Family members of people with mental illness (MI) may experience a host of psychological adversities such as increased stress, burden, and reduced wellbeing. However, relatively little is known about siblings. This study aimed to characterise the experience of distress (viz. depressive and anxiety symptoms), burden, and wellbeing in siblings of people with MI.

Studies reporting on quantitative measures of depression, anxiety, burden, or wellbeing in siblings; and/or qualitative findings on siblings’ experience were eligible. The literature search was conducted up until 20th October 2022.

Sixty-two studies comprising data from 3744 siblings were included. The pooled mean percentage of depressive symptoms fell in the mild range at 15.71 (k = 28, N = 2187, 95% CI 12.99–18.43) and anxiety symptoms fell in the minimal range at 22.45 (k = 16, N = 1122, 95% CI 17.09–27.80). Moderator analyses indicate that siblings of people with a schizophrenia spectrum disorder experience greater depressive symptoms than siblings of people with other types of MI (β = −16.38, p < 0.001). Qualitative findings suggest that individuals may be particularly vulnerable during their siblings’ illness onset and times of relapse. Limited communication, confusion about MI, and the need to compensate may contribute to siblings’ distress and/or burden. Siblings’ experience of wellbeing and caregiving were closely related.

This review highlights the complex psychological experience of siblings and the need for greater research and clinical support for this important yet often overlooked cohort.

The phenomenology of unipolar and bipolar disorders differ in a number of ways, such as the presence of mixed states and atypical features. Conventional depression rating instruments are designed to capture the characteristics of unipolar depression and have limitations in capturing the breadth of bipolar disorder.

The Bipolar Depression Rating Scale (BDRS) was administered together with the Montgomery Asberg Rating Scale (MADRS) and Young Mania Rating Scale (YMRS) in a double-blind randomised placebo-controlled clinical trial of N-acetyl cysteine for bipolar disorder (N = 75).

A factor analysis showed a two-factor solution: depression and mixed symptom clusters. The BDRS has strong internal consistency (Cronbach's alpha = 0.917), the depression cluster showed robust correlation with the MADRS (r = 0.865) and the mixed subscale correlated with the YMRS (r = 0.750).

The BDRS has good internal validity and inter-rater reliability and is sensitive to change in the context of a clinical trial.

Recent studies have proposed the existence of three distinct subgroups of bipolar 1 disorder based on age at onset (AAO). The present study aims to investigate potential clinical and functional differences between these subgroups in an Australian sample.

Participants (n = 239) were enrolled in the Bipolar Comprehensive Outcomes Study (BCOS), a 2-year longitudinal, observational, cross-sectional study. Assessment measures included the Young Mania Rating Scale (YMRS), Hamilton Depression Rating Scale (HAMD21), Clinical Global Impressions Scale (CGI-BP), SF-36, SLICE/Life Scale, and the EuroQol (EQ-5D). Participants were also asked about their age at the first major affective episode.

Three AAO groups were compared: early (AAO < 20, mean = 15.5 ± 2.72; 44.4% of the participants); intermediate (AAO 20–39, mean = 26.1 ± 4.8; 48.14% of the participants) and late (AAO > 40, mean = 50.6 ± 9.04; 7.4% of the participants). Higher rates of depression, suicidal ideation and binge drinking were reported by the early AAO group. This group also reported poorer quality of life in a number of areas. The early AAO group had a predominant depressive initial polarity and the intermediate group had a manic predominance.

Early AAO is associated with an adverse outcome.

To provide a selected overview of the literature on psychosocial treatments for bipolar disorder

Selective literature review

Randomised controlled trials of psychosocial interventions in bipolar disorder fall largely into five categories, namely: psychoeducation, integrated treatments, family based therapy, cognitive behavioural therapy and interpersonal social rhythm therapy. Most studies have shown some benefit in terms of relapse prevention, but have tended to be effective for either the depressed or the manic pole, and not both. Broader outcome parameters such as quality of life have not been reported consistently. The mechanisms whereby treatments might exert their effects have not been clearly delineated. Many studies have excluded patients with bipolar II and other variants, and those with psychiatric and substance use comorbidities, reducing their generalisability.

Whilst psychosocial treatments show promise in the area of bipolar disorder, more work is required to delineate the effective elements of such interventions, and to ensure generalisability to individuals with bipolar II and other forms of bipolar disorder, as well as those with psychiatric and substance use comorbidities. Other forms of delivery, such as via the internet, deserve further exploration.

Psychosocial interventions have the potential to enhance relapse prevention in bipolar disorder.

To evaluate a manualised group-based intervention for people with bipolar disorder in a naturalistic setting.

Eighty-four participants were randomised to receive the group-based intervention (a 12-week programme plus three booster sessions) or treatment as usual, and followed up with monthly telephone interviews (for 9 months post-intervention) and face-to-face interviews (at baseline, 3 months and 12 months).

Participants who received the group-based intervention were significantly less likely to have a relapse of any type and spent less time unwell. There was a reduced rate of relapse in the treatment group for pooled relapses of any type (hazard ratio 0.43, 95% CI 0.20–0.95; t343 = −2.09, P = 0.04).

This study suggests that the group-based intervention reduces relapse risk in bipolar disorder.