Suicide in bipolar disorder in a national English sample, 1996-2009: frequency, trends and characteristics

Sex Differences in Brain Disorders

A remarkable feature of the brain is its sexual dimorphism. Sexual dimorphism in brain structure and function is associated with clinical implications documented previously in healthy individuals but also in those who suffer from various brain disorders. Sex-based differences concerning some features such as the risk, prevalence, age of onset, and symptomatology have been confirmed in a range of neurological and neuropsychiatric diseases. The mechanisms responsible for the establishment of sex-based differences between men and women are not fully understood. The present paper provides up-to-date data on sex-related dissimilarities observed in brain disorders and highlights the most relevant features that differ between males and females. The topic is very important as the recognition of disparities between the sexes might allow for the identification of therapeutic targets and pharmacological approaches for intractable neurological and neuropsychiatric disorders.

Suicidal behavior across a broad range of psychiatric disorders

Suicide is a leading cause of death worldwide. In 2020, some 12.2 million Americans seriously contemplated suicide, 3.2 million planned suicide attempts, and 1.2 million attempted suicide. Traditionally, the approach to treating suicidal behavior (SB) has been to treat the "underlying" psychiatric disorder. However, the number of diagnoses associated with SB is considerable. We could find no studies describing the range of disorders reported to be comorbid with SB. This narrative review summarizes literature documenting the occurrence of SB across the lifespan and the full range of psychiatric diagnoses, not only BPD and those that comprise MDE, It also describes the relevance of these observations to clinical practice, research, and nosology. The literature searches contained the terms "suicid*" and each individual psychiatric diagnosis and identified 587 studies. We did not include case reports, case series, studies only addressing suicidal ideation or non-suicidal self-injury (NSSI), studies on self-harm, not distinguishing between SB and NSSI and studies that did not include any individuals that met criteria for a specific DSM-5 diagnosis (n = 366). We found that SB (suicide and/or suicide attempt) was reported to be associated with 72 out of 145 diagnoses, although data quality varied. Thus, SB is not exclusively germane to Major Depressive Episode (MDE) and Borderline Personality Disorder (BPD), the only conditions for which it is a diagnostic criterion. That SB co-occurs with so many diagnoses reinforces the need to assess current and past SB regardless of diagnosis, and supports the addition of charting codes to the DSM-5 to indicate current or past SB. It also comports with new data that specific genes are associated with SB independent of psychiatric diagnoses, and suggests that SB should be managed with specific suicide prevention interventions in addition to treatments indicated for co-occurring diagnoses. SB diagnostic codes would help researchers and clinicians document and measure SB's trajectory and response to treatment over time, and, ultimately, help develop secondary and tertiary prevention strategies. As a separate diagnosis, SB would preclude situations in which a potentially life-threatening behavior is not accounted for by a diagnosis, a problem that is particularly salient when no mental disorder is present, as is sometimes the case.

Rates and associations of relapse over 5 years of 2649 people with bipolar disorder: a retrospective UK cohort study

BACKGROUND

Evidence regarding the rate of relapse in people with bipolar disorder (BD), particularly from the UK, is lacking. This study aimed to evaluate the rate and associations of clinician-defined relapse over 5 years in a large sample of BD patients receiving routine care from a UK mental health service.

METHOD

We utilised de-identified electronic health records to sample people with BD at baseline. Relapse was defined as either hospitalisation, or a referral to acute mental health crisis services, between June 2014 and June 2019. We calculated the 5-year rate of relapse and examined the sociodemographic and clinical factors that were independently associated with relapse status and the number of relapses, over the 5-year period.

RESULTS

Of 2649 patients diagnosed with BD and receiving care from secondary mental health services, 25.5% (n = 676) experienced at least one relapse over 5 years. Of the 676 people who relapsed, 60.9% experienced one relapse, with the remainder experiencing multiple relapses. 7.2% of the baseline sample had died during the 5-year follow-up. Significant factors associated with experiencing any relapse, after adjustment for relevant covariates, were history of self-harm/suicidality (OR 2.17, CI 1.15-4.10, p = 0.02), comorbidity (OR 2.59, CI 1.35-4.97, p = 0.004) and psychotic symptoms (OR 3.66, CI  1.89-7.08, p < 0.001). Factors associated with the number of relapses over 5 years, after adjustment for covariates, were self-harm/suicidality (β = 0.69, CI 0.21-1.17, p = 0.005), history of trauma (β = 0.51, CI = 0.07-0.95, p = 0.03), psychotic symptoms (β = 1.05, CI 0.55-1.56, p < 0.001), comorbidity (β = 0.52, CI 0.07-1.03, p = 0.047) and ethnicity (β = - 0.44, CI - 0.87 to - 0.003, p = 0.048).

CONCLUSIONS

Around 1 in 4 people with BD in a large sample of people with BD receiving secondary mental health services in the UK relapsed over a 5-year period. Interventions targeting the impacts of trauma, suicidality, presence of psychotic symptoms and comorbidity could help to prevent relapse in people with BD and should be considered in relapse prevention plans.

Predictive factors of nonfatal self-harm among community-dwelling older adults assessed for support services

BACKGROUND

Older adults receiving support services are a population at risk for self-harm due to physical illness and functional impairment, which are known risk factors. This study aims to investigate the relative importance of predictive factors of nonfatal self-harm among older adults assessed for support services in New Zealand.

METHODS

interRAI-Home Care (HC) national data of older adults (aged ≥ 60) were linked to mortality and hospital discharge data between January 1, 2012 and December 31, 2016. We calculated the crude incidence of self-harm per 100,000 person-years, and gender and age-adjusted standardized incidence ratios (SIRs). The Fine and Gray competing risk regression model was fitted to estimate the hazard ratio (HR; 95% CIs) of self-harm associated with various demographic, psychosocial, clinical factors, and summary scales.

RESULTS

A total of 93,501 older adults were included. At the end of the follow-up period, 251 (0.27%) people had at least one episode of nonfatal self-harm and 36,333 (38.86%) people died. The overall incidence of nonfatal self-harm was 160.39 (95% CI, 141.36-181.06) per 100,000 person-years and SIR was 5.12 (95% CI, 4.51-5.78), with the highest incidence in the first year of follow-up. Depression diagnosis (HR, 3.02, 2.26-4.03), at-risk alcohol use (2.38, 1.30-4.35), and bipolar disorder (2.18, 1.25-3.80) were the most significant risk factors. Protective effects were found with cancer (0.57, 0.36-0.89) and severe level of functional impairment measured by Activities of Daily Living (ADL) Hierarchy Scale (0.56, 0.35-0.89).

CONCLUSION

Psychiatric factors are the most significant predictors for nonfatal self-harm among older adults receiving support services. Our results can be used to inform healthcare professionals for timely identification of people at high risk of self-harm and the development of more efficient and targeted prevention strategies, with specific attention to individuals with depression or depressive symptoms, particularly in the first year of follow-up.

Directly or Indirectly? The Role of Social Support in the Psychological Pathways Underlying Suicidal Ideation in People with Bipolar Disorder

Contemporary theories of suicide, such as the Schematic Appraisals Model (SAMS), hypothesize that negative perceptions of social support are implicated in the pathways to suicidal experiences. The SAMS predicts that perceived social support influences suicidal ideation through appraisals of defeat and entrapment. However, such pathways have not been investigated in people who have bipolar disorder. This prospective four-month study tested the influence of perceived social support on later suicidal ideation via changes in defeat, entrapment, and hopelessness, in a sample of eighty euthymic participants with bipolar disorder (N = 62 at follow-up). Linear regression models tested the extent to which perceived social support at baseline predicted changes in suicidal ideation at four months directly and indirectly via changes in defeat, entrapment, and hopelessness. Perceived social support did not directly predict changes in suicidal ideation, but there was a significant indirect mediational pathway between perceived social support at baseline and changes in suicidal ideation over time, via changes in defeat, entrapment and hopelessness, supporting the SAMS. Psychological interventions which target negative perceptions of social support early, in tandem with addressing defeat, entrapment, and hopelessness over time, present a potentially effective approach to counter suicidal ideation in people who experience bipolar disorder.

Psychological Resilience to Suicidal Experiences in People with Non-Affective Psychosis: A Position Paper

It is important to understand the psychological factors which underpin pathways to suicidal experiences. It is equally as important to understand how people develop and maintain resilience to such psychological factors implicated in suicidal experiences. Exploring optimal routes to gaining this understanding of resilience to suicidal thoughts and acts in people with severe mental health problems, specifically non-affective psychosis, was the overarching aim of this position paper. There are five central suggestions: 1. investigating resilience to suicidal experiences has been somewhat over-looked, especially in those with severe mental health problems such as schizophrenia; 2. it appears maximally enlightening to use convergent qualitative, quantitative and mixed research methods to develop a comprehensive understanding of resilience to suicide; 3. relatedly, involving experts-by-experience (consumers) in suicide research in general is vital, and this includes research endeavours with a focus on resilience to suicide; 4. evidence-based models of resilience which hold the most promise appear to be buffering, recovery and maintenance approaches; and 5. there is vast potential for contemporary psychological therapies to develop and scaffold work with clients centred on building and maintaining resilience to suicidal thoughts and acts based on different methodological and analytical approaches which involve both talking and non-talking approaches.

Association between lithium levels in drinking water and suicide rates: Role of affective disorders

OBJECTIVE

The study aimed to assess the association between lithium levels in drinking water from public supplies and suicide rates in different municipalities of Lithuania in relation with incidence of affective disorders.

METHODS

53 drinking water samples were analysed from the main public drinking water systems of the country's municipalities. Lithium levels were determined using the ion chromatography method. Information on all registered affective disorders across all age groups and gender within the 5-year period was obtained from the Department of Statistics, and was averaged across the investigation time period. For the statistical analysis, lithium levels were averaged per municipality and plotted against suicide standardized mortality rates per 100,000 populations, within the 5-year period.

RESULTS

We found that lithium levels in drinking water are positively associated with the incidence of affective disorders. Our findings suggest higher incidence rates of affective disorders in the municipalities with a lithium level in drinking water above median compared to those in the municipalities with a lithium level below median and with the same socio-demographic and psychiatric characteristics. Suicide mortality rates are inversely associated with lithium levels in drinking water only in municipalities with higher lithium levels (above median) and with a high rate of affective disorders.

CONCLUSION

Based on our study results and insights we generate the following hypothesis for the further research, that lithium level in drinking water might have an important protective effect against suicide rates in the population with affective disorders.

Sex Differences in Bipolar Disorders: Impact on Psychopathological Features and Treatment Response

INTRODUCTION

Sex differences were demonstrated in bipolar disorders (BD) concerning epidemiological, clinical, and psychopathological characteristics, but consensus is lacking. Moreover, data concerning the influence of sex on treatment response in BD is contrasting. The present cross-sectional study aimed to analyze sex differences in a population of BD subjects, with specific focus on psychopathological features and treatment response.

MATERIALS AND METHODS

Subjects diagnosed with BD according to the Diagnostic and Statistical Manual of Mental Disorders, 5th version (DSM-5) were recruited. Socio-demographic and clinical characteristics were collected. The Hamilton Rating Scale for Depression, the Mania Rating Scale (MRS), the brief version of the Temperament Evaluation of Memphis, Pisa and San Diego-Münster version (briefTEMPS-M), and the Barratt Impulsiveness Scale-11 items (BIS-11) were used for psychopathological assessment. Treatment response was appraised with the Alda Scale. We performed bivariate analyses to compare socio-demographic, clinical, and psychopathological characteristics between men and women (p < 0.05). A logistic regression was run to analyze features that were significantly associated with female sex.

RESULTS

Among the recruited 219 BD subjects, 119 (54.3%) were females. Women had a lower scholarity (p = 0.015) and were less frequently employed (p = 0.001). As for psychopathological features, a higher MRS total score (p < 0.001) was detected among women, as well as higher BIS-11 total score (p = 0.040), and briefTEMPS-M score for anxious temperament (p = 0.006). Men showed higher prevalence of DSM-5 mixed features (p = 0.025), particularly during a depressive episode (p = 0.014). Women reported longer duration of untreated illness (DUI) (p < 0.001). There were no sex differences in the Alda Scale total score when considering the whole sample, but this was significantly higher among men (p = 0.030) when evaluating subjects treated with anticonvulsants. At the logistic regression, female sex was positively associated with longer DUI (p < 0.001; OR 1.106, 95% CI 1.050-1.165) and higher MRS total score (p < 0.001; OR 1.085, 95% CI 1.044-1.128) and negatively associated with employment (p = 0.003; OR 0.359, 95% CI 0.185-0.698) and DSM-5 mixed features (p = 0.006; OR 0.391, 95% CI 0.200-0.762).

CONCLUSIONS

The clinical presentation of BD may differ depending on sex. The severity of BD should not be neglected among women, who may also display worse treatment response to anticonvulsants.

How health care systems let our patients down: a systematic review into suicide deaths

PURPOSE

To synthesize the literature in relation to findings of system errors through reviews of suicide deaths in the public mental health system.

DATA SOURCES

A systematic narrative meta-synthesis using the PRISMA methodology was conducted.

STUDY SELECTION

All English language articles published between 2000 and 2017 that reported on system errors identified through reviews of suicide deaths were included. Articles that reported on patient factors, contact with General Practitioners or individual cases were excluded.

DATA EXTRACTION

Results were extracted and summarized. An overarching coding framework was developed inductively. This coding framework was reapplied to the full data set.

RESULTS OF DATA SYNTHESIS

Fourteen peer reviewed publications were identified. Nine focussed on suicide deaths that occurred in hospital or psychiatric inpatient units. Five studies focussed on suicide deaths while being treated in the community. Vulnerabilities were identified throughout the patient's journey (i.e. point of entry, transitioning between teams, and point of exit with the service) and centred on information gathering (i.e. inadequate and incomplete risk assessments or lack of family involvement) and information flow (i.e. transitions between different teams). Beyond enhancing policy, guidelines, documentation and regular training for frontline staff there were very limited suggestions as to how systems can make it easier for staff to support their patients.

CONCLUSIONS

There are currently limited studies that have investigated learnings and recommendations. Identifying critical vulnerabilities in systems and to be proactive about these could be one way to develop a highly reliable mental health care system.

Has Bipolar Disorder become a predominantly female gender related condition? Analysis of recently published large sample studies

Bipolar Disorders (BD) are disabling and severe psychiatric disorders, commonly perceived as equally affecting both men and women. The prevalence of BD in the general population has been growing over the last decade, however, few epidemiological studies are available regarding BD gender distribution, leaving unanswered the question whether the often reported increment of BD diagnosis could be gender specific. In fact, BD in female patients can often be misdiagnosed as MDD, leaving such women non correctly treated for longer times than their male counterparts. From this perspective, we searched literature for large sample (> 1000 subjects) studies published in the last decade (2010 onward) on BD patients. We included ten large sample studies that reported the gender distribution of their samples, and we therefore analysed them. Our results show a higher preponderance of female patients in every sample and sub-sample of BDI and BDII, supporting our hypothesis of an increase in BD diagnosis in females. BD in women presents with higher rates of rapid cycling, depressive polarity and suicide attempts, characteristics of non inferior severity compared to males; prompt recognition and adequate treatment of BD is therefore crucial to reduce risks and improve quality of life of affected women. In this regard, our results could lead the way for national or international epidemiological studies with the aim of more accurately assessing gender-specific prevalence of BD.

Higher prevalence of intentional self-harm in bipolar disorder with evening chronotype: A finding from the APPLE cohort study

BACKGROUND

Patients with bipolar disorder (BD) frequently self-harm, and this is strongly associated with subsequent suicide. This study investigated the association between chronotype and intentional self-harm in patients with BD.

METHODS

Two-hundred and five outpatients with BD participated in this cross-sectional study. Each participant's chronotype was evaluated using the Morningness-Eveningness Questionnaire, dividing the scores into three types: evening, 16-41 points; intermediate, 42-58 points; and morning, 59-86 points. Intentional self-harm over the past year were self-reported by questionnaire. Propensity score for evening chronotype was estimated from age, sex, socioeconomic factors, mood symptoms, total sleep time, age at the onset of BD, psychiatric inpatient history, family history of suicide, psychiatric comorbidity, and use of lithium.

RESULTS

Thirty-six (18%) of the 205 participants reported self-harm. A substantially higher proportion of the evening chronotype group self-harmed compared to the other groups (evening, 37%; intermediate, 13%; morning 10%). In multivariable analysis adjusted for propensity score, the odds ratio (OR) for self-harming significantly increased from morning to intermediate to evening chronotype (ORs: morning, 1.00; intermediate, 1.56; evening, 3.61; P for trend = 0.038).

LIMITATIONS

This study was a cross-sectional and small sample size.

CONCLUSIONS

Although a third factors, such as personality disorder or disrupted circadian rhythm, may have influenced, these findings suggest association between chronotype and intentional self-harm in BD patients.

Sex difference in the progression of manic symptoms during acute hospitalization: A prospective pilot study

OBJECTIVES

Acute mania is a serious medical condition that impacts men and women equally. Longtime presentation of manic symptoms is sex-dependent; however, little is known about acute symptoms of mania. The objective of this study is to track and compare acute manic symptoms for sex differences during inpatient hospitalization.

METHODS

All patients with bipolar mania admitted to a large university hospital between January and October 2017 were invited to participate in this longitudinal naturalistic follow-up study. Manic (YMRS), depressive (MADRS), and psychotic (PAS) symptoms were tracked daily from admission to discharge.

RESULTS

The total YMRS scores decreased significantly overtime (p < .0001) in both male (n = 34) and female (n = 23) patients (p = .7). However, male patients scored significantly higher in sexual interest (p = .01), disruptive and aggressive behavior (p = .01), and appearance (p < .001) while females had better insight into their illness (p = .01). Males and females received similar doses of lithium (p = .1), but males received significantly higher doses of valproic acid (VPA) in comparison with females (p = .003). However, plasma lithium and VPA concentrations at discharge were not significantly different between sexes.

CONCLUSION

Our results show sex differences in the progression of certain domains of manic symptoms in a cohort of 23 female and 34 male patients admitted to a large academic center in Turkey. Males, in this sample, exhibited more sexual interest, disruptive and aggressive behaviors, better grooming, and less insight compared to females. While these results are concordant with our preclinical findings and with anecdotal clinical observations, replication in larger samples is needed.

Qualitative investigation of relatives' and service users' experience of mental healthcare for suicidal behaviour in bipolar disorder

OBJECTIVE

People with bipolar disorder are known to be at high risk of engaging in suicidal behaviours, and those who die by suicide have often been in recent contact with mental health services. The objective of this study was to explore suicidal behaviour in bipolar disorder and how this is monitored and managed by mental health services.

AIMS

To identify themes within relatives' and service users' accounts of mental healthcare, related to management and prevention of suicidal behaviour in bipolar disorder.

DESIGN

Thematic analysis of 22 semistructured interviews.

PARTICIPANTS

Participants were aged 18 years or over, fluent in written and spoken English, and either had bipolar disorder with a history of suicidal behaviour, or were relatives of people with bipolar disorder who had died by suicide.

SETTING

England, UK.

PRIMARY OUTCOME

Themes identified from participants' accounts of mental healthcare for suicidal behaviours in bipolar disorder.

RESULTS

Two main themes were identified. 'Access to care' was characterised by a series or cycle of potential barriers to care (eg, gate-keepers, lack of an accurate diagnosis) which had the potential to increase risk of suicidal behaviour if failure to access care continued over time. 'Problems with communication' captured the importance of maintaining open routes of communication between all parties involved in care to ensure successful monitoring and management of suicidal behaviours in bipolar disorder.

CONCLUSIONS

Mental health services need to be accessible and respond rapidly to people with suicidal behaviour in bipolar disorder. Open communication and inclusion of relatives in care, where appropriate, could help closer monitoring of changes in symptoms that indicate increased risk.

Completed suicide in bipolar disorder patients: A cohort study after first hospitalization

BACKGROUND

Bipolar disorder (BD) is a mental health condition that has one of the greatest risk of completed suicide (CS). Hospitalization in affective disorders is associated with increased illness severity and suicide risk, so the study of suicide after the first hospitalization is of special interest.

METHOD

We studied a retrospective cohort consisting on all BD type I (BD-I) and II (BD-II) (according to DSM-IV criteria) admitted for the first time in their lives to the psychiatry unit of a general hospital between 1996 and 2016 from an area in Catalonia (Spain). All patients were also followed-up in a community center of mental health as outpatients until the end of 2017. Multiple variables were prospectively collected during the first hospital admission and were compared between patients who CS and those who did not.

RESULTS

14 of 313 (4.5%) bipolar patients included CS during the 11-year follow-up, and 93% used a violent method. In the univariate analysis we found that Bipolar II Disorder, treatment with antidepressants and/or with lamotrigine were associated with higher risk of CS, however, treatment with valproate and/or with antipsychotics were associated with lower risk of CS . After logistic regression multivariant analysis, only immediately previous violent suicide attempt and first-degree family history of CS remain significant risk factors of CS. A limitation is the relatively small sample from a local hospital and followed locally.

CONCLUSION

Followed during an average of 11 years after the first hospital admission, Bipolar patients completed suicide at a rate 58 times higher than the general population and almost always performed through a violent method. Violent attempted suicide before admission and first- degree family history of CS, are clear and potent predictors of completed suicide.

Association between completed suicide and bipolar disorder: A systematic review of the literature

BACKGROUND

Completed suicide is a major cause of death in bipolar disorder (BD) patients.

OBJECTIVE

The aim of this paper is to provide an overall review of the existing literature of completed suicide in BD patients, including clinical and genetic data DATA SOURCES: We performed a systematic review of English and non-English articles published on MEDLINE/PubMed, PsycInfo and Cochrane database (1970-2017). Additional studies were identified by contacting clinical experts, searching bibliographies, major textbooks and website of World Health Organization. Initially we did a broad search for the association of bipolar disorder and suicide and we were narrowing the search in terms included "bipolar disorder" and "completed suicide".

STUDY SELECTION

Inclusion criteria were articles about completed suicide in patients with BD. Articles exclusively focusing on suicide attempts and suicidal behaviour have been excluded. We used PRISMA (Preferred Reporting Items for Systematic reviews and Meta-Analyses) consensus for drafting this systematic review.

RESULTS

The initial search generated 2806 articles and a total of 61 meeting our inclusion criteria. We reviewed epidemiological data, genetic factors, risk factors and treatment of completed suicide in BD. Suicide rates in BD vary between studies but our analyses show that they are approximately 20-30-fold greater than in general population. The highest risk of successful suicide was observed in BD-II subjects. The heritability of completed suicide is about 40% and some genes related to major neurotransmitter systems have been associated with suicide. Lithium is the only treatment that has shown anti-suicide potential.

LIMITATIONS

The most important limitation of the present review is the limited existing literature on completed suicide in BD.

CONCLUSIONS

BD patients are at high risk for suicide. It is possible to identify some factors related to completed suicide, such as early onset, family history of suicide among first-degree relatives, previous attempted suicides, comorbidities and treatment. However it is necessary to promote research on this serious health problem.

Risk factors for suicide in bipolar disorder: a cohort study of 12 850 patients

OBJECTIVE

Bipolar disorder carries a high risk of suicide. Identification of risk factors is important. The aim of this study was to study risk factors for suicide in a large cohort of men and women with bipolar disorder.

METHOD

A prospective cohort study using clinical data from the Swedish National Quality Register for Bipolar Affective Disorder (BipoläR). The outcome variable was suicide captured in the Cause of Death Register between 2004 and 2014. Hazard ratios (HR) were calculated using Cox proportional hazards models.

RESULTS

Of 12 850 persons (4844 men and 8006 women) with bipolar disorder, 90 (55 men and 35 women) died by suicide during the follow-up period (between 1 and 10 years). Male sex (HR 2.56), living alone (HR 2.45), previous suicide attempts (HR 4.10), comorbid psychiatric disorder (HR 2.64), recent affective episodes (HR 2.39), criminal conviction (HR 4.43), psychiatric inpatient care (HR 2.79), and involuntary commitment (HR 3.50) were significant risk factors for suicide. Several of the statistically significant risk factors for suicide in bipolar disorder differed between men and women.

CONCLUSIONS

Risk factors for suicide in bipolar disorder include factors associated with suicide in general, but also diagnosis-specific factors.

Reducing relapse and suicide in bipolar disorder: practical clinical approaches to identifying risk, reducing harm and engaging service users in planning and delivery of care – the PARADES (Psychoeducation, Anxiety, Relapse, Advance Directive Evaluation and Suicidality) programme

Background

Bipolar disorder (BD) costs £5.2B annually, largely as a result of incomplete recovery after inadequate treatment.

Objectives

A programme of linked studies to reduce relapse and suicide in BD.

Design

There were five workstreams (WSs): a pragmatic randomised controlled trial (RCT) of group psychoeducation (PEd) versus group peer support (PS) in the maintenance of BD (WS1); development and feasibility RCTs of integrated psychological therapy for anxiety in bipolar disorder (AIBD) and integrated for problematic alcohol use in BD (WS2 and WS3); survey and qualitative investigations of suicide and self-harm in BD (WS4); and survey and qualitative investigation of service users’ (SUs) and psychiatrists’ experience of the Mental Capacity Act 2005 (MCA), with reference to advance planning (WS5).

Setting

Participants were from England; recruitment into RCTs was limited to certain sites [East Midlands and North West (WS1); North West (WS2 and WS3)].

Participants

Aged ≥ 18 years. In WS1–3, participants had their diagnosis of BD confirmed by the Structural Clinical Interview for theDiagnostic and Statistical Manual of Mental Disorders.

Interventions

In WS1, group PEd/PS; in WS3 and WS4, individual psychological therapy for comorbid anxiety and alcohol use, respectively.

Main outcome measures

In WS1, time to relapse of bipolar episode; in WS2 and WS3, feasibility and acceptability of interventions; in WS4, prevalence and determinants of suicide and self-harm; and in WS5, professional training and support of advance planning in MCA, and SU awareness and implementation.

Results

Group PEd and PS could be routinely delivered in the NHS. The estimated median time to first bipolar relapse was 67.1 [95% confidence interval (CI) 37.3 to 90.9] weeks in PEd, compared with 48.0 (95% CI 30.6 to 65.9) weeks in PS. The adjusted hazard ratio was 0.83 (95% CI 0.62 to 1.11; likelihood ratio testp = 0.217). The interaction between the number of previous bipolar episodes (1–7 and 8–19, relative to 20+) and treatment arm was significant (χ2 = 6.80, degrees of freedom = 2;p = 0.034): PEd with one to seven episodes showed the greatest delay in time to episode. A primary economic analysis indicates that PEd is not cost-effective compared with PS. A sensitivity analysis suggests potential cost-effectiveness if decision-makers accept a cost of £37,500 per quality-adjusted life-year. AIBD and motivational interviewing (MI) cognitive–behavioural therapy (CBT) trials were feasible and acceptable in achieving recruitment and retention targets (AIBD:n = 72, 72% retention to follow-up; MI-CBT:n = 44, 75% retention) and in-depth qualitative interviews. There were no significant differences in clinical outcomes for either trial overall. The factors associated with risk of suicide and self-harm (longer duration of illness, large number of periods of inpatient care, and problems establishing diagnosis) could inform improved clinical care and specific interventions. Qualitative interviews suggested that suicide risk had been underestimated, that care needs to be more collaborative and that people need fast access to good-quality care. Despite SUs supporting advance planning and psychiatrists being trained in MCA, the use of MCA planning provisions was low, with confusion over informal and legally binding plans.

Limitations

Inferences for routine clinical practice from WS1 were limited by the absence of a ‘treatment as usual’ group.

Conclusion

The programme has contributed significantly to understanding how to improve outcomes in BD. Group PEd is being implemented in the NHS influenced by SU support.

Future work

Future work is needed to evaluate optimal approaches to psychological treatment of comorbidity in BD. In addition, work in improved risk detection in relation to suicide and self-harm in clinical services and improved training in MCA are indicated.

Trial registration

Current Controlled Trials ISRCTN62761948, ISRCTN84288072 and ISRCTN14774583.

Funding

This project was funded by the National Institute for Health Research (NIHR) Programme Grants for Applied Research programme and will be published in full inProgramme Grants for Applied Research; Vol. 6, No. 6. See the NIHR Journals Library website for further project information.

Blink reflex under external emotional-stimuli in bipolar I and II disorders

Bipolar disorder types I (BD I) and II (BD II) might present different cortico-brainstem circuit dysfunctions under external emotions, which might be reflected by the blink reflex. We therefore invited 32 BD I and 23 BD II patients, and 46 healthy volunteers to answer the Mood Disorder Questionnaire, the Hypomania Checklist-32, and the Plutchik - van Praag Depression inventory, and to undergo the blink reflex test under external emotions (emotional pictures plus sounds) of Disgust, Erotica, Fear, Happiness, and Sadness. Compared to healthy controls, BD I showed prolonged R2/R2' latencies under most emotions, and their PVP scores were negatively correlated with the areas under curve (AUCs) of R2 and R2' under Erotica; and BD II showed reduced R2/R2' AUCs under all emotions. Moreover, R2' AUCs under Disgust, Fear, and Happiness were significantly reduced in BD II than those in BD I. Our results have shown that, irrespective of patients' on-going affective states, the R2/R2' components were delayed in BD I but suppressed in BD II under most external emotions. Our study provides some hints to distinguish the two types of bipolar disorder, referring to the cortico-brainstem circuit dysfunctions under external emotions.

Self-poisoning suicide deaths in people with bipolar disorder: characterizing a subgroup and identifying treatment patterns

OBJECTIVE

To characterize self-poisoning suicide deaths in BD compared to other suicide decedents.

METHODS

Extracted coroner data from all suicide deaths (n = 3319) in Toronto, Canada from 1998 to 2012. Analyses of demographics, clinical history, recent stressors, and suicide details were conducted in 5 subgroups of suicide decedents: BD self-poisoning, BD other methods, non-BD self-poisoning, non-BD other methods, and unipolar depression self-poisoning. Toxicology results for lethal and present substances were also compared between BD and non-BD self-poisoning subgroups as well as between BD and unipolar depression self-poisoning subgroups.

RESULTS

Among BD suicide decedents, self-poisoning was significantly associated with female sex, past suicide attempts, and comorbid substance abuse. In both the BD and non-BD self-poisoning groups, opioids were the most common class of lethal medication. For both groups, benzodiazepines and antidepressants were the most common medications present at time of death, and in 23% of the BD group, an antidepressant was present without a mood stabilizer or antipsychotic. Only 31% of the BD group had any mood stabilizer present, with carbamazepine being most common. No antidepressant, mood stabilizer, or antipsychotic was present in 15.5% of the BD group. Relative to unipolar depression self-poisoning group, the BD self-poisoning group evidenced higher proportion of previous suicide attempt(s) and psychiatry/ER visits in the previous week.

CONCLUSION

People with BD who die by suicide via self-poisoning comprise a distinct but understudied group. The predominant absence of guideline-concordant pharmacologic care comprises a crucial target for future policy and knowledge translation efforts.

Pharmacological Treatment of Bipolar Disorder with Comorbid Alcohol Use Disorder

Bipolar disorder (BD) spectrum and alcohol use disorders (AUDs) commonly occur together. Comorbidity between the two conditions predisposes patients to elevated risks of adverse outcomes, including hospitalization and suicide, compared with either condition alone. Despite the consistent relationship observed between BD and AUD, the underlying cause remains incompletely characterized. Few trials conducted have been able to identify promising interventions for patients with these disease states. The antipsychotic quetiapine has been evaluated most commonly as a therapeutic agent for patients with BD and AUD followed by naltrexone and acamprosate. Randomized controlled trials of quetiapine have consistently reported a lack of efficacy for the treatment of patients with BD and AUD. Trials of acamprosate have also been negative but small in size. Results of the sole randomized controlled trial of naltrexone have found large treatment effect sizes, but no statistically significant difference between treatment groups. Other agents including the antipsychotic aripiprazole, mood stabilizing agents including lamotrigine, lithium, and divalproex, and the antiepileptic agent topiramate have also been evaluated for the treatment of BD and AUD with mixed findings. The lone statistically significant treatment effect was observed in a randomized, placebo-controlled trial of divalproex added on to lithium which demonstrated a reduction in alcohol use. This review summarizes the available clinical evidence and current guideline recommendations for the treatment of comorbid BD and AUD, and provides discussion and recommendations based on the current literature.

Inhibitory brainstem reflexes under external emotional-stimuli in bipolar I and II disorders

BACKGROUND

Bipolar disorder types I (BD I) and II (BD II) might present different dysfunctions of the cortex and brainstem, as reflected by the second exteroceptive suppression period of temporalis muscle activity (ES2) under different stimuli of external emotions.

METHODS

This study included 30 BD I and 20 BD II patients, and 40 healthy volunteers. All participants were invited to answer the Mood Disorder Questionnaire, the Hypomania Checklist-32, and the Plutchik-van Praag Depression inventory, as well as to undergo the ES2 test under external emotional-stimuli (emotional pictures plus sounds) of Disgust, Erotica, Fear, Happiness, and Sadness.

RESULTS

The scale scores were elevated in both patient groups, but were not correlated with ES2 parameters. Compared to healthy controls, BD I showed prolonged ES2 latency under Erotica, and their perceived happiness and sadness intensities were negatively correlated with the respective ES2 durations, while BD II showed prolonged ES2 latencies under Disgust and Happiness, and shortened ES2 durations under Disgust, Happiness and Sadness. Moreover, ES2 duration under Sadness was significantly shorter in BD II than that in BD I.

CONCLUSIONS

The cortico-brainstem inhibitory dysfunctions in BD I and BD II was different, and this difference was independent of the patient's ongoing emotions. Our study thus provides some hints to distinguish the two types of bipolar disorders.

A balanced translocation disrupting BCL2L10 and PNLDC1 segregates with affective psychosis

Affective psychoses are a group of severe psychiatric disorders, including schizoaffective disorder and bipolar I disorder, together affecting ∼1% of the population. Despite their high heritability, the molecular genetics and neurobiology of affective psychosis remain largely elusive. Here, we describe the identification of a structural genetic variant segregating with affective psychosis in a family with multiple members suffering from bipolar I disorder or schizoaffective disorder, bipolar type. A balanced translocation involving chromosomes 6 and 15 was detected by karyotyping and fluorescence in-situ hybridization (FISH). Using whole-genome sequencing, we rapidly delineated the translocation breakpoints as corresponding intragenic events disrupting BCL2L10 and PNLDC1. These data warrant further consideration for BCL2L10 and PNLDC1 as novel candidates for affective psychosis. © 2016 The Authors. American Journal of Medical Genetics Part B: Neuropsychiatric Genetics Published by Wiley Periodicals, Inc.

Evidence-based guidelines for treating bipolar disorder: Revised third edition recommendations from the British Association for Psychopharmacology

The British Association for Psychopharmacology guidelines specify the scope and targets of treatment for bipolar disorder. The third version is based explicitly on the available evidence and presented, like previous Clinical Practice Guidelines, as recommendations to aid clinical decision making for practitioners: it may also serve as a source of information for patients and carers, and assist audit. The recommendations are presented together with a more detailed review of the corresponding evidence. A consensus meeting, involving experts in bipolar disorder and its treatment, reviewed key areas and considered the strength of evidence and clinical implications. The guidelines were drawn up after extensive feedback from these participants. The best evidence from randomized controlled trials and, where available, observational studies employing quasi-experimental designs was used to evaluate treatment options. The strength of recommendations has been described using the GRADE approach. The guidelines cover the diagnosis of bipolar disorder, clinical management, and strategies for the use of medicines in short-term treatment of episodes, relapse prevention and stopping treatment. The use of medication is integrated with a coherent approach to psychoeducation and behaviour change.

Harnessing the potential of community-based participatory research approaches in bipolar disorder

Background

Despite the rapid growth in the sophistication of research on bipolar disorder (BD), the field faces challenges in improving quality of life (QoL) and symptom outcomes, adapting treatments for marginalized communities, and disseminating research insights into real-world practice. Community-based participatory research (CBPR)—research that is conducted as a partnership between researchers and community members—has helped address similar gaps in other health conditions. This paper aims to improve awareness of the potential benefits of CBPR in BD research.

Methods

This paper is a product of the International Society for Bipolar Disorders (ISBD) Taskforce on Community Engagement which includes academic researchers, healthcare providers, people with lived experience of BD, and stakeholders from BD community agencies. Illustrative examples of CBPR in action are provided from two established centres that specialize in community engagement in BD research: the Collaborative RESearch Team to study psychosocial issues in BD (CREST.BD) in Canada, and the Spectrum Centre for Mental Health Research in the United Kingdom.

Results and discussion

We describe the philosophy of CBPR and then introduce four core research areas the BD community has prioritized for research: new treatment approaches, more comprehensive outcome assessments, tackling stigma, and enhanced understanding of positive outcomes. We then describe ways in which CBPR is ideal for advancing each of these research areas and provide specific examples of ways that CBPR has already been successfully applied in these areas. We end by noting potential challenges and mitigation strategies in the application of CBPR in BD research.

Conclusions

We believe that CBPR approaches have significant potential value for the BD research community. The observations and concerns of people with BD, their family members, and supports clearly represent a rich source of information. CBPR approaches provide a collaborative, equitable, empowering orientation to research that builds on the diversity of strengths amongst community stakeholders. Despite the potential merits of this approach, CBPR is as yet not widely used in the BD research field, representing a missed opportunity.

Clinical features, comorbidity, and cognitive impairment in elderly bipolar patients

INTRODUCTION

Data specific to late-life bipolar disorder (BD) are limited. Current research is sparse and present guidelines are not adapted to this group of patients.

OBJECTIVES

We present a literature review on clinical characteristics, comorbidities, and cognitive impairment in patients with late-life BD. This review discusses common comorbidities that affect BD elders and how aging might affect cognition and treatment.

METHODS

Eligible studies were identified in MedLine by the Medical Subject Headings terms "bipolar disorder" and "aged". We only included original research reports published in English between 2012 and 2015.

RESULTS

From 414 articles extracted, 16 studies were included in the review. Cardiovascular and respiratory conditions, type II diabetes, and endocrinological abnormalities were observed as highly prevalent. BD is associated with a high suicide risk. Bipolar elderly had an increased risk of dementia and performed worse on cognitive screening tests compared to age-matched controls across different levels of cognition. Despite high rates of medical comorbidity among bipolar elderly, a systematic under-recognition and undertreatment of cardiovascular disease have been suggested.

CONCLUSION

There was a high burden of physical comorbidities and cognitive impairment in late-life BD. Bipolar elderly might be under-recorded and undertreated in primary medical care, indicating that this group needs an adapted clinical assessment and specific clinical guidelines need to be established.

A review of factors associated with greater likelihood of suicide attempts and suicide deaths in bipolar disorder: Part II of a report of the International Society for Bipolar Disorders Task Force on Suicide in Bipolar Disorder

OBJECTIVES

Many factors influence the likelihood of suicide attempts or deaths in persons with bipolar disorder. One key aim of the International Society for Bipolar Disorders Task Force on Suicide was to summarize the available literature on the presence and magnitude of effect of these factors.

METHODS

A systematic review of studies published from 1 January 1980 to 30 May 2014 identified using keywords 'bipolar disorder' and 'suicide attempts or suicide'. This specific paper examined all reports on factors putatively associated with suicide attempts or suicide deaths in bipolar disorder samples. Factors were subcategorized into: (1) sociodemographics, (2) clinical characteristics of bipolar disorder, (3) comorbidities, and (4) other clinical variables.

RESULTS

We identified 141 studies that examined how 20 specific factors influenced the likelihood of suicide attempts or deaths. While the level of evidence and degree of confluence varied across factors, there was at least one study that found an effect for each of the following factors: sex, age, race, marital status, religious affiliation, age of illness onset, duration of illness, bipolar disorder subtype, polarity of first episode, polarity of current/recent episode, predominant polarity, mood episode characteristics, psychosis, psychiatric comorbidity, personality characteristics, sexual dysfunction, first-degree family history of suicide or mood disorders, past suicide attempts, early life trauma, and psychosocial precipitants.

CONCLUSION

There is a wealth of data on factors that influence the likelihood of suicide attempts and suicide deaths in people with bipolar disorder. Given the heterogeneity of study samples and designs, further research is needed to replicate and determine the magnitude of effect of most of these factors. This approach can ultimately lead to enhanced risk stratification for patients with bipolar disorder.

Epidemiology, neurobiology and pharmacological interventions related to suicide deaths and suicide attempts in bipolar disorder: Part I of a report of the International Society for Bipolar Disorders Task Force on Suicide in Bipolar Disorder

OBJECTIVES

Bipolar disorder is associated with elevated risk of suicide attempts and deaths. Key aims of the International Society for Bipolar Disorders Task Force on Suicide included examining the extant literature on epidemiology, neurobiology and pharmacotherapy related to suicide attempts and deaths in bipolar disorder.

METHODS

Systematic review of studies from 1 January 1980 to 30 May 2014 examining suicide attempts or deaths in bipolar disorder, with a specific focus on the incidence and characterization of suicide attempts and deaths, genetic and non-genetic biological studies and pharmacotherapy studies specific to bipolar disorder. We conducted pooled, weighted analyses of suicide rates.

RESULTS

The pooled suicide rate in bipolar disorder is 164 per 100,000 person-years (95% confidence interval = [5, 324]). Sex-specific data on suicide rates identified a 1.7:1 ratio in men compared to women. People with bipolar disorder account for 3.4-14% of all suicide deaths, with self-poisoning and hanging being the most common methods. Epidemiological studies report that 23-26% of people with bipolar disorder attempt suicide, with higher rates in clinical samples. There are numerous genetic associations with suicide attempts and deaths in bipolar disorder, but few replication studies. Data on treatment with lithium or anticonvulsants are strongly suggestive for prevention of suicide attempts and deaths, but additional data are required before relative anti-suicide effects can be confirmed. There were limited data on potential anti-suicide effects of treatment with antipsychotics or antidepressants.

CONCLUSION

This analysis identified a lower estimated suicide rate in bipolar disorder than what was previously published. Understanding the overall risk of suicide deaths and attempts, and the most common methods, are important building blocks to greater awareness and improved interventions for suicide prevention in bipolar disorder. Replication of genetic findings and stronger prospective data on treatment options are required before more decisive conclusions can be made regarding the neurobiology and specific treatment of suicide risk in bipolar disorder.

Pharmacotherapy of bipolar disorder with quetiapine: a recent literature review and an update

Bipolar disorder is a chronic, recurrent condition with the usual onset during adolescence or early adulthood. In the Diagnostic and Statistical Manual of Mental Disorders 5th edition, it is conceptualized as a spectrum disorder usually associated with such comorbidities as anxiety disorders and substance use disorders. It is a relatively prevalent condition often complicated by mixed episodes, rapid cycling, subsyndromal symptoms, and treatment refractoriness. In spite of carrying substantial morbidity and mortality, effective treatments are few and far between and conventional mood stabilizers are often unsuccessful in controlling the various manifestations of the disorder. In this scenario, second generation antipsychotics are emerging as treatments with valid efficacy in all phases of bipolar disorder. Quetiapine is a versatile atypical antipsychotic which was first approved for the treatment of schizophrenia, but latter on the basis of controlled studies earned United States Food and Drug Administration’s approval for acute as well as maintenance treatment of this difficult to treat condition. In this review, recently published studies in the last 10 years were examined to update the knowledge about the efficacy and safety of quetiapine in the treatment of bipolar disorder. The medication’s clinical pharmacology was first considered followed by a literature review summarizing its uses in bipolar disorder. The conclusion was that quetiapine was efficacious in manic, mixed and depressive episodes and as a maintenance agent with a good tolerability profile.

Self-harm in bipolar disorder: findings from a prospective clinical database

BACKGROUND

People with bipolar disorder may be at increased risk of suicidal behaviour but there are few prospective studies of self-harm in this group. Our aim was to describe the characteristics and outcome (in terms of repetition) for individuals with bipolar disorder who presented to hospital following self-harm.

METHOD

A nested case-control study was carried out using a large prospective self-harm database (1997-2010) in Manchester, UK. Characteristics of bipolar cases and non-bipolar controls were compared using conditional logistic regression, and outcomes were assessed via survival analyses.

RESULTS

Bipolar cases (n=103) were more likely to repeat self-harm than controls (n=515): proportion with at least one repeat episode 58% vs. 25%, HR 3.08 (95% CI; 2.2-4.18). Previous self-harm, unemployment, contact with psychiatric services and sleep disturbance were all more common in cases than controls. Even after adjustment for known risk factors, the risk of repetition remained higher in the bipolar group (adjusted HR 1.68; 95% CI; 1.10-2.56).

LIMITATIONS

The study covers cases from hospital sites in Manchester, UK, and therefore only includes self-harm that was serious enough to present at hospital emergency departments.

CONCLUSION

People with bipolar disorder who self-harm have a higher risk of repetition than people who self-harm more generally. Adjusting for some known risk factors moderated, but did not abolish, this finding. Other factors, such as impulsivity, may also be important.

Risk factors for suicide in bipolar disorder: a systematic review

BACKGROUND

Bipolar disorder confers the highest risk of suicide among major psychological disorders. The risk factors associated with bipolar disorder and suicide exist and are relevant to clinicians and researchers.

OBJECTIVE

The aim of the present study was to conduct a systematic review of articles regarding the suicide risk factors in bipolar disorder.

METHODS

A systematic review of articles on suicide risk factors in bipolar disorder, published from January 1, 2010 to April 05, 2014, on SCOPUS and PUBMED databases was carried out. Search terms were "Suicide" (medical subject headings [MeSH]), "Risk factors" (MeSH), and "Bipolar" (keyword). Of the 220 retrieved studies, 42 met the eligibility criteria.

RESULTS

Bipolar disorder is associated with an increased rate death by suicide which contributes to overall mortality rates. Studies covered a wide range of aspects regarding suicide risk factors in bipolar disorder, such as risk factors associated to Sociodemographic conditions, Biological characteristics, Drugs Relationships, Psychological Factors, Genetic Compound, Religious and Spirituals conditions. Recent scientific literature regarding the suicide risk factors in bipolar disorder converge to, directly or indirectly, highlight the negative impacts of risk factors to the affected population quality of life.

CONCLUSION

This review demonstrated that Bipolar disorders commonly leads to other psychiatric disorders and co-morbidities involving risk of suicide. Thus the risk factors are relevant to have a better diagnosis and prognosis of BD cases involving risk of suicide.

CRY1 Variations Impacts on the Depressive Relapse Rate in a Sample of Bipolar Patients

OBJECTIVE

A relevant part of the social and personal burden caused by Bipolar Disorder (BD) is related to depressive phases. Authors investigated the genetic impact of a set of variations located in CRY1, a gene involved in the control of the circadian rhythms, towards depressive episodes in a sample of bipolar patients from the STEP-BD sample. As a secondary analysis, CYR1 variations were analyzed as predictors of sleep disruption.

METHODS

654 bipolar patients were included in the analysis. Data were available genome-wide. The part of the genome coding for the CRY1 was imputed and pruned according to standards in the field. 7 SNPs were available for the analysis. A correction for multitesting was applied and we had sufficient power (0.80) to detect a small-medium effect size (0.22) between two allelic frequencies each one represented by at least 300 subjects.

RESULTS

Intronic rs10861688 was associated with the number of depressive events corrected for the times patients were assessed during the period of observation. In particular, AA subjects (n=21) had 4.46±3.15 events, AG (n=141) had 3.08±3.17 and GG (n=342) 2.65±2.97 (p=0.0048, beta=-0.22). No other significant associations were reported.

CONCLUSION

We bring further evidence that genes involved in the regulation of circadian rhythms may be relevant to depressive bipolar phases. Independent confirmation analyses are mandatory.

Suicide in bipolar disorder: characteristics and subgroups

OBJECTIVES

The development of more sophisticated models for understanding suicide among people with bipolar disorder (BD) requires diagnosis-specific data. The present study aimed to elucidate differences between people who die by suicide with and without BD, and to identify subgroups within those with BD.

METHODS

Data on all suicide deaths in the city of Toronto from 1998 to 2010 were extracted from the Office of the Chief Coroner of Ontario, including demographics, clinical variables, recent stressors, and details of the suicide. Comparisons of person- and suicide-specific variables between suicide deaths among those with BD (n = 170) and those without (n = 2,716) were conducted, and a cluster analysis was performed among the BD suicide group only.

RESULTS

Those in the BD suicide group were more likely than those in the non-BD suicide group to be female [odds ratio (OR) = 1.75, 95% confidence interval (CI): 1.27-2.42; p = 0.001], to have made a past suicide attempt (OR = 2.01, 95% CI: 1.45-2.80; p < 0.0001), and to have had recent contact with psychiatric or emergency services (OR = 1.59, 95% CI: 1.00-2.52; p = 0.049). Five clusters were identified within the BD group, with differences between clusters in age; sex; marital status; living circumstances; past suicide attempts; substance abuse; interpersonal, employment/financial, and legal/police stressors; and rates of death by fall/jump or self-poisoning.

CONCLUSIONS

The present findings identified differences between BD and non-BD suicide groups, providing support to the utilization of an illness-specific approach to better understanding suicide in BD. Subgroups of BD suicide deaths, if replicated, should also be incorporated into the design and analysis of future studies of suicide in BD.

The role of the serotonergic system in suicidal behavior

Serotonin is a widely investigated neurotransmitter in several psychopathologies, including suicidal behavior (SB); however, its role extends to several physiological functions involving the nervous system, as well as the gastrointestinal and cardiovascular systems. This review summarizes recent research into ten serotonergic genes related to SB. These genes - TPH1, TPH2, SLC6A4, SLC18A2, HTR1A, HTR1B, HTR2A, DDC, MAOA, and MAOB - encode proteins that are vital to serotonergic function: tryptophan hydroxylase; the serotonin transporter 5-HTT; the vesicular transporter VMAT2; the HTR1A, HTR1B, and HTR2A receptors; the L-amino acid decarboxylase; and the monoamine oxidases. This review employed a systematic search strategy and a narrative research methodology to disseminate the current literature investigating the link between SB and serotonin.