Evid Based Mental Health: first published as 10.1136/ebmental-2019-300100 on 27 June 2019. Downloaded from Original article Relating irritability and suicidal ideation using mood and anxiety Gin Malhi,1,2 Erica Bell, 1,2 Pritha Das,1,2 Tim Outhred1,2 1Sydney Medical School, The ABSTRact University of Sydney, Sydney, Background Suicide is common in the context of Summary box New South Wales, Australia 2 depression and bipolar disorders, but there remains Department of Psychological What is already known about this subject? Medicine, The University of a lack of understanding as to how suicide ideation, a Sydney Northern Clinical School, common symptom of mood disorders, progresses to ► Suicidal ideation is a common feature of mood St Leonards, New South Wales, suicidal behaviour. Irritability, a feature of some types of disorders, particularly depression. Australia depression, is thought to contribute to the development ► Depression is a heterogeneous condition, with of suicidal behaviour, but these associations are not well anxious depression and melancholic depression Correspondence to being two key subtypes. Professor Gin Malhi, University established. Irritability is a common symptom of mood of Sydney Sydney Medical Objective To examine the relationship between ► School, Sydney, NSW 2065, irritability and suicide ideation according to the subtype disorders and is linked to suicidal ideation. Australia; gin. malhi@ sydney. of depression expressed in patients with mood disorder. ► As yet no research has specifically examined edu. au the way in which irritability operates within Methods 75 patients with mood disorders seen at anxious and melancholic subtypes of Received 5 June 2019 the CADE (Clinical Assessment Diagnostic Evaluation) depression to contribute to suicidal ideation. Accepted 17 June 2019 Clinic underwent clinical assessment for suicidal Published Online First ideation (Paykel Suicide Scale), symptom severity (Young 27 June 2019 What are the new findings? Mania Rating Scale (YMRS), Hamilton Rating Scale for ► Within the two depression scales used, Depression (HAM-D) (anxious depression), Montgomery- irritability correlated with items of suicidal Åsberg Depression Rating Scale (MADRS) (melancholic ideation in one scale but not another. depression)) and irritability (item 5 of the YMRS). ► Irritability showed no direct correlation with Findings Interestingly, irritability correlated with mania scores on a measure of suicidal ideation. (r=0.734, p<0.001 (YMRS)) and depressive symptom ► Irritability demonstrated an indirect correlation scores (r=0.369, p<0.001 (MADRS); r=0.477, p<0.001 with suicidal ideation. (HAM-D)), which in turn correlated with suicide ideation ► It appears that the relationship between scores (r=0.364, p<0.01 (MADRS); r=0.275, p=0.017 irritability and suicidal ideation is dependent on (HAM-D)). However, despite this indirect association, the mood context within which it operates. there was no direct correlation between irritability and How might it impact on clinical practice in the suicide ideation (r=0.050, p>0.05). foreseeable future? Conclusions The nature of the relationship between ► These findings suggest that in clinical practice, irritability and suicidal ideation is determined by the http://ebmh.bmj.com/ consideration of the subtype of depression, emotional context within which irritability operates. rather than irritability alone, should be Clinical implications Findings suggest that rather paramount in assessing suicide risk. than examining irritability alone, consideration of the subtype of depression, especially that of anxious depression, should be paramount in assessing suicide risk. value in identifying at-risk individuals.3 But thus far, little discernible impact has been made. on October 2, 2021 by guest. Protected copyright. Given the prevalence of suicidal ideation in mood disorders, a useful strategy in understanding BACKGROUND the role of suicide-related factors is to examine Suicidal ideation is a common feature of mood these thoughts in the context of these illnesses. disorders. It needs to be addressed urgently in This approach also takes advantage of the fact that both clinical settings and in the general population depression is a heterogeneous condition and that because rates of suicide, in developed countries such the relationship of its various subtypes with suicidal as Australia, have remained virtually unchanged for ideation varies accordingly, and therefore by exam- the past 15 years despite extensive research and ining suicidal ideation in the context of depression © Author(s) (or their the best efforts of preventative programmes.1 Even the factors associated with suicidal thinking can be employer(s)) 2019. No 4–6 commercial re-use. See rights more worrisome, the rates of suicide within clinical partitioned. For example, among the subtypes of and permissions. Published populations, such as those with mood disorders, depression, anxious depression appears to confer by BMJ. are significantly higher than the general popula- significantly higher risk for suicide than depres- 4 To cite: Malhi G, Bell E, tion (20–30 times the risk of the general popula- sion in which anxious features are absent. Of 2 Das P, et al. Evid Based tion in bipolar disorder). Hence, considerable note, within this subtype of depression, individual Mental Health resources have been dedicated to determining the syndromes consisting of psychomotor agitation, 2019;22:95–99. key suicide-related factors that may hold predictive restlessness and irritability feature prominently.5 Malhi G, et al. Evid Based Mental Health 2019;22:95–99. doi:10.1136/ebmental-2019-300100 95 Evid Based Mental Health: first published as 10.1136/ebmental-2019-300100 on 27 June 2019. Downloaded from Original article Another subtype of depression that features psychomotor medication changes, or received electroconvulsive therapy or changes is melancholia, which is characterised by low energy, psychotherapy within the preceding month. anhedonia and loss of interest.6 7 Clinically, melancholia Depression was rated using two scales: the 21-item Hamilton contrasts with anxious depression, but suicidal ideation is again Rating Scale for Depression (HAM-D),11 which categorises the a prominent feature. However, importantly, the motivating severity of depression scores as mild (8–13), moderate (14–18), factors driving suicidal ideation and behaviour differ according severe (19–22) and very severe (23+), and the Montgomery-Ås- 8 to depressive subtype. berg Depression Rating Scale (MADRS),12 which rates the Interestingly, even though major depression is clinically indis- severity of depression in patients with mood disorders using tinguishable from depression in bipolar disorder, suicide, which 10 items, and categorises depression as mild (7–19), moderate occurs predominantly in the depressive phase, is more common (20–34) and severe (34+). Of note, although the MADRS typi- in bipolar disorder. Hence mapping the development of suicidal cally correlates highly with scores on the HAM-D, the former is thinking in bipolar disorders—as has been done recently—is typically more attuned to melancholic features of depression— informative and this has led to the identification of some key reflecting a more melancholic subtype and showing greater stages in the process (see Malhi et al3). In the context of bipolar sensitivity to medications13 than the HAM-D, which is gener- disorder, the symptom of suicidal ideation, if unchecked, is liable ally more sensitive to anxiety.5 The use of two depression scales to progress to suicidal behaviours, attempts, and in some cases allowed for comprehensive assessment of the various features completed suicide. This progression is complex and multifaceted, and is currently not completely understood. However, research of depression within the study cohort that contained a variety has noted the differential impact of distal and proximal factors, of mood disorder presentations. Furthermore, using both the which affect the severity of suicidal thoughts and behaviours, HAM-D and the MADRS maximised the possibility of capturing with each factor producing variable impact at different points both anxious and melancholic depressive features in the present along the pathway to suicide. cohort. One such important factor that has gained interest in recent Manic symptoms were rated using the Young Mania Rating 14 years is the symptom of irritability, which has been posited to Scale (YMRS), which comprises 11 items scored either from 0 increase the likelihood of transitioning from suicidal ideation to 4 or from 0 to 8. Thus four items (irritability, speech, thought to suicide attempt in the context of psychiatric disorders.9 content and disruptive/aggressive behaviour) are given twice the Although irritability is primarily considered a symptom of mania weight of other items to compensate for poor cooperation. The and is included in scales measuring manic symptoms, it is during total score extends from 0 to 60, with higher scores indicating depressive episodes of mood disorders that suicidal ideation greater severity. Item 5 of the YMRS was used as a measure of and behaviours are more likely to occur. Furthermore, irrita- irritability in each subject during a clinical interview conducted bility is common to both anxious and melancholic depression, by a psychiatrist as this study examined a clinical population, and is also correlated to suicidal ideation within these clinical whose ratings of irritability required being