Introduction

Dependence is not merely an individual’s personal tragedy; it also involves those closest to them, inevitably drawing them into its intense vortex and engages emotionally, psychologically and socially those who attempt to rescue, control, justify or understand. Tomasz Rejent likened the problem of addiction to “an elephant standing in the middle of the room of a family gathering” [1: 36].
The problem of dependence thus becomes the central point of the lives of significant others – enormous, overwhelming, though often unspoken. Close relatives of someone with substance use disorders begin to focus all their energy on attending to this “elephant”, gradually neglecting their own needs and boundaries. Very often, as emphasised by Polish researchers, these significant others are partners [2], parents [3, 4] and children of indivi­duals struggling with dependence [5]. As indicated by the considerations of Orford et al. [6] on so-called “affected family members”, the consequences of dependence encompass a wide spectrum of psychological, social and economic harm borne by all close individuals, regardless of their role (parent, partner, child or sibling) within the family system. However, how siblings fit into this picture remains relatively underrepresented in Polish research.

At the same time, it should be mentioned that the situation is somewhat different in the English- language literature. Although this issue appears in the subject literature and in academic theses, and the number of studies devoted to sibling experiences is gradually increasing, which is understandable given the complexity and sensitivity of this issue; the sibling experience is often treated as one element of broader studies on the functioning of the whole family affected by dependence. At the same time, despite the growing number of publications in recent years, the number of in-depth, systematic analyses directly focused on siblings remains relatively limited, particularly when it comes to quantitative and comparative studies. Consequently, the picture of the situation of siblings of people with substance-use disorders may remain fragmentary and insufficiently distinguished within the subject literature.

The aim of this article is therefore to analyse and synthesise the existing knowledge on the experiences of siblings of those with substance-use disorders, with particular emphasis on family roles, psychosocial consequences and the dynamics of relationships with the addicted sibling. The article also seeks to organise and distinguish recurring behavioural patterns discussed in the literature like over-responsibility, emotional invisibility, the experience of grief and relational ambivalence, as well as to draw attention to the complexity and multidimensionality of this issue in the existing research. The main research focus is therefore how the experiences of siblings of individuals with substance use disorders are conceptualised in the existing scientific literature, and what main patterns and descriptive categories can be identified within it.

Material and methods

Search strategy

The scientific databases of the Web of Science, Scopus, PubMed (MEDLINE) as well as the Polish Medical Bibliography were used in the search for materials for the narrative literature review. Additionally, Google Scholar was used as a supplementary tool in order to identify hard-to-access litera­ture as well as theses and reports. The language of publication was limited to English, which resulted from the limited representation of this issue in the Polish-language literature. The time frame was from 1992 to 2025.

Search queries

The search employed combinations of keywords in which synonyms of siblings (siblings OR “brothers and sisters”) were combined with syno­nyms of addiction (substance use disorder OR addiction OR “drug abuse” OR “substance misuse”) using the AND operator (i.e., logical AND).

Inclusion/exclusion criteria

The retrieved publications were verified and qualified for further analysis if they met the following inclusion criteria: scientific studies published between 1992 and 2025, available in English, addressing the experiences of siblings of indivi­duals with substance use disorders, and referring to the psychosocial aspects of their functioning (including family relationships, social roles and emotional consequences). Both qualitative and quantitative studies, as well as review papers, were included.

Individual publications were excluded from the review due to failure to meet the inclusion criteria. Additionally, one theoretical publication [7] was used as supplementary literature to contextua­lise sibling relationship dynamics though was not included in the final count of analysed studies.

Selection of studies

Following verification of the texts and the application of the inclusion and exclusion criteria,  28 publications were qualified for the final analysis.

In the Table I, the studies included in the present review are presented, indicating their authors, year of publication, applied technique and study-sample characteristics. It should also be noted that in some of the cited studies, other family members were included in the analysis; however, in the present paper, only data on siblings has been taken into account and distinguished.

Review of existing knowledge

It should be noted that a substantial majority of the analysed studies were qualitative, which influences how conclusions are formulated and limits the scope for quantitative generalisation. After organising the analysed studies according to authors, methodology and sample characteristics, a narrative review of the publications presented in the Table I was conducted.

During the analysis, recurring themes concerning the experiences of siblings of individuals with substance use disorders emerged and were grouped into four main categories: “Trapped in over-responsibility”, “Life in the shadow of addiction”, “Siblings’ grief in response to the symbolic or actual loss of a sibling in the course of addiction” and “Between loyalty and distance: ambivalence in relationships with an addicted sibling”.

Trapped in over-responsibility

Analysis of English-language studies suggests that siblings of individuals struggling with dependence often function in roles that extend beyond normative sibling relationships. Tsamparli and Frrokaj [8] describe this phenomenon as a relationship in which many non-using siblings in the studied group perceived their addicted brother or sister as particularly “vulnerable” and “susceptible to harm”, which was associated with adopting caregiving and, at times, quasi-parental roles towards them. This process was long-term in nature and could occur at the expense of the siblings’ own needs [8].

The study by Incerti et al. [9] shows that the experience of living in a family affected by a sibling’s dependence may foster the internalisation of the belief that one’s own needs are secondary to caregiving responsibilities. In many participants’ narratives, a strong sense of responsibility and a need to protect both parents and siblings was evident, which often led to emotional tension and conflict. Some participants also described pressure to adopt the role of the “good daughter”, understood as the expectation to function in a problem-free, overly mature and family-oriented manner. Moreover, acceptance of the sibling with substance-use disorders was described as a stance involving tolerance in crisis situations, reduced moral judgement, and an attempt to understand the conditions underlying substance use [9].

Dykes and Casker [10] highlight, in turn, the material and practical dimension of “over-responsibility”. In their study, siblings of individuals with substance-use disorders often bore financial costs related to the consequences of the dependence and became involved in meeting the basic needs of their sibling’s children. As the authors indicate, these actions were motivated by attempts to “rescue” the affected relative and to maintain family system stability. At the same time, they may paradoxically have contributed to the reinforcement of maladaptive relational patterns and to increased feelings of frustration, helplessness and overload. Participants described their experiences as emotionally exhausting, leading to chronic fatigue and a gradual erosion of psychological resources [10].

Schultz and Alpaslan [11] additionally demonstrate that siblings cohabiting with a substance- using brother or sister often become deeply involved in regulating everyday family functioning. Parti­cipants described adopting monitoring and protective behaviours aimed at reducing the harmful consequences of substance use within the household, while simultaneously struggling with chronic emotional strain, fear and relational tension [11]. These findings further support the conceptualisation of siblings as “hidden carers” within families affected by dependence.

This phenomenon may be interpreted in theo­retical terms in light of the concept of “hidden carers” proposed by Barnard [12]; family members, includ­ing siblings, assume significant caregiving responsibilities towards a person experiencing addiction, while their role remains formally unre­cognised and insufficiently supported by systemic interventions.

Gabriel [13], in turn, points to the occurrence of so-called survivor’s guilt among siblings of dependent individuals. This is associated with the belief in the “privileged” position of the non-using sibling and with reflection on inequalities of experience within the family system. Gabriel also notes that some participants pursued studies in psychology or chose careers in uniformed services (e.g., the police) and helping professions, interpreting these choices as a continuation of the role of the “hero” or of a person responsible for solving various problems in interpersonal relationships [13].

Recent qualitative studies further deepen the understanding of over-responsibility among siblings of individuals with substance use disorders. Løberg et al. [14] describe how siblings often attempted to maintain family stability and emotional balance prior to their sibling’s drug-related death. Participants reported constant vigilance, emotional monitoring, and efforts to protect both the addicted sibling and other family members from escalating crises. These experiences were associated with chronic emotional burden and a persistent sense of responsibility for preserving the functioning of the family system [14]. Similarly, Lorås et al. [15] indicate that siblings frequently adopted protective and caregiving roles within the family while simultaneously suppressing their own emotional needs. The authors emphasise that these dynamics often contributed to emotional exhaustion, loneliness, and difficulties in establishing personal boundaries [15].

Life in the shadow of addiction

One of the most frequently recurring themes in the analysed publications is the experience of emotional invisibility among siblings of indivi­duals with substance-use disorders. Clarfield [16] synthesises this phenomenon already in the title of her work: “You’re Doing Fine, Right?” on the experience of emotional marginalisation and the social assumption that the absence of addiction equates to the absence of genuine difficulties. The author describes this phenomenon as a form of invalidation and emotional erasure, in which siblings’ suffering remains unseen and unacknowledged. Stress, anxiety and feelings of confusion are overlooked as the attention of both the family system and often institutional systems is focused almost exclusively on the individual with substance-use disorders [16]. As a result, siblings function in the shadow of the problem, experiencing a form of emotional invisibility; their experiences are marginalised not because they are less intense, but because they do not fit into the dominant narrative of suffering within the family.

A broader systemic perspective on these experiences is provided by the meta-ethnography conducted by Lindeman et al. [17], which conceptualises problematic substance use within the family as an “unknown invisible intrusion” disrupting everyday family life, emotional security and interpersonal relationships. The authors describe how family members adapt their daily functioning to the unpredictability of addiction, often reorganising routines, communication patterns and emotional expression around the addicted person’s behaviour [17]. Although the study concerns family members more broadly, its findings help contex­tualise siblings’ experiences of emotional invisi­bility, chronic tension and instability within the family environment.

Greif and Woolley [18] draw attention to the institutional dimension of the invisibility of siblings of individuals with substance use disorders. The authors indicate that in therapeutic practice and dependence treatment protocols, attention is primarily focused on the person with a substance-use disorders and their parents or partner, while siblings’ experiences are insufficiently considered [18].
Consequently, siblings remain at the margins of the support system, despite also experiencing significant emotional burdens. Smith-Genthôs et al. [19] further conceptualise siblings of individuals with substance use disorders as a frequently overlooked group within both family systems and institutional responses to dependence. Their findings suggest that siblings may experience a form of secondary marginalisation, in which their emotional distress becomes overshadowed by the needs and crises associated with the addicted family member. This may contribute to feelings of invisibility, isolation and insufficient access to emotional support [19]. This form of structural invisibility does not indicate an absence of lived experience but rather its limited recognition within institutional discourse, which may foster the internalisation of the belief that one’s own difficulties are secondary and that one must independently cope with the consequences of dependence within the family.

This experience is further intensified in the context of the social stigma surrounding dependence. Gabriel [13] and Clarfield [16] indicate that siblings of individuals with substance-use disorders often experience pressure to keep family problems secret, which limits their ability to openly share difficulties in social relationships. In many participants’ narratives, a tendency also emerges to avoid disclosing the family situation due to fear of social judgement and misunderstanding from others. As a result, as may be inferred from these studies, interpersonal relationships narrow, while feelings of loneliness and isolation may become persistent [13, 16].

There are also some interesting observations in the quantitative study by Çukurova et al. [20], who report differences in cognitive functioning between siblings of individuals with substance- induced psychotic disorder and a control group (without such family burden). The findings suggest a reduced efficiency in response inhibition and verbal fluency as well as an analysis of clinical risk for the development of psychosis. The authors interpret these results in the context of potential neurocognitive difficulties that may co-occur with the burden of functioning in a family affected by dependence [20].

Additionally, the findings of Swinton [21] and Lindeman et al. [22] indicate that growing up in the context of a sibling’s dependence is associated with a variety of adaptive strategies. In participants’ narratives, both a strong orientation towards avoiding psychoactive substances and reflections suggesting an ambivalent attitude towards their use appear. The authors emphasise that the experience of living in a family affected by dependence may influence attitudes towards substances; however, the heterogeneity of individual experiences precludes clear generalisations [21, 22].
In turn, the study by Low et al. [23] indicates that psychoactive substance use by older siblings may serve as a model for imitation, which promotes the normalisation of substance use among younger siblings and may be associated with direct or indirect access to substances [23]. Moreover, the quantitative study by Luthar et al. [24] found that siblings of individuals with opioid addiction are characterised by higher levels of psychoactive substance use compared to the general popu­lation. These findings therefore indicate a clear tendency towards increased risk of substance use behaviours in this group. Similar conclusions arise from register-based analyses by Kendler et al. [25],
covering tens of thousands of sibling pairs, which demonstrated significant familial aggregation of substance use disorders and elevated risk among siblings of individuals with alcohol and drug-use disorders. The authors also indicate that the co-occurrence of other mental disorders like depression or antisocial personality traits further increases this risk [25].

Dykes and Casker [10] observed that siblings of individuals with substance-use disorders may experience a strong sense of danger arising both from aggressive behaviours, including violence from the addicted brother or sister, and from the unpredictability of the home environment related to the presence of non-family individuals in the family space. Experiences of this kind may, in turn, translate into increased tension and a reduced sense of safety in everyday functioning [10].

Siblings’ grief in response to the symbolic or actual loss of a sibling in addiction

A noteworthy observation is that the emotional isolation of siblings is sometimes interpreted in the literature as a form of so-called anticipatory grief, understood as a gradual experience of the loss of earlier closeness, reciprocity and predictability within the relationship. Tsamparli and Frrokaj [8], as well as Incerti et al. [9], describe that changes in the behaviour of the addicted person like withdrawal, aggression or unpredictability may be experienced by siblings as a symbolic loss of the “former” relationship. This process, as indicated by the authors, may trigger grief-like reactions accompanied by sadness, feelings of helplessness and a sense of irreversibility of change. The researchers emphasise that limited social reco­gnition of this form of loss may hinder its processing [8, 9]. The findings of Løberg et al. [14] additionally suggest that the grieving process among siblings may begin long before the actual death occurs. Participants described living in a prolonged state of emotional anticipation, uncertainty and fear connected with the progressive deterioration of their sibling’s condition. Maintaining everyday family life while simultaneously preparing for the possibility of death created a persistent tension between hope and resignation [14]. In a related study, Lorås et al. [15] observed that family relationships prior to a sibling’s drug-related death were often characterised by instability, emotional chaos and attempts to maintain relational cohesion despite repeated crises [15]. Funk et al. [26] further note that siblings’ experience of grief is socially less recognised and less often acknowledged than in the case of parents, which may additionally affect  the way it is experienced and expressed.

The study by Jokipii and Aho [27], based on a systematic review of siblings’ experiences of individuals who died due to psychoactive substance use, further indicates that this group is still rela­tively rarely included in empirical analyses. The authors emphasise that the experience of grief is often long-lasting and complex, and its course is further complicated by the social stigmatisation of drug-related death, which contributes to limited recognition and support from the surrounding environment [27].

Additionally, the literature review (including Lambert et al. [28], Templeton et al. [29] and Title­stad et al. [30]) proposes that grief following the death of a person due to substance use often has a prolonged trajectory and may begin even prior to the actual death, due to the progressive deterioration of the relationship during the course of addiction. Studies by Lindeman et al. [22], Meen  et al. [31], and Jokipii and Aho [27] further show that the relationship with the sibling does not come to a complete end after their death, but rather takes the form of a symbolic relationship, maintained through memory, reflection and attempts to make sense of the experience of loss.

Between loyalty and distance: ambivalence in relationships with an addicted sibling

Relationships with a brother or sister affected by dependence are often described as the coexistence of opposing experiences; on the one hand love, loyalty and a sense of responsibility, and on the other anger, disappointment and the need for distance. The studies by Garney [32] and Ólafsdót­tir [33] indicate that repeated experiences of breached trust, lies and boundary violations lead to a gradual erosion of trust, resulting in sibling withdrawal, which is interpreted as a form of self-protection against further emotional harm [32, 33].

Myers [7] additionally notes that adult sibling relationships are characterised by a unique combination of voluntariness and permanence. Although siblings may experience conflict, emotional distance or dissatisfaction within the relationship, the bond itself often remains psychologically and socially significant due to shared family history and enduring expectations of loyalty. This perspective may help explain why siblings of people with substance-use disorders frequently continue to maintain emotional involvement despite repeated experiences of disappointment, exhaustion or relational strain [7].

As Ólafsdóttir emphasises, hostility and anger expressed by siblings do not necessarily indicate a rupture in the bond though they often express emotional overload and concern for the well-being of the entire family system, particularly the parents. In participants’ narratives, boundary-related statements also appear, reflecting helplessness in the face of progressive dependence. An example is a participant’s statement reported by Ólafsdóttir, expressing regret over the existence of the sibling and suggesting that their absence could constitute a “solution” to the difficult family situation [33]. In this context, intense emotions such as anger or hostility may be interpreted as functioning as a defence mechanism directed not so much at the addicted person, but rather at the destructive consequences of their behaviour.

McAlpine [34] points out that the quality of the sibling relationship prior to the onset of dependence constitutes an important context for later caregiving involvement during dependence. In participants’ narratives, close and supportive pre-existing relationships were associated with more frequent engagement in intensive forms of support for the addicted sibling, alongside attempts to intermittently distance oneself and establish emotional boundaries. This configuration of experiences, as described by participants, was associated with feelings of tension and being “stuck” resulting from a conflict between loyalty to the sibling and the need to protect one’s own well-being [34].

One of the key adaptive challenges in relationships with an addicted sibling concerns the issue of boundary setting. Gabriel [13] and McAlpine [34] describe that attempts by siblings to establish boundaries are often in tension with parental attitudes, as parents, driven by helplessness and fear for the child’s life, may tend to acquiesce to the addicted person’s demands. In participants’ narratives, this gives rise to experiences of interpretative conflict within the family system, contributing to feelings of chaos and moral uncertainty. At the same time, in accounts of adult siblings, a belief emerges in the relative right to withdraw from the relationship; however, decisions of this kind are often accompanied by strong feelings of guilt and shame [13, 34].

Conclusions

1. The experiences of siblings of people with substance-use disorder are complex and multidimensional, encompassing both emotional burdens and changes in social and family functioning.

2. Siblings often adopt roles extending beyond normative sibling relationships, including caregiving and quasi-parental roles, which are associated with an excessive sense of responsibility and the sacrifice of their own needs.

3. Functioning in a family affected by dependence fosters the internalisation of the belief that one’s own experiences are secondary and that adap­tation to the needs of the family system is ne­ces­sary.

4. The experience of “emotional invisibility” constitutes a significant aspect of siblings’ functioning, both in the family and institutional context.

5. Social stigma surrounding dependence contri­butes to siblings’ isolation and limits their ability to disclose and process their own experiences.

6. Life in the shadow of dependence is associated with elevated levels of stress, perceived danger and unpredictability, which may affect a sense of safety and cognitive performance.

7. These experiences may shape diverse attitudes towards psychoactive substances ranging from avoidance to an increased risk of use.

8. Relationships with an addicted sibling are often characterised by ambivalence, combining loyalty and care with the need for distance and the protection of personal boundaries.

9. The gradual loss of the sibling relationship may take the form of anticipatory grief and in the case of death, a complex and socially insufficiently recognised form of bereavement.

10. Recent qualitative studies additionally indicate that siblings often attempt to preserve family cohesion and emotional stability prior to a sibling’s drug-related death, which may intensify long-term emotional burden and anticipatory grief experiences.

11. Establishing boundaries in relationships with an addicted person constitutes a significant but challenging adaptive task, often accompanied by feelings of guilt and loyalty conflict.

12. Siblings of those with substance-use disorders remain a group still insufficiently addressed within support systems that, despite a growing body of literature, remain relatively underrepresented in scientific research, particularly in quantitative and comparative studies.

13. The findings highlight the need for structured psychosocial support for siblings of people with substance-use disorders, including psychoeducational interventions, sibling-inclusive family therapy approaches, access to psychological counselling, peer support programmes, and systematic recognition of siblings within dependence treatment and family support services.

Conflict of interest/Konflikt interesów

None declared./Nie występuje.

Financial support/Finansowanie

None declared./Nie zadeklarowano.

Ethics/Etyka

The work described in this article has been carried out in accordance with the Code of Ethics of the World Medical Association (Declaration of Helsinki) on medical research involving human subjects, Uniform Requirements for manuscripts submitted to biomedical journals and the ethical principles defined in the Farmington Consensus of 1997.

Treści przedstawione w pracy są zgodne z zasadami Deklaracji Helsińskiej odnoszącymi się do badań z udziałem ludzi, ujednoliconymi wymaganiami dla czasopism biomedycznych oraz z zasadami etycznymi określonymi w Porozumieniu z Farmington w 1997 roku.