the amygdala.<ref name="pmid16256956">{{cite journal |vauthors=Phan KL, Fitzgerald DA, Nathan PJ, Tancer ME |date=March 2006 |title=Association between amygdala hyperactivity to harsh faces and severity of social anxiety in generalized social phobia |journal=Biological Psychiatry |volume=59 |issue=5 |pages=424–9 |doi=10.1016/j.biopsych.2005.08.012 |pmid=16256956 |s2cid=34105191}} [https://www.sciencedaily.com/releases/2006/01/060118205940.htm Lay summary] available from [[Science Daily]].</ref> Individuals with [[psychopathy]] show reduced autonomic responses to instructed fear cues than otherwise healthy individuals.<ref>{{cite journal |vauthors=Blair RJ |date=August 2008 |title=The amygdala and ventromedial prefrontal cortex: functional contributions and dysfunction in psychopathy |journal=Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences |volume=363 |issue=1503 |pages=2557–65 |doi=10.1098/rstb.2008.0027 |pmc=2606709 |pmid=18434283}}</ref> Similarly, depressed patients showed exaggerated left amygdala activity when interpreting emotions for all faces, and especially for fearful faces. This hyperactivity was normalized when patients were administered antidepressant medication.<ref>{{cite journal |vauthors=Sheline YI, Barch DM, Donnelly JM, Ollinger JM, Snyder AZ, Mintun MA |date=November 2001 |title=Increased amygdala response to masked emotional faces in depressed subjects resolves with antidepressant treatment: an fMRI study |journal=Biological Psychiatry |volume=50 |issue=9 |pages=651–8 |doi=10.1016/S0006-3223(01)01263-X |pmid=11704071 |s2cid=8927264}}</ref>

In a 2003 study, subjects with [[borderline personality disorder]] showed significantly greater left amygdala activity than normal control subjects. Some borderline patients even had difficulties classifying neutral faces or saw them as threatening.<ref>{{cite journal |display-authors=8 |vauthors=Donegan NH, Sanislow CA, Blumberg HP, Fulbright RK, Lacadie C, Skudlarski P, Gore JC, Olson IR, McGlashan TH, Wexler BE |date=December 2003 |title=Amygdala hyperreactivity in borderline personality disorder: implications for emotional dysregulation |url=https://wesscholar.wesleyan.edu/cgi/viewcontent.cgi?article=1193&context=div3facpubs |journal=Biological Psychiatry |volume=54 |issue=11 |pages=1284–93 |doi=10.1016/S0006-3223(03)00636-X |pmid=14643096 |s2cid=7493725}}</ref> The amygdala has been observed to respond differently in people with [[bipolar disorder]]. Amygdala dysfunction during face emotion processing is well-documented in bipolar disorder. Individuals with bipolar disorder showed greater amygdala activity (especially the amygdala/medial-prefrontal-cortex circuit).<ref>{{cite journal |vauthors=Thomas LA, Kim P, Bones BL, Hinton KE, Milch HS, Reynolds RC, Adleman NE, Marsh AA, Blair RJ, Pine DS, Leibenluft E |date=January 2013 |title=Elevated amygdala responses to emotional faces in youths with chronic irritability or bipolar disorder |journal=NeuroImage: Clinical |volume=2 |issue=2 |pages=637–645 |doi=10.1016/j.nicl.2013.04.007 |pmc=3746996 |pmid=23977455}}</ref><ref>{{cite journal |vauthors=Keener MT, Fournier JC, Mullin BC, Kronhaus D, Perlman SB, LaBarbara E, Almeida JC, Phillips ML |date=September 2012 |title=Dissociable patterns of medial prefrontal and amygdala activity to face identity versus emotion in bipolar disorder |journal=Psychological Medicine |volume=42 |issue=9 |pages=1913–24 |doi=10.1017/S0033291711002935 |pmc=3685204 |pmid=22273442}}</ref> For people with manic [[bipolar I disorder]], a decreased negative functional connectivity between the [[orbitofrontal cortex]] and the amygdala was also observed.<ref>{{Cite journal |last=Foland |first=Lara C. |last2=Altshuler |first2=Lori L. |last3=Bookheimer |first3=Susan Y. |last4=Eisenberger |first4=Naomi |last5=Townsend |first5=Jennifer |last6=Thompson |first6=Paul M. |date=2008 |title=Evidence for deficient modulation of amygdala response by prefrontal cortex in bipolar mania |url=https://doi.org/10.1016/j.pscychresns.2007.04.007 |journal=Psychiatry Research: Neuroimaging |volume=162 |issue=1 |pages=27–37 |doi=10.1016/j.pscychresns.2007.04.007 |issn=0925-4927|pmc=2410029 }}</ref> A 2003 study found that adult and adolescent bipolar patients tended to have considerably smaller amygdala volumes and somewhat smaller [[hippocampus|hippocampal]] volumes.<ref>{{cite journal |vauthors=Blumberg HP, Kaufman J, Martin A, Whiteman R, Zhang JH, Gore JC, Charney DS, Krystal JH, Peterson BS |date=December 2003 |title=Amygdala and hippocampal volumes in adolescents and adults with bipolar disorder |journal=Archives of General Psychiatry |volume=60 |issue=12 |pages=1201–8 |doi=10.1001/archpsyc.60.12.1201 |pmid=14662552 |doi-access=}}</ref> Many studies have also focused on the connections between the amygdala and [[autism]].<ref>{{cite journal |vauthors=Schultz RT |year=2005 |title=Developmental deficits in social perception in autism: the role of the amygdala and fusiform face area |journal=International Journal of Developmental Neuroscience |volume=23 |issue=2–3 |pages=125–41 |doi=10.1016/j.ijdevneu.2004.12.012 |pmid=15749240 |s2cid=17078137}}</ref>