Neurocognitive predictors of long-term clinical course in bipolar disorder

Clinical, sociodemographic and environmental predicting factors for relapse in bipolar disorder: A systematic review

INTRODUCTION

Bipolar disorder (BD) is a chronic and recurrent illness characterized by manic, mixed or depressive episodes, alternated with periods of euthymia. Several prognostic factors are associated with higher rates of relapse, which is crucial for the identification of high-risk individuals. This study aimed at systematically reviewing the existing literature regarding the impact of sociodemographic, clinical and environmental factors, in clinical relapses, recurrences and hospitalizations due to mood episodes in BD.

METHODS

A systematic search of electronic databases (PubMed, Cochrane library and Web of Science) was conducted to integrate current evidence about the impact of specific risk factors in these outcomes.

RESULTS

Fifty-eight articles met the inclusion criteria. Studies were grouped by the type of factors assessed. Family and personal psychiatric history, more severe previous episodes, earlier age of onset, and history of rapid cycling are associated with clinical relapses, along with lower global functioning and cognitive impairments. Unemployment, low educational status, poorer social adjustment and life events are also associated with higher frequency of episodes, and cannabis with a higher likelihood for rehospitalization.

LIMITATIONS

Small sample sizes, absence of randomized clinical trials, diverse follow-up periods, lack of control for some confounding factors, heterogeneous study designs and diverse clinical outcomes.

CONCLUSIONS

Although current evidence remains controversial, several factors have been associated with an impaired prognosis, which might allow clinicians to identify patients at higher risk for adverse clinical outcomes and find modifiable factors. Further research is needed to elucidate the impact of each risk factor in the mentioned outcomes.

Improved estimation of the risk of manic relapse by combining clinical and brain scan data

INTRODUCTION

Estimating the risk of manic relapse could help the psychiatrist individually adjust the treatment to the risk. Some authors have attempted to estimate this risk from baseline clinical data. Still, no studies have assessed whether the estimation could improve by adding structural magnetic resonance imaging (MRI) data. We aimed to evaluate it.

MATERIAL AND METHODS

We followed a cohort of 78 patients with a manic episode without mixed symptoms (bipolar type I or schizoaffective disorder) at 2-4-6-9-12-15-18 months and up to 10 years. Within a cross-validation scheme, we created and evaluated a Cox lasso model to estimate the risk of manic relapse using both clinical and MRI data.

RESULTS

The model successfully estimated the risk of manic relapse (Cox regression of the time to relapse as a function of the estimated risk: hazard ratio (HR)=2.35, p=0.027; area under the curve (AUC)=0.65, expected calibration error (ECE)<0.2). The most relevant variables included in the model were the diagnosis of schizoaffective disorder, poor impulse control, unusual thought content, and cerebellum volume decrease. The estimations were poorer when we used clinical or MRI data separately.

CONCLUSION

Combining clinical and MRI data may improve the risk of manic relapse estimation after a manic episode. We provide a website that estimates the risk according to the model to facilitate replication by independent groups before translation to clinical settings.

Factors associated with hospitalization times and length of stay in patients with bipolar disorder

Aim

Appraise the clinical features and influencing factors of the hospitalization times and length of stay in bipolar disorder (BD) patients.

Methods

This is a multicenter, observational, cohort study of patients diagnosed of type I or type II bipolar disorder. Five hundred twenty outpatients in seven hospitals from six cities in China were recruited from February 2013 to June 2014 and followed up using a continuous sampling pattern. The research included a retrospective period of 12 months and the prospective period of 9 months. The demographic and clinical features of the patients were collected. The influencing factors that could affect the length of stay (number of days spent in the hospital in the prospective period) were analyzed by poisson's regression and the hospitalization times (times of hospitalization in the prospective and retrospective period) was analyzed by general linear model. The selected variables included gender, age, years of education, occupational status, residence status, family history of mental disease, comorbid substance abuse, comorbid anxiety disorder, times of suicide (total suicide times that occurred in the retrospective and prospective period), polarity of the first mood episode, and BD type(I/II).

Results

Poisson's regression analysis showed that suicide times [Incidence Rate Ratio (IRR) = 1.20, p < 0.001], use of antipsychotic (IRR = 0.62, p = 0.011), and use of antidepressant (IRR = 0.56, p < 0.001) were correlated to more hospitalization times. Linear regression analysis showed that BD type II (β = 0.28, p = 0.005) and unemployment (β = 0.16, p = 0.039) which might mean longer duration of depression and poor function were correlated to longer length of stay. However, patients who experienced more suicide times (β = -0.21, p = 0.007) tended to have a shorter length of stay.

Conclusion

Overall, better management of the depressive episode and functional rehabilitation may help to reduce the length of stay. BD patients with more hospitalization times were characterized by higher risk of suicide and complex polypharmacy. Patients at high risk of suicide tended to have inadequate therapy and poor compliance, which should be assessed and treated adequately during hospitalization.

Clinical trial registration

www.ClinicalTrials.gov, Identifier: NCT01770704.

Associations between emotional and non-emotional cognition and subsequent mood episodes in recently diagnosed patients with bipolar disorder: A 16-month follow-up study

BACKGROUND

Bipolar disorder (BD) is associated with impairments in both emotional and non-emotional cognition. Recently, cognitive impairments have attracted increasing research interest as markers of prognosis and possible treatment targets in patients with BD. However, there is a paucity of studies investigating cognitive predictors of prognosis in BD.

METHODS

We assessed 148 recently diagnosed, symptomatically stable patients with BD with a battery of emotional and non-emotional cognitive tests and followed them up over 16 months as part of an ongoing cohort study. Multiple linear regression analyses were conducted to examine the associations between cognitive performance at baseline and the recurrence and duration of (hypo)manic and depressive episodes, respectively, with adjustment for age, sex, subsyndromal symptoms and time between assessments.

RESULTS

Poorer recognition of negative facial expressions and more negative emotions in neutral daily life scenarios were associated with greater frequency (ps ≤ .04) and longer duration (ps ≤ .03) of subsequent (hypo)manic episodes over the 16-month follow-up period. In addition, poorer global cognition, attention and psychomotor speed, and verbal fluency were associated with more (hypo)manic episodes (ps ≤ .04). Finally, more difficulty down-regulating emotion in negative social scenarios was associated with depressive relapse (p = .007). It was a limitation that patients had a delayed diagnosis of seven years from their first mood episode despite being recently diagnosed.

CONCLUSION

Trait-related cognitive impairments influence the early course in recently diagnosed patients with BD, particularly (hypo)manic relapse. Early prophylactic strategies targeting cognitive impairments may increase resilience and the course of illness in recently diagnosed patients with BD.

Randomised controlled cognition trials in remitted patients with mood disorders published between 2015 and 2021: A systematic review by the International Society for Bipolar Disorders Targeting Cognition Task Force

BACKGROUND

Cognitive impairments are an emerging treatment target in mood disorders, but currently there are no evidence-based pro-cognitive treatments indicated for patients in remission. With this systematic review of randomised controlled trials (RCTs), the International Society for Bipolar Disorders (ISBD) Targeting Cognition Task force provides an update of the most promising treatments and methodological recommendations.

METHODS

The review included RCTs of candidate pro-cognitive interventions in fully or partially remitted patients with major depressive disorder or bipolar disorder. We followed the procedures of the Preferred Reporting Items for Systematic reviews and Meta-Analysis (PRISMA) 2020 statement. Searches were conducted on PubMed/MEDLINE, PsycInfo, EMBASE and Cochrane Library from January 2015, when two prior systematic reviews were conducted, until February 2021. Two independent authors reviewed the studies with the Revised Cochrane Collaboration's Risk of Bias tool for Randomised trials.

RESULTS

We identified 16 RCTs (N = 859) investigating cognitive remediation (CR; k = 6; N = 311), direct current or repetitive magnetic stimulation (k = 3; N = 127), or pharmacological interventions (k = 7; N = 421). CR showed most consistent cognitive benefits, with two trials showing improvements on primary outcomes. Neuromodulatory interventions revealed no clear efficacy. Among pharmacological interventions, modafinil and lurasidone showed early positive results. Sources of bias included small samples, lack of pre-screening for objective cognitive impairment, no primary outcome and no information on allocation sequence masking.

CONCLUSIONS

Evidence for pro-cognitive treatments in mood disorders is emerging. Recommendations are to increase sample sizes, pre-screen for impairment in targeted domain(s), select one primary outcome, aid transfer to real-world functioning, investigate multimodal interventions and include neuroimaging.

Associations between cognition and subsequent mood episodes in patients with bipolar disorder and their unaffected relatives: A systematic review

BACKGROUND

Bipolar disorder (BD) is highly recurrent and prevention of relapse and illness onset is an urgent treatment priority. This systematic review examined whether cognitive assessments can aid prediction of recurrence in patients with BD and/or illness onset in individuals at familial risk.

METHODS

The review included longitudinal studies of patients with BD or individuals at familial risk of mood disorder that examined the association between cognitive functions and subsequent relapse or illness onset, respectively. We followed the procedures of the Preferred Reporting Items for Systematic reviews and Meta-Analysis (PRISMA) 2020 statement. Searches were conducted on PubMed/MEDLINE, EMBASE and PsychInfo databases from inception up until May 10th 2021.

RESULTS

We identified 19 eligible studies; 12 studies investigated cognitive predictors of recurrence in BD (N = 36-76) and seven investigated cognitive predictors of illness onset in at-risk individuals (N = 84-234). In BD, general cognitive impairment, poorer verbal memory and executive function and positive bias were associated with subsequent (hypo)manic relapse -but with not depressive relapse or mood episodes in general. In first-degree relatives, impairments in attention, verbal memory and executive functions and positive bias were associated with subsequent illness onset.

LIMITATIONS

The findings should be considered preliminary given the small-to-moderate sample sizes and scarcity of studies.

CONCLUSIONS

Subject to replication, the associations between cognitive impairment and (hypo)mania relapse and illness onset may provide a platform for personalised treatment and prophylactic strategies.

Clinical predictors of recurrences in bipolar disorders type 1 and 2: A FACE-BD longitudinal study

OBJECTIVE

To examine which characteristics predict the time to a first mood recurrence at three years in Bipolar Disorder type I (BD-I) and type II (BD-II).

METHODS

Individuals with BD were followed up to 3 years. Turbull's extension of the Kaplan-Meier analysis for interval-censored data was used to estimate the cumulative probability of recurrence over time. Separate models were performed according to BD subtype to determine which baseline factors were predictive of recurrences and were adjusted for age, gender and educational level.

RESULTS

We included 630 individuals with BD-I and 505 with BD-II. The first recurrence of any polarity occurred earlier in BD-II (p = 0.03). The first depressive recurrence occurred earlier in BD-II (p < 0.0001), whereas the first (hypo)manic recurrence occurred earlier in BD-I (p = 0.0003). In BD-I, the clinical variables that were associated to the time to a first mood recurrence were depressive symptoms, lifetime rapid cycling, global activation and the number of psychotropic medications at baseline. In BD-II, the time to a first recurrence was associated with a younger age at onset of BD and a higher number of lifetime mood episodes. The Areas Under the Curve for both models were moderate.

CONCLUSION

Predictors of recurrences showed few specificities to BD-I or BD-II. The ability to predict recurrences in BD based on socio-demographic and clinical variables remained too moderate for a transfer in daily practice. This study highlights the need for further studies that would include other types of predictors, such as molecular, cognitive or neuro-imaging ones, to achieve an accurate level of prediction of recurrences in BD.