Which Addictions Are Linked to Which Mental Health Disorders? What the Research Shows

ZorbaCare Research · Evidence review · Medically reviewed by Dr. Sayantani Mukherjee, Psychiatrist · Published October 2026 · 20 references

How to Read the Numbers in This Review

Two kinds of figures appear throughout. Knowing the difference prevents the most common misreadings of addiction research.

• Prevalence is the share of a group who have a condition. “41.7% of people with schizophrenia have a substance use disorder” means roughly four in ten, in the samples studied.
• Odds ratio (OR) compares two groups. An OR of 2.4 means the odds of the condition are about 2.4 times higher in one group than the other. An OR of 1 means no difference. Odds ratios describe association; on their own, they do not prove that one condition causes the other.
• 95% confidence interval (CI) is the range within which the true value plausibly lies. When the interval crosses 1 for an odds ratio, the association is not statistically significant.

Key Findings at a Glance

OR = odds ratio. Percentages are prevalence unless stated. Numbers in brackets refer to the References list.

1. Why Addiction and Mental Illness Travel Together

The U.S. National Institute on Drug Abuse describes three pathways that explain why substance use disorders and other mental disorders so often co-occur [3]. They are not mutually exclusive; in most people, more than one is at work.

1.1 Shared risk factors

Both conditions draw on the same roots: inherited traits, trauma, chronic stress and adverse environments. Genetic studies have identified gene variants shared across addiction disorders, and some of the same brain areas are involved in addiction and in conditions such as ADHD and schizophrenia [3]. On this view, neither condition causes the other; both grow from common soil. Early adversity is a particularly well-studied shared root — we’ve explored it in how childhood experiences shape later addiction.

1.2 Mental illness leading to substance use: the self-medication hypothesis

Psychiatrist Edward Khantzian proposed that many people use substances not to seek pleasure but to relieve suffering. In his formulation, the aim is “relief of dysphoria” rather than the pursuit of euphoria, and he has argued that the more useful clinical question is “What did the drug do for you?” [14][18]. A person with untreated social anxiety may find that alcohol makes social life bearable; a person with unrecognised ADHD may find that a stimulant brings temporary focus. Relief is real but short-lived, and tolerance, withdrawal and consequences eventually deepen the original distress.

1.3 Substance use leading to mental illness

The traffic also runs the other way. Substance use can change the same brain areas that are disrupted in other mental disorders, such as schizophrenia, and can contribute to those disorders or make them worse [3]. Cannabis use, for example, has been linked to earlier onset of psychosis in people with genetic risk factors [3].

1.4 Substance-induced or independent? The chicken-and-egg question

Clinically, one of the hardest questions is whether a person’s depression or anxiety is caused by the substance, or exists independently of it. One key DSM-5 clue is timing: symptoms that began before the substance use, or that persist for about a month after acute withdrawal or intoxication ends, point toward an independent disorder rather than a substance-induced one [15].

This matters, and the answer often surprises families. In the U.S. National Epidemiologic Survey on Alcohol and Related Conditions (NESARC), about 20% of people with a substance use disorder had an independent mood disorder and about 18% an independent anxiety disorder. Separately, fewer than 1% of people with mood or anxiety disorders had episodes that were only substance-induced [16]. This suggests that for most people, the depression or anxiety is not simply a side effect of the substance, and needs to be treated in its own right. (For a broader introduction, see how mental health and substance abuse are connected.)

2. Starting From the Addiction: What Each Substance or Behaviour Is Linked To

2.1 Alcohol → depression and anxiety

Alcohol has the most extensively studied psychiatric associations of any substance. A meta-analysis of epidemiological surveys published between 1990 and 2014 found that people with alcohol use disorders had pooled odds of major depression 2.42 times higher (95% CI 2.22–2.64) and of any anxiety disorder 2.11 times higher (95% CI 2.03–2.19) than those without [2].

The relationship is bidirectional. Alcohol is a depressant of the central nervous system, and its withdrawal produces anxiety; at the same time, people with anxiety often drink to manage it. The pattern is well recognised in clinical practice: anxiety eases briefly with a drink, returns more strongly the next day, and the cycle tightens. Read more on the connection between alcohol and depression and alcohol addiction treatment.

2.2 Illicit drugs → depression and anxiety (stronger still)

The same meta-analysis found even stronger associations for illicit drug use disorders: odds of major depression were 3.80 times higher (95% CI 3.02–4.78) and of any anxiety disorder 2.91 times higher (95% CI 2.58–3.28) [2]. See drug addiction treatment.

2.3 Cannabis → psychosis, and → depression in adolescents

Cannabis is often presented as harmless. For most occasional adult users, serious psychiatric harm is unlikely — but the evidence on frequent, high-potency and early use is clear enough to take seriously.

• Psychosis. The EU-GEI multicentre case-control study found that, compared with never-users, daily cannabis users had about three times the odds of a psychotic disorder (OR 3.2), and daily users of high-potency cannabis nearly five times the odds (OR 4.8, 95% CI 2.5–6.3) [4]. The authors estimated that, if the association were causal, around 30% of new psychosis cases in London and 50% in Amsterdam could have been prevented if high-potency cannabis were not available [4].
• Depression and suicidality. A meta-analysis of longitudinal studies found that cannabis use in adolescence was associated with higher odds of depression in young adulthood (OR 1.37, 95% CI 1.16–1.62), suicidal ideation (OR 1.50) and suicide attempt (OR 3.46, 95% CI 1.53–7.84) [5]. The association with anxiety was not statistically significant (OR 1.18, 95% CI 0.84–1.67) [5].

More: how cannabis affects the brain and cannabis addiction treatment.

2.4 Opioids → depression, anxiety, ADHD and trauma

A 2022 review of 345 studies covering 104,135 people with opioid use disorder found pooled current prevalence of depression at 36.1%, anxiety at 29.1%, ADHD at 20.9%, PTSD at 18.1% and bipolar disorder at 8.7% [6]. Lifetime antisocial personality disorder was found in 33.6% and borderline personality disorder in 18.2% [6]. Chronic pain is a further major overlap: NIDA reports that almost half of people with opioid use disorder also experience chronic pain [3]. See heroin addiction and prescription pill addiction.

2.5 Gambling → nicotine, other addictions, mood and anxiety

Gambling disorder shows high levels of comorbidity. A meta-analysis of population surveys found that among people with problem or pathological gambling, 60.1% had nicotine dependence, 57.5% a substance use disorder, 37.9% a mood disorder and 37.4% an anxiety disorder [7]. The authors recommended screening for co-occurring disorders whenever someone enters treatment for gambling [7]. See gambling addiction treatment.

2.6 Gaming → anxiety, depression and ADHD

Gaming disorder is included as a diagnosis in ICD-11, while DSM-5 lists it only as a condition for further study, and its evidence base is younger. A comprehensive review of studies on internet gaming disorder and pathological video-game use found that, of the significant associations reported across the studies analysed, anxiety accounted for 92%, depression 89%, ADHD 85%, and social phobia or obsessive-compulsive symptoms 75% [8]. These are not prevalence rates — they show how consistently each condition was linked to problem gaming across studies. Most of these studies are cross-sectional, so direction of cause is uncertain: anxious or inattentive young people may retreat into gaming, and excessive gaming may worsen mood and attention. See gaming addiction: symptoms and treatment.

3. Starting From the Diagnosis: Which Mental Health Conditions Carry the Highest Addiction Risk

3.1 ADHD

A meta-analysis of 6,689 patients in substance use treatment found that 23.1% (95% CI 19.4–27.2) met criteria for ADHD [9] — well above estimates for the general adult population. ADHD is often undiagnosed in adults, and impulsivity, restlessness and difficulty with delayed reward all raise addiction risk. Patients with both conditions also report greater drug cravings [3]. Treating the ADHD is part of treating the addiction. See ADHD treatment and ADHD, stimulants and addiction.

3.2 Post-traumatic stress disorder

Data from national U.S. surveys, reported by the National Center for PTSD, show that 46.4% of people with lifetime PTSD also met criteria for a substance use disorder [10]. A second national study found the overlap in 27.9% of women and 51.9% of men with lifetime PTSD [10]. Substances are frequently used to dampen intrusive memories, hyperarousal and insomnia — a clear case of the self-medication pathway. Trauma-focused therapies such as EMDR are central to treating the PTSD. See PTSD treatment.

3.3 Bipolar disorder

A meta-analysis of clinical samples found alcohol use to be the most common comorbidity in bipolar disorder at 42%, followed by cannabis at 20% and other illicit drugs at 17% [11]. Rates were similar in bipolar I and bipolar II, and higher in men [11]. Both conditions need to be assessed and treated together. See bipolar disorder treatment.

3.4 Schizophrenia

Across community and clinical studies from 1990 to 2017, 41.7% of people with schizophrenia-spectrum disorders had a substance use disorder — 27.5% illicit drugs, 26.2% cannabis, 24.3% alcohol and 7.3% stimulants [12]. Men were affected far more often than women (48% vs 22.1%) [12]. See schizophrenia treatment.

3.5 Eating disorders

The overlap is concentrated in disorders that involve bingeing or purging. A review of current evidence reported a pooled substance use disorder prevalence of about 16% in anorexia nervosa — higher in the binge-purge subtype than the restrictive subtype — and a pooled lifetime alcohol use disorder prevalence of 19.9% in binge-eating disorder, about 1.6 times the rate in people without it (RR 1.59) [13][19]. See eating disorder treatment.

3.6 Depression and anxiety

Because they are the most common mental disorders, depression and anxiety account for the largest absolute number of dual diagnoses. NESARC found that almost 20% of U.S. adults with a mood disorder and almost 15% of those with an anxiety disorder also had a substance use disorder [16]. See depression and anxiety and panic attacks.

4. The Indian Picture

India’s most comprehensive data come from the National Mental Health Survey of India, 2015–16, conducted by NIMHANS. Among adults, 22.4% had a substance use disorder when tobacco is included; alcohol use disorder affected 4.6% overall — 9% of men and 0.5% of women [17]. The treatment gap for alcohol use disorders was 86% [17]: the large majority of people who needed treatment did not receive it.

Indian data specifically on co-occurrence — how many people with alcohol use disorder also have depression, for instance — are far thinner than Western data. Most of the pooled estimates in this review come from North American, European and Australian samples. Whether the same ratios hold in India, where patterns of drinking, stigma and access to care differ, is an open research question. For current national figures, see our summary of addiction statistics in India.

5. What the Evidence Means for Treatment

1. Screen for both, every time. Given the prevalence figures above, any assessment for addiction should include a psychiatric assessment, and any assessment for a mental disorder should ask about substances and behaviours such as gambling and gaming.
2. Wait to label, but don’t wait to treat. Because withdrawal itself causes low mood and anxiety, a confident diagnosis of an independent disorder may require around a month of abstinence [15]. Symptoms still need managing during that window.
3. Treat the conditions together. Treating addiction alone leaves the driver of self-medication in place; treating depression alone leaves a substance that worsens it. Integrated care — one team treating both — is the model recommended in clinical guidance, although trial evidence comparing specific approaches is mixed, particularly for people with severe mental illness [3][20]. This is what dual-diagnosis treatment means.
4. Match the therapy to the pairing. Trauma-focused work for PTSD, DBT for emotional dysregulation, CBT for depression and anxiety, and appropriate medical treatment of ADHD and bipolar disorder all have roles.
5. Plan relapse prevention around the underlying condition. Because untreated depression and anxiety are among the reasons people turn to substances in the first place [3][14], aftercare should monitor mental health, not only abstinence. See relapse prevention.

6. Limitations of the Evidence

• Association is not causation. Most figures above are cross-sectional associations. The cannabis–psychosis evidence is among the strongest for a causal contribution, but even there the authors’ population estimates rest on an assumption of causality [4].
• Heterogeneity. Pooled estimates combine studies with different methods, populations and diagnostic tools; several of the reviews cited report substantial variation between studies [5][7].
• Clinical versus community samples. People in treatment tend to have more severe and more numerous conditions than people in the community, so clinical figures (for example, [11]) are higher than population figures.
• Geography. Most data are from high-income Western countries. Indian comorbidity data are limited (see Section 4).
• Behavioural addictions are newer. Gaming disorder in particular has a younger, mostly cross-sectional evidence base [8].

Frequently Asked Questions

Which mental health disorder is most commonly linked to addiction?

Depression and anxiety account for the largest number of co-occurring cases because they are so common. In the U.S. NESARC survey, about 20% of people with a substance use disorder had a mood disorder and about 18% had an anxiety disorder. Proportionally, rates are highest in severe mental illnesses such as schizophrenia, where 41.7% have a substance use disorder.

Does alcohol cause depression, or does depression cause drinking?

Both happen. People with alcohol use disorders have about 2.4 times the odds of major depression. Heavy drinking can produce depressive symptoms, and people with depression may drink to cope. Clinicians usually reassess mood after a period of abstinence: symptoms that persist for about a month after withdrawal ends point to an independent depressive disorder that needs its own treatment.

Can cannabis cause psychosis?

Research strongly links frequent, high-potency cannabis use to psychotic disorder. In a large European study, daily users of high-potency cannabis had about 4.8 times the odds of a psychotic disorder compared with people who had never used cannabis. Risk is highest with daily and high-potency use, and in people with genetic risk factors cannabis has been linked to earlier onset of psychosis.

Why do people with ADHD have higher rates of addiction?

Impulsivity, difficulty with delayed reward and restlessness raise addiction risk, and some people use substances to self-medicate symptoms. A meta-analysis found that 23.1% of people in treatment for substance use disorders have ADHD, which often goes undiagnosed in adults.

What is dual diagnosis?

Dual diagnosis, also called co-occurring disorders, means a person has both a substance use or behavioural addiction and a mental health disorder at the same time. Clinical guidance recommends treating both together by one team, rather than one after the other, because each condition can make the other worse.

References

1. Substance Abuse and Mental Health Services Administration. 2024 National Survey on Drug Use and Health. As reported in: National Association of Counties, “SAMHSA releases new 2024 data on rates of mental illness and substance use disorder in the U.S.”
2. Lai HMX, Cleary M, Sitharthan T, Hunt GE. Prevalence of comorbid substance use, anxiety and mood disorders in epidemiological surveys, 1990–2014: a systematic review and meta-analysis. Drug and Alcohol Dependence. 2015;154:1–13. doi:10.1016/j.drugalcdep.2015.05.031
3. National Institute on Drug Abuse. Co-Occurring Disorders and Health Conditions. Bethesda (MD): National Institutes of Health; updated September 2024.
4. Di Forti M, Quattrone D, Freeman TP, et al. The contribution of cannabis use to variation in the incidence of psychotic disorder across Europe (EU-GEI): a multicentre case-control study. The Lancet Psychiatry. 2019;6(5):427–436. doi:10.1016/S2215-0366(19)30048-3
5. Gobbi G, Atkin T, Zytynski T, et al. Association of cannabis use in adolescence and risk of depression, anxiety, and suicidality in young adulthood: a systematic review and meta-analysis. JAMA Psychiatry. 2019;76(4):426–434. doi:10.1001/jamapsychiatry.2018.4500
6. Santo T Jr, Campbell G, Gisev N, et al. Prevalence of mental disorders among people with opioid use disorder: a systematic review and meta-analysis. Drug and Alcohol Dependence. 2022;238:109551. doi:10.1016/j.drugalcdep.2022.109551
7. Lorains FK, Cowlishaw S, Thomas SA. Prevalence of comorbid disorders in problem and pathological gambling: systematic review and meta-analysis of population surveys. Addiction. 2011;106(3):490–498. doi:10.1111/j.1360-0443.2010.03300.x
8. González-Bueso V, Santamaría JJ, Fernández D, et al. Association between internet gaming disorder or pathological video-game use and comorbid psychopathology: a comprehensive review. International Journal of Environmental Research and Public Health. 2018;15(4):668. doi:10.3390/ijerph15040668
9. van Emmerik-van Oortmerssen K, van de Glind G, van den Brink W, et al. Prevalence of attention-deficit hyperactivity disorder in substance use disorder patients: a meta-analysis and meta-regression analysis. Drug and Alcohol Dependence. 2012;122(1–2):11–19. PubMed 22209385
10. U.S. Department of Veterans Affairs, National Center for PTSD. Co-occurring PTSD and substance use disorder. Figures as summarised by the U.S. Drug Enforcement Administration: “What’s PTSD and how is it connected to substance misuse?”
11. Hunt GE, Malhi GS, Cleary M, Lai HMX, Sitharthan T. Prevalence of comorbid bipolar and substance use disorders in clinical settings, 1990–2015: systematic review and meta-analysis. Journal of Affective Disorders. 2016;206:331–349. doi:10.1016/j.jad.2016.07.011
12. Hunt GE, Large MM, Cleary M, Lai HMX, Saunders JB. Prevalence of comorbid substance use in schizophrenia spectrum disorders in community and clinical settings, 1990–2017: systematic review and meta-analysis. Drug and Alcohol Dependence. 2018;191:234–258. doi:10.1016/j.drugalcdep.2018.07.011
13. Co-occurring substance use and eating disorders. Psychiatric Times. Citing Devoe DJ et al., Journal of Eating Disorders, 2021, and Bogusz K et al., Addiction, 2021.
14. Khantzian EJ. The self-medication hypothesis of substance use disorders: a reconsideration and recent applications. Harvard Review of Psychiatry. 1997;4(5):231–244. PubMed 9385000
15. American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders, 5th ed. (DSM-5). Criteria for substance/medication-induced depressive and anxiety disorders. Summarised in: Ries R, Youdelis-Flores C. Substance-Induced Mood Disorders, University of Washington, 2018.
16. Grant BF, Stinson FS, Dawson DA, et al. Prevalence and co-occurrence of substance use disorders and independent mood and anxiety disorders: results from the National Epidemiologic Survey on Alcohol and Related Conditions. Archives of General Psychiatry. 2004;61(8):807–816. doi:10.1001/archpsyc.61.8.807
17. Gururaj G, Varghese M, Benegal V, et al. National Mental Health Survey of India, 2015–16: Prevalence, Patterns and Outcomes. Bengaluru: NIMHANS; 2016. Summary
18. Khantzian EJ. The theory of self-medication and addiction. Psychiatric Times. 2017.
19. Bogusz K, Kopera M, Jakubczyk A, et al. Prevalence of alcohol use disorder among individuals who binge eat: a systematic review and meta-analysis. Addiction. 2021;116(1):18–31. Record
20. Hunt GE, Siegfried N, Morley K, Sitharthan T, Cleary M. Psychosocial interventions for people with both severe mental illness and substance misuse. Schizophrenia Bulletin. 2014;40(1):18–20. doi:10.1093/schbul/sbt160

This review is for education and general information. It does not replace assessment or advice from a qualified clinician. If you are worried about yourself or someone close to you, speak to a psychiatrist or contact ZorbaCare’s clinical team confidentially. In India, the Tele MANAS mental health helpline is available on 14416.