Bipolar disorder (BD) significantly impacts not only the diagnosed individual but also their informal carers, who experience increased stress, anxiety, and depressive symptoms. While the burden on carers of individuals with mental health disorders has been studied, the lived experience of caring specifically for someone with BD remains under-researched, particularly in the Australian context. In Australia, an estimated 1.3% of the population will experience BD in their lifetime, leading to cyclical mood swings between mania/hypomania and depression. The unpredictable nature of these shifts creates significant challenges for carers, impacting their quality of life. Existing research often focuses broadly on mental health carers, rather than addressing the unique aspects of caring for someone with BD. International research has touched upon carer burden, highlighting issues like financial stress due to impulsive spending during manic phases, relationship strain, increased risky behaviours (substance use), and the distress associated with suicidal ideation and hospitalizations during depressive phases. In Australia, the majority of informal carers are women, exacerbating the burden. Carers experience increased psychiatric symptoms, with depression being most prevalent, often linked to perceived stigma and reduced social support. Current interventions, primarily focused on psychoeducation (in-person and online), have shown some benefit but require further investigation regarding long-term effects and optimal delivery methods. This study aimed to address this gap by exploring the experiences, coping mechanisms, and support needs of Australian informal carers of individuals with BD, incorporating diverse carer roles (partners, parents, children, friends).

Existing literature demonstrates a significant burden on caregivers of individuals with mental health disorders, particularly those with bipolar disorder (BD). Studies show high levels of distress among BD caregivers, impacting various aspects of their lives—emotional, financial, physical, and social. Qualitative research highlights carer isolation, stigma, and the need for greater inclusion in decision-making processes. While some international studies have explored the experiences of BD carers, research in the Australian context is limited. Existing studies have shown that carer burden varies, influenced by individual, social, and organizational factors, including financial strain, relationship dynamics, relapse anxiety, and depressive symptoms. The unique challenges of caring during manic and hypomania phases, marked by impulsive spending, risky behaviors, and relationship strain, have received some attention but require further investigation. The impact of the unpredictable nature of BD symptoms on carers' mental and physical health, their coping mechanisms, and their need for various forms of support (psychoeducation, practical, and emotional) are key themes emerging from previous research. The limitations of existing psychoeducational interventions, including the duration of benefits and optimal delivery methods, point to the need for more effective and accessible support systems.

This qualitative study employed a phenomenological approach to explore the lived experiences of informal carers of individuals with BD in Australia. Participants were recruited purposively through social media advertising (Facebook) after completing an online survey. Inclusion criteria required participants to be current carers of someone with a DSM-5 diagnosis of BD, aged 18 years or older, and residing in Australia; exclusion criteria involved insufficient English proficiency. A total of fifteen semi-structured phone interviews (21-49 minutes each) were conducted with carers, covering topics like background information, experiences, coping mechanisms, information needs, and ideas for program development. The interviews were transcribed verbatim using a professional transcription service. Data analysis used Braun and Clarke's reflexive thematic analysis framework, involving independent coding and discussion amongst the three researchers (including bracketing to avoid bias) to identify themes. NVivo software was used to manage the data, and the final thematic analysis generated five key themes representing carer experiences.

Thematic analysis revealed five key themes: 1. **Separation of the disorder and the person:** Many carers emphasized the importance of distinguishing the person from their illness to maintain a positive relationship and preserve their own well-being. They described strategies for coping with challenging behaviors by acknowledging the illness as the source rather than the person's inherent character. 2. **Carer health and coping strategies:** All participants reported negative impacts on their mental and physical health, including increased anxiety, depression, stress, and fatigue. Some experienced exacerbations of pre-existing conditions, while others developed new mental health problems. Many turned to unhealthy coping mechanisms (e.g., overeating, alcohol use), highlighting the urgent need for self-care strategies. Participants reported that self-care, including exercise, social interaction, creative activities, and boundary setting were vital for maintaining their wellbeing. 3. **Unpredictability and variability of symptoms:** The unpredictable and fluctuating nature of BD symptoms presented a major challenge. Participants described various difficult behaviors including suicidal ideation, violence, anger, sexual indiscretions, and financial impulsivity. The constant uncertainty led to hypervigilance, anxiety, and a sense of being constantly on edge. Despite the negative experiences, some carers reported increased empathy, compassion, and patience as a result of their caring role. 4. **Carer disillusionment and silencing:** Carers expressed feelings of disillusionment with the lack of support from friends, family, and healthcare professionals. They felt their needs were frequently overlooked, with the focus primarily on the individual with BD. Stigma, unhelpful responses from others, and concerns about confidentiality contributed to many carers remaining silent about their experiences. 5. **Story sharing and support needs:** Participants strongly advocated for increased support for carers, emphasizing the need for practical information (medication, emergency plans, symptom management), online and in-person support groups, psychological skills training (stress management, boundary setting), financial assistance, and peer support specifically from other BD carers. The importance of sharing personal stories and learning from the experiences of others was also highlighted.

This study underscores the chronicity and complexity of caring for someone with BD, emphasizing the unique challenges posed by the unpredictable and variable nature of symptoms. The findings diverge from studies of caregivers of individuals with other mental health conditions or chronic illnesses due to this unpredictability and the significant impact on carers' wellbeing. The high levels of stigma surrounding BD, resulting in carer silence and reluctance to seek support, mirrors findings in research on carers of individuals with methamphetamine use or schizophrenia. The study's semi-structured interview approach facilitated the sharing of previously unacknowledged experiences, potentially offering therapeutic benefits in itself. Future support programs should incorporate opportunities for story sharing and peer support to combat isolation and stigma. The study's strengths include its Australian focus, the diverse range of carer roles and types of BD represented, and its in-depth exploration of carer experiences. Future research could focus on specific carer relationships (e.g., romantic partners) to refine understanding of diverse experiences.

This study reveals the substantial burden faced by informal carers of individuals with BD, highlighting the cyclical and unpredictable nature of the illness and its impact on carers' mental and physical health. The pervasive stigma surrounding BD leads to carer silence and limited access to appropriate support. Increased awareness of carers’ needs, along with the development of comprehensive, accessible, and tailored support programs (including online CBT interventions, peer support, and practical assistance) are urgently needed. Future research should investigate the effectiveness of specific interventions and further explore the unique experiences of different types of carers.

The exclusion of non-English speakers limits the generalizability of the findings, potentially underrepresenting the experiences of culturally diverse carers. The Australian-only sample restricts the applicability of the findings to other contexts. The absence of Aboriginal or Torres Strait Islander participants limits the representation of Indigenous perspectives on caring for individuals with BD.