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    <p class="ltrs-br-ltr-br-title"><span class="bold">Insomnia Severity Is Associated With Decreased Executive Functioning in Patients With Suicidal Ideation and Drug Abuse</span></p>
    <p class="ltrs-br-ltr-br-body-text"><span class="semibold">To the Editor:</span> Insomnia has been associated with decreased executive functioning in those without substance use disorders.<span class="htm-cite"><a href="#ref1">1</a></span> Although numerous studies have linked impulsivity with substance abuse and suicidal ideation, its relationship with insomnia in the substance-abusing population is unclear.<span class="htm-cite"><a href="#ref2">2–6</a></span> In this preliminary study, we explore the relationship of insomnia severity with objective and subjective impulsivity measured by computerized behavioral tests and a self-report questionnaire, respectively, in patients with suicidal ideation/behavior attending a psychiatric emergency department. We hypothesized that a higher insomnia severity would be associated with increased objective impulsivity (a decrease in executive functioning) and higher subjective impulsivity scores.</p>
    <p class="ltrs-br-ltr-br-body-text">&nbsp;</p>
    <p class="ltrs-br-ltr-br-body-text"><span class="semibold-ital">Method</span><span class="semibold">.</span> This investigation involved secondary analyses of cross-sectional data from an ongoing study (N.S., J.L.E., unpublished data, 2012). Subjects were adults (N<span class="thinspace"> </span>=<span class="thinspace"> </span>21, ≤<span class="thinspace"> </span>65 years of age) who presented with suicidal ideation/behavior between July 2012 and December 2012 to the emergency department, where they were observed until their symptoms stabilized. We excluded patients with any motor response, visual or hearing disorders, psychotic symptoms, or inability to read or comprehend English. The instruments used in this study included the following: </p>
    <p class="ltrs-br-ltr-br-offset">1. The Stop-Signal Reaction-Time Task,<span class="htm-cite"><a href="#ref7">7</a></span> which assesses objective impulsivity through response inhibition (a facet of executive functioning) based on correct responses and reaction times<span class="htm-cite"><a href="#ref7">7</a>,<a href="#ref8">8</a></span>; </p>
    <p class="ltrs-br-ltr-br-offset">2. The UPPS Impulsive Behavior Scale,<span class="htm-cite"><a href="#ref9">9</a></span> which is a 45-item self-report measure that assesses personality aspects of subjective impulsivity (the “S” sensation-seeking component was excluded in this protocol); </p>
    <p class="ltrs-br-ltr-br-offset">3. The sleep question from the Center for Epidemiology Studies-Depression Scale (CES-D),<span class="htm-cite"><a href="#ref10">10</a></span> which assesses insomnia by inquiring, “Over last week, my sleep was restless….” with the responses arrayed as “less than a day,” “1–2 days,” “3–4 days,” and “5–7 days.” The responses were categorized into “frequent” (ie, those with restless sleep for ≥<span class="thinspace"> </span>5 nights/wk) or “infrequent” (those with ≤<span class="thinspace"> </span>4 nights/wk) insomnia on the basis of the distribution of responses, clinical significance, and similarity to analyses from prior literature<span class="htm-cite"><a href="#ref11">11</a></span>; </p>
    <p class="ltrs-br-ltr-br-offset">4. The remaining CES-D items, which assess depressive symptoms. </p>
    <p class="ltrs-br-ltr-br-body-text">The institutional review board approved the study, and subjects signed informed consent prior to participation.</p>
    <p class="ltrs-br-ltr-br-body-text"><span class="semibold-ital">Results</span><span class="semibold">.</span> The demographic variables included the following: the mean age was 38.3 (SD<span class="thinspace"> </span>=<span class="thinspace"> </span>10.1) years, 18 (85.7%) identified themselves as African American, 18 (85.7%) were male, 9 (42.9%) were single, 16 (76.2%) were unemployed, 8 (38.1%) had ≥<span class="thinspace"> </span>12 years of education, and 12 (57.1%) reported being homeless. Urine drug screens at admission were positive in 14 (66.7%) for cocaine, 6 (28.6%) for cannabis, 5 (23.8%) for phencyclidine, 4 (19.0%) for sedative-hypnotic medications, and 3 (14.3%) for opioids. Four subjects (19.0%) reported use of only 1 drug (cocaine).</p>
    <p class="ltrs-br-ltr-br-body-text">Subjects with frequent insomnia had significantly higher CES-D scores. In analyses adjusted for demographic and mood covariates, those with frequent insomnia (as compared to those with infrequent insomnia) had a significantly decreased number of correct responses and a higher mean reaction time at 160 ms. Similarly, a higher reaction time was seen at 320 ms for this group, although this was not statistically significant. Those with frequent insomnia (in comparison to those with infrequent insomnia) had nonsignificantly lower scores on the UPPS impulsivity scales (see <span class="callout"><a href="#" onclick="createFigure('t1'); return false;">Table 1</a></span>).</p>
    <div id="figure" class="right"> <a href="#" onclick="createFigure('t1'); return false;"><img src="13l01548t1.gif" alt="Table 1" id="t1" border="0" /></a>
      <p class="click-to-enlarge">Click figure to enlarge</p>
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    <p class="ltrs-br-ltr-br-body-text">&nbsp;</p>
    <p class="ltrs-br-ltr-br-body-text">The limitations associated with this preliminary study include the lack of a formal standardized insomnia rating instrument, the small sample size, and its cross-sectional nature. Despite the limitations, we observed that frequent sleep impairment was associated with a lower response inhibition on the Stop Signal Reaction Time Task without any difference in the personality aspects of impulsivity in this complex sample. These results suggest that improving sleep in this population might help improve mood and executive functioning and thus reduce the likelihood of behaviors precipitating visits to the emergency department. Future studies should assess for subjective and objective insomnia using standardized instruments and expand the range of impulsivity facets being assessed.</p>
    <p class="ltrs-br-ltr-br-references-head"><span class="smallcaps">References</span></p>
    <p class="references-references-text-1-9"><a name="ref1"></a>1. Fortier-Brochu E, Beaulieu-Bonneau S, Ivers H, et al. Insomnia and <br />
      daytime cognitive performance: a meta-analysis. <span class="italic">Sleep Med Rev</span>. 2012;16(1):83–94. <span class="pubmed-crossref"><a href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=21636297&dopt=Abstract">PubMed</a> <a href="http://dx.doi.org/10.1016/j.smrv.2011.03.008">doi:10.1016/j.smrv.2011.03.008</a></span></p>
    <p class="references-references-text-1-9"><a name="ref2"></a>2. Albein-Urios N, Martinez-Gonzalez JM, Lozano O, et al. Negative <br />
      urgency, disinhibition and reduced temporal pole gray matter <br />
      characterize the comorbidity of cocaine dependence and personality disorders [published online ahead of print March 2, 2013]. <span class="italic">Drug <br />
      Alcohol Depend</span>. <span class="pubmed-crossref"><a href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=23466222&dopt=Abstract">PubMed</a> <a href="http://www.sciencedirect.com/science/article/pii/S0376871613000574">doi:10.1016/j.drugalcdep.2013.02.008</a></span></p>
    <p class="references-references-text-1-9"><a name="ref3"></a>3. Moshier SJ, Ewen M, Otto MW. Impulsivity as a moderator of the intention-behavior relationship for illicit drug use in patients undergoing treatment. <span class="italic">Addict Behav</span>. 2013;38(3):1651–1655. <span class="pubmed-crossref"><a href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=23254213&dopt=Abstract">PubMed</a> <a href="http://dx.doi.org/10.1016/j.addbeh.2012.09.008">doi:10.1016/j.addbeh.2012.09.008</a></span></p>
    <p class="references-references-text-1-9"><a name="ref4"></a>4. Swann AC, Dougherty DM, Pazzaglia PJ, et al. Increased impulsivity associated with severity of suicide attempt history in patients with bipolar disorder. <span class="italic">Am J Psychiatry</span>. 2005;162(9):1680–1687. <span class="pubmed-crossref"><a href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=16135628&dopt=Abstract">PubMed</a> <a href="http://dx.doi.org/10.1176/appi.ajp.162.9.1680">doi:10.1176/appi.ajp.162.9.1680</a></span></p>
    <p class="references-references-text-1-9"><a name="ref5"></a>5. Gorlyn M. Impulsivity in the prediction of suicidal behavior in adolescent populations. <span class="italic">Int J Adolesc Med Health</span>. 2005;17(3):205–209. <span class="pubmed-crossref"><a href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=16231471&dopt=Abstract">PubMed</a> <a href="http://dx.doi.org/10.1515/IJAMH.2005.17.3.205">doi:10.1515/IJAMH.2005.17.3.205</a></span></p>
    <p class="references-references-text-1-9"><a name="ref6"></a>6. Grano NK-JL, Kouvonen A, Puttoneon S, et al. Association of impulsivity with sleep duration and insomnia in an employee population. <span class="italic">Pers Individ Dif</span>. 2007;43(2):307–318. <span class="pubmed-crossref"><a href="http://dx.doi.org/10.1016/j.paid.2006.11.022">doi:10.1016/j.paid.2006.11.022</a></span></p>
    <p class="references-references-text-1-9"><a name="ref7"></a>7. Evenden JL. <span class="italic">One Choice Stop Signal Task</span> [computer program]. <a href="http://www.wiltonlogic.com/products/imp/ocss.html">http://www.wiltonlogic.com/products/imp/ocss.html</a>. Media, PA: WiltonLogic; 2012.</p>
    <p class="references-references-text-1-9"><a name="ref8"></a>8. Logan GD, Cowan WB. On the ability to inhibit thought and action: a theory of an act of control. <span class="italic">Psychol Rev</span>. 1984;91(3):295–327. <span class="pubmed-crossref"><a href="http://dx.doi.org/10.1037/0033-295X.91.3.295">doi:10.1037/0033-295X.91.3.295</a></span></p>
    <p class="references-references-text-1-9"><a name="ref9"></a>9. Whiteside SP, Lynam DR, Miller JD, et al. Validation of the UPPS impulsive behavior scale: a four factor model of impulsivity. <span class="italic">Eur J Pers.</span> 2005;19(7):559–574. <span class="pubmed-crossref"><a href="http://dx.doi.org/10.1002/per.556">doi:10.1002/per.556</a></span></p>
    <p class="references-references-text-10-99"><a name="ref10"></a>10. Radloff LS. The CES-D Scale: a self-report depression scale for research in the general population. <span class="italic">Appl Psychol Meas.</span> 1977;1(3):385–401. <span class="pubmed-crossref"><a href="http://dx.doi.org/10.1177/014662167700100306">doi:10.1177/014662167700100306</a></span></p>
    <p class="references-references-text-10-99"><a name="ref11"></a>11. Bonnet MH, Arand DL. Clinical effects of sleep fragmentation versus sleep deprivation. <span class="italic">Sleep Med Rev</span>. 2003;7(4):297–310. <span class="pubmed-crossref"><a href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=14505597&dopt=Abstract">PubMed</a> <a href="http://dx.doi.org/10.1053/smrv.2001.0245">doi:10.1053/smrv.2001.0245</a></span></p>
    <p class="ltrs-br-ltr-br-author"><span class="bold">Ninad S. Chaudhary, MBBS, MPH</span></p>
    <p class="ltrs-br-ltr-br-author"><a href="mailto:ninadchaudhary@gmail.com">ninadchaudhary@gmail.com</a> </p>
    <p class="ltrs-br-ltr-br-author"><span class="bold">Subhajit Chakravorty, MD</span></p>
    <p class="ltrs-br-ltr-br-author"><span class="bold">John L. Evenden, PhD</span></p>
    <p class="ltrs-br-ltr-br-author"><span class="bold">Neil Sanuck, MD</span></p>
    <p class="ltrs-br-ltr-br-endmatter-fieldnotes"><span class="semibold-ital">Author affiliations:</span> Department of Public Health, West Chester University of Pennsylvania, West Chester (Dr Chaudhary); Department of Behavioral Sleep Medicine, Perelman School of Medicine of the University of Pennsylvania, Philadelphia (Dr Chaudhary and Dr Chakravorty); Department of Psychiatry, Temple University School of Medicine, Philadelphia (Drs Evenden and Sanuck); WiltonLogic LLC, Media (Dr Evenden); and Department of Psychiatry, Philadelphia Veterans Affairs Medical Center, Philadelphia (Dr Chakavorty), Pennsylvania.</p>
    <p class="ltrs-br-ltr-br-endmatter-fieldnotes"><span class="semibold-ital">Potential conflicts of interest:</span> Dr Evenden is an employee of WiltonLogic LLC and has served on the speakers or advisory boards for H Lundbeck A/S. Drs Chaudhary, Chakravorty, and Sanuck report no potential conflict of interest relevant to the subject of this letter. </p>
    <p class="ltrs-br-ltr-br-endmatter-fieldnotes"><span class="semibold-ital">Funding/support:</span> None reported.</p>
    <p class="ltrs-br-ltr-br-endmatter-fieldnotes"><span class="semibold-ital">Published online:</span> October 31, 2013.</p>
    <p class="ltrs-br-ltr-br-copyright-doi"><span class="italic">Prim Care Companion CNS Disord 2013;15(5):</span><span class="doi">doi:10.4088/PCC.13l01548</span></p>
    <p class="ltrs-br-ltr-br-copyright-doi"><span class="italic">© Copyright 2013 Physicians Postgraduate Press, Inc.</span></p>
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