A new study (Miola, Tondo, & Baldessarini, 2026), published in the International Journal of Mental Health and Addiction, investigated the prevalence of substance use disorders (SUDs) among a group of 4250 adult participants with mood disorders.
They found that the lifetime prevalence of SUDs was 11.5% in the full group of participants, 22.8% in those with bipolar disorder, and 26.6% in those with bipolar I. This study demonstrates a significant prevalence of SUDs among people with bipolar disorder, affecting around a quarter of these individuals, highlighting a significant need for tailored, integrated treatment.
The 2026 study on SUD and mood disorders at a glance
The study involved a group 4250 adults (1583 men and 2667 women) with a mood disorder, including: [1]
- 839 with bipolar I.
- 676 with bipolar II.
- 2735 with major depressive disorder (MDD).
Participants were assessed for over 14 years, with careful monitoring and data compilation over an almost 5-year period. The researchers aimed to ascertain the prevalence of SUDs among those affected by mood disorders in order to provide a clearer picture of how mental health and substance use intersect. [1]
One quarter of participants with bipolar I had a lifetime history of substance use
This was investigated by assessing the participants’ symptoms and substance use behaviors over an extended period of time, focusing on chronic, clinically significant substance use, as opposed to recreational or occasional use.
The study found that 26.6% of participants with bipolar I had a lifetime history of SUD. This finding proves that over a quarter of this clinical population experiences clinically significant SUDs at some point in their lifetime.
Which substances showed up the most often?
Among all participants, alcohol was the most commonly used substance, with a lifetime rate of 20.9%, cannabis use in 3.29%, opioid use in 0.31%, stimulant use in 0.31%, and benzodiazepine use in 0.02%.
Polysubstance use (the use of more than one substance) occurred in 6.35% of the total group of participants, but in 13.5% of the bipolar group, indicating a much higher prevalence of polysubstance use in this group than in the MDD group. [1]
How common is substance use disorder in bipolar disorder?
This study demonstrates a lifetime prevalence of SUD in 22.8% of those with bipolar disorder. However, the wider literature reports a lifetime prevalence of up to 61% in this population. For example:
- Research by Aguglia et al., 2022, identified a lifetime prevalence of SUD among people with bipolar disorder ranging between 26-43%. [2]
- Literature reviews by Cerullo et al., 2007, indicate that at least 20-40% of this population experiences a co-occurring SUD. [3]
- Data from the National Institutes of Mental Health Epidemiologic Catchment Area Program compiled by Regier et al., 1990, show that drug or alcohol disorders occur in 48-61% of those with bipolar disorder. [4]
These findings demonstrate a serious clinical significance in the prevalence of SUD among people with bipolar disorder. In comparison, SUDs in other populations occur at a prevalence of: [4]
- 17% of the general population.
- 27.2% of those with MDD.
- 47% of those with schizophrenia.
- 84% of those with antisocial personality disorder (ASPD).
These figures demonstrate that individuals with bipolar disorder experience a higher rate of SUD than almost every other mental health condition, second only to ASPD. [3][4]
Substance use in bipolar I vs. Bipolar II
The results of Miola et al. (2026), confirmed by broader psychiatric literature, indicate a significant difference in SUD lifetime prevalence between bipolar I and bipolar II, with prevalence rates of 26.6% and 18.4%, respectively. [1]
Wider research suggests a higher prevalence, estimating around 40-61% for bipolar I, compared to 22-48% for bipolar II. Although the overall percentages differ, all of these studies highlight a clear indication that SUDs are more common among individuals with bipolar I. [2][3][4]
Substances commonly misused with bipolar disorder
Alcohol remains the most commonly misused substance among people with bipolar disorder. Alcohol dependence or alcohol use disorder (AUD) is found to occur in 39- 58% of individuals with bipolar disorder. [4][5]
Cannabis is the next most prevalent substance, with cannabis use disorder affecting roughly 20% of those with bipolar disorder. [5]
Other substances commonly used, albeit with a lower prevalence, among people with bipolar disorder include stimulants such as cocaine, opioids, and benzodiazepines. [1][2][3]
Why bipolar disorder and substance use disorder co-occur
SUDs commonly occur alongside various mental health conditions for two primary reasons: there are often shared underlying causes and risk factors, and substance use is often used as a coping mechanism for emotional distress. [2]
Bipolar disorder causes changes in mood that can be distressing and intense, alternating between severe depression and manic episodes. People with bipolar disorder who use substances often do so to try to manage these mood swings by dulling the extremes or as a form of escape from their overwhelming intensity.
Substance use patterns can vary depending on whether a person is struggling with depressive or manic symptoms. For instance, some people may be more prone to using substances to quell depressive symptoms like low mood and energy levels. Others may go on binges during manic episodes, which are characterized by impulsive and risky choices.
Additionally, bipolar disorder and SUDs share many causal factors, such as genetic, socioeconomic, and environmental factors, traumatic experiences, and personality traits. A combination of these characteristics can significantly increase the risk of co-occurring SUD and bipolar disorder. [2]
What the research suggests about care
This research highlights the need for careful and accurate diagnoses, followed by integrated care pathways for individuals with concurrent SUD and bipolar disorder. Treating either condition in isolation can lead to poorer outcomes due to issues such as non-compliance, drug interactions, and psychosocial issues. [2][3]
As such, treatment should provide integrated dual diagnosis care, tailored to the specific needs of the individual, with a multidisciplinary team providing psychological support and stabilization alongside substance rehabilitation.
Many individuals living with bipolar disorder require medication to help stabilize their symptoms. Various pharmacological approaches have demonstrated effective outcomes in both SUD and bipolar symptoms, including aripiprazole, quetiapine, lamotrigine, and naltrexone. Further research is required to discover the most effective treatment approaches for this population. [3]
When families and patients might consider a dual-diagnosis assessment
A dual diagnosis assessment should be considered when psychiatric treatments alone are not adequately managing mental health symptoms, or when substance use triggers or worsens manic or depressive episodes.
If at any point substance use and mental health symptoms occur concurrently, worsening or exacerbating one another, or there are clear physical and behavioral changes in someone diagnosed with bipolar disorder, it may be necessary to seek a dual diagnosis assessment.
