Introduction: Two Conditions Wearing Each Other’s Clothes
Of all the mental health conditions that co-occur with substance use disorders, anxiety is the most common — and among the most clinically complex to treat. Anxiety and addiction do not simply exist alongside each other. They actively reinforce each other through shared neurobiological pathways, through the behavioural patterns each condition produces, and through the vicious cycle of using substances to relieve anxiety and then experiencing worse anxiety as a consequence.
Understanding this cycle — how it develops, what maintains it, and what is required to interrupt it — is one of the most practically important things someone can understand about either condition. It is also the foundation of why integrated dual diagnosis treatment is not a clinical premium: it is the minimum standard of care for anyone presenting with both anxiety and addiction.
For the broader context of how mental health conditions shape addiction, see our pillar on why addiction happens: trauma, stress, and mental health. For more on dual diagnosis treatment specifically, see our resource on dual diagnosis and addiction recovery.
How Common Is the Anxiety-Addiction Co-Occurrence?
The co-occurrence of anxiety disorders and substance use disorders is among the most consistently documented findings in psychiatric epidemiology.
The Australian Bureau of Statistics (ABS) National Study of Mental Health and Wellbeing found that among Australians with a substance use disorder, anxiety disorders are the most prevalent co-occurring mental health condition. The AIHW reports that people presenting for AOD treatment in Australia show rates of anxiety disorders substantially higher than the general population.
Anxiety disorders include a range of presentations — generalised anxiety disorder (GAD), social anxiety disorder, panic disorder, specific phobia, and agoraphobia — as well as PTSD, which shares significant clinical overlap with anxiety. Each of these co-occurs with substance use disorders at elevated rates, with social anxiety and GAD among the most common in alcohol and benzodiazepine use disorder presentations specifically.
The relationship is not coincidental. It is mechanistic — driven by overlapping neurobiological vulnerabilities, shared stress system dysregulation, and the functional role that substances play in temporarily managing anxiety symptoms.
The Neurobiological Overlap
Anxiety and addiction share neurobiological architecture in ways that make their co-occurrence both predictable and mutually reinforcing.
The HPA axis and stress system — Both anxiety disorders and substance use disorders involve dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis — the brain’s primary stress response system. Chronic anxiety produces elevated baseline cortisol and hyperactivated amygdala responses. Chronic substance use further dysregulates this system, raising the stress set point and making the person more reactive to threat and less able to return to calm. Each condition worsens the other’s neurobiological substrate.
The GABA system — Gamma-aminobutyric acid (GABA) is the brain’s primary inhibitory neurotransmitter — the neurochemical that quiets arousal and anxiety. Alcohol and benzodiazepines both enhance GABA activity, producing their characteristic calming, anxiolytic effects. This is why these substances are so effective at relieving anxiety in the short term. Over time, however, chronic alcohol or benzodiazepine use causes the brain to downregulate its own GABA production and receptor sensitivity — meaning that baseline anxiety increases as the brain compensates, driving escalating substance use to maintain the same anxiolytic effect.
The dopamine reward system — Many people with significant anxiety use stimulants — cocaine, methamphetamine, or prescription stimulants — to override the social and motivational inhibition that anxiety produces. Dopamine activation produces the confidence, social ease, and reduced inhibition that the anxious brain cannot generate naturally. This is a neurochemical substitution that works briefly and at significant long-term cost to both the dopamine system and the anxiety disorder.
The prefrontal cortex — Anxiety disorders are associated with hyperactivated threat-detection (amygdala) and relatively underactive prefrontal regulation. Chronic substance use further impairs prefrontal function, reducing the cognitive capacity to manage anxiety through rational self-regulation — driving greater reliance on substances for the emotional management the prefrontal cortex can no longer adequately provide.
The Anxiety-Addiction Cycle
The clinical picture of anxiety and addiction together is best understood not as two parallel conditions but as a self-reinforcing cycle with several distinct and interlocking loops.
Loop 1: Relief-Driven Use
The most straightforward loop: the person experiences anxiety, uses a substance that provides temporary relief, and the relief reinforces the substance as an effective coping strategy. Over time, the substance becomes the primary — eventually the only — means of managing anxiety. This is negative reinforcement in its clearest form: behaviour (substance use) is maintained by the removal of an aversive state (anxiety).
This pattern is particularly common in:
- Alcohol and social anxiety — alcohol lowers inhibition, reduces self-consciousness, and allows social engagement that the anxious person genuinely struggles with without it. Over time, the ability to socialise at all becomes contingent on alcohol.
- Cannabis and generalised anxiety — cannabis reduces ruminative worry in the short term, making it a functional anxiety management tool. Over time, baseline anxiety increases and tolerance develops, requiring more cannabis for less relief.
- Benzodiazepines and panic disorder — even clinically prescribed benzodiazepines can produce iatrogenic dependence that maintains and worsens the anxiety disorder they were prescribed to treat.
Loop 2: Withdrawal-Driven Anxiety
The withdrawal from anxiolytic substances — alcohol, benzodiazepines, cannabis — produces anxiety that is often more severe than the anxiety that preceded use. This withdrawal-induced anxiety is neurobiologically distinct from the original disorder: it is caused by the rebound of suppressed GABA activity and the HPA axis dysregulation produced by chronic substance use. But to the person experiencing it, it is simply anxiety — often experienced as confirmation that they cannot cope without the substance.
This loop produces one of the cruelest clinical dynamics in addiction medicine: the substance that is causing the anxiety cannot be easily stopped without the anxiety becoming worse before it improves. Without clinical support and an understanding of this mechanism, relapse is almost inevitable.
Loop 3: Consequences That Create New Anxiety
Active addiction generates its own anxieties — financial stress, relationship strain, occupational instability, legal risk, health concerns, and the constant management of concealment. These consequence-driven anxieties layer onto the original disorder and create a multiplying anxiety burden. The substance that began as a solution to anxiety becomes a primary source of it.
Loop 4: Avoidance and Shrinking
Both anxiety disorders and addiction are fundamentally disorders of avoidance. Anxiety drives avoidance of feared situations; substance use enables avoidance by blunting the anxiety that would otherwise deter it or simply making difficult situations tolerable. Over time, the range of situations the person can engage with without chemical assistance narrows. Life contracts. The absence of the substance feels increasingly unmanageable — not because the underlying anxiety has worsened (though it may have), but because the coping skills and the confidence to manage anxiety without substances have atrophied.
Why Treating One Without the Other Fails
The clinical implication of the anxiety-addiction cycle is direct: treating addiction without treating the anxiety disorder reliably fails, and treating anxiety without addressing the substance use rarely holds.
When addiction treatment does not address co-occurring anxiety:
- Anxiety symptoms return or intensify during withdrawal and early sobriety
- The person has no alternative means of managing anxiety at the moment when the substance is removed
- Relapse occurs as a relief behaviour — the person returns to the substance to manage anxiety that has no other treatment
- The treatment episode is recorded as a failure; the person becomes more hopeless about recovery
When anxiety treatment does not address co-occurring substance use:
- Substances continue to blunt and obscure anxiety symptoms, making accurate assessment and effective therapy more difficult
- Substance use may be maintained as a hedge against the anxiety treatment not working
- The neurobiological disruption of active substance use impairs the cognitive engagement required for the psychological therapies most effective for anxiety (particularly exposure-based therapies)
Integrated dual diagnosis treatment — where the anxiety disorder and the substance use disorder are addressed simultaneously by a coordinated clinical team — is not a luxury addition. It is the only clinical model that addresses both legs of the cycle.
HARP’s three-pronged clinical model is built precisely around this integration. The Trauma Specialist Psychologist addresses anxiety, emotional dysregulation, and nervous system hyperarousal at the clinical root — while the Addiction Specialist addresses the behavioural patterns and neurobiological mechanisms of substance use, and the AOD Specialist Counsellor provides substance-specific relapse prevention. These three roles work as a coordinated clinical team — ensuring that anxiety and addiction are treated together, not sequentially. Read more: dual diagnosis and addiction recovery.
What Integrated Treatment Looks Like
For someone with co-occurring anxiety and addiction, effective treatment integrates the following components:
Assessment of both conditions at intake — A thorough psychiatric and AOD assessment that identifies the nature, severity, and functional relationship of the anxiety disorder and the substance use. Understanding which came first, what function the substance serves in relation to the anxiety, and what the neurobiological and trauma drivers are — this is the clinical foundation.
CBT for anxiety and addiction simultaneously — CBT has a strong evidence base for both anxiety disorders and substance use disorders, and its techniques are compatible and complementary. Cognitive restructuring addresses the anxious thought patterns that drive both anxiety and substance-seeking; behavioural experiments reduce avoidance and build anxiety tolerance; exposure work (where clinically appropriate and adequately sequenced) gradually restores the person’s capacity to engage with previously avoided situations without chemical assistance. Read more: CBT for addiction.
DBT skills for emotional regulation — Dialectical Behaviour Therapy’s core skills — mindfulness, distress tolerance, emotion regulation, and interpersonal effectiveness — directly address the emotional dysregulation that underlies both anxiety and addiction. Building these skills is the practical work of replacing substances with functioning.
Medication where indicated — SSRIs and SNRIs have a strong evidence base for anxiety disorders and are compatible with addiction recovery. For people whose anxiety is severe enough to impair engagement with psychological therapy, pharmacological support can be an important adjunct — prescribed and monitored by a GP or psychiatrist with AOD experience.
Trauma processing where relevant — Given the high overlap between anxiety disorders and trauma histories, trauma-informed therapy may be indicated alongside the anxiety and addiction work. See our article on trauma and addiction for more on this dimension.
Ongoing support through high-anxiety situations — Early recovery places the person in precisely the situations that anxiety makes most difficult: unfamiliar environments, difficult conversations, rebuilding relationships, returning to work. Structured support — including peer community, continuing care, and clinical contact — through these transitions is a relapse prevention essential.
Frequently Asked Questions
Which comes first — anxiety or addiction? Both sequences are clinically common. In many cases, an anxiety disorder precedes substance use — the substance is used to manage anxiety symptoms that have been present since adolescence or early adulthood. In others, substance use produces anxiety that was not significantly present before — through HPA axis dysregulation, withdrawal effects, and the accumulation of addiction-related consequences. In practice, the directionality is often less clinically important than the current functional relationship: how is the anxiety driving use, and how is use affecting the anxiety?
Can anxiety disorders be treated effectively during addiction recovery? Yes — and they should be. Delaying treatment for an anxiety disorder until after the addiction is resolved rarely works, because the anxiety is typically one of the primary drivers of relapse. The two are best treated simultaneously by a coordinated clinical team. The timing and sequencing of specific interventions (particularly exposure-based therapies) should be guided by clinical readiness — but addressing the anxiety disorder cannot wait.
Are medications for anxiety safe in addiction recovery? SSRIs and SNRIs — the first-line pharmacological treatments for most anxiety disorders — are generally considered safe and appropriate in addiction recovery, and have no significant dependence potential. Benzodiazepines, which are also used for anxiety, carry significant dependence risk and are generally avoided in people with a history of substance use disorder. The exception is clinical use under close supervision for acute or short-term anxiety management. A GP or psychiatrist with AOD experience should guide medication decisions.
How long does it take to recover from co-occurring anxiety and addiction? Recovery from either condition is a long-term process; recovery from both together typically unfolds over months to years. Anxiety symptoms often intensify in early sobriety before improving as the nervous system recalibrates. Most people see meaningful improvement in anxiety within weeks to months of sustained abstinence supported by appropriate psychological treatment. Full remission of both conditions is achievable for many people and is the clinical goal.
Sources
- ABS — National Study of Mental Health and Wellbeing 2020–21
- AIHW — Alcohol and Other Drug Treatment Services in Australia, 2022–23
- NIDA — Comorbidity: Substance Use Disorders and Other Mental Illnesses
- Koob GF & Volkow ND — “Neurobiology of addiction: a neurocircuitry analysis,” The Lancet Psychiatry (2016)
- Anxiety and Depression Association of America (ADAA) — Substance Use Disorders and Co-Occurring Anxiety Disorders
- Alcohol and Drug Foundation (ADF) — Mental Health and Substance Use
- Australian Psychological Society (APS) — Treatments for Anxiety
- HARP — Dual Diagnosis and Addiction Recovery
- National Alcohol and Other Drug Hotline — 1800 250 015 (free, confidential, 24/7)
This article is reviewed for clinical accuracy and is intended for educational purposes only. It does not constitute medical advice. Please consult your GP, a registered psychologist, or a qualified AOD specialist for personalised guidance.
