Substance use disorder is a complex condition involving the use of harmful substances which have the potential to be addictive and harm the physical and mental well-being of a person. Research has shown a high co-morbidity rate (they co-exist together) between drug addiction and mental health illnesses such as depression, bipolar disorder, borderline personality disorder (BPD), and attention deficit hyperactivity disorder (ADHD). An estimated 43% of individuals receiving treatment for a substance use disorder (SUD) also have a diagnosis or present with symptoms of mental health disorders, and this is more pronounced with depression and anxiety.1 Unfortunately, many fail to receive adequate treatment due to the complex nature of diagnosing these two disorders.
It is important to remember that although a strong link exists between substance abuse and mental health disorders, it does not mean that one causes the other. However, the presence of one condition has been found to worsen the symptoms of the other.
Read on to learn more about the link between SUD and mental health disorders and what treatments are currently available.
Understanding substance use disorder
Substance use disorder, more commonly known as drug addiction, is a treatable mental disorder characterised by an inability to control the use of legal or illegal drugs. SUD may cause someone to continue abusing the drug despite the harm it causes.
Substances that are commonly abused include:
- Heroin, morphine, and other opioids
- Hallucinogens (drugs that alter one’s perceptions) such as LSD
Symptoms of substance use disorder
Symptoms of SUD include:
- A need to use the drug regularly
- Preoccupation with the drug, involving intense fixation that can distract you from other things (known as cravings), having intense thoughts about the drug that prevents you from having other thoughts
- Needing larger doses over time to get the same effect or ‘high’
- Putting yourself in financial difficulty to buy drugs
- Experiencing withdrawal symptoms when attempting to stop taking the drug, which can lead to relapse
Risk factors for substance use disorder
There are various risk factors for SUD, including many stressful situations and as well as psychological issues. Some of these include:
- Family history of addiction
- Pre-existing mental health illnesses
- Peer pressure
- Early use of drugs
- Absent parents
Understanding mental health disorders
Mental health disorders are characterised by a significant disturbance in an individual’s cognition, emotional regulation, or behaviour. This broad term encompasses many different disorders, which include:
- Anxiety disorders
- Affective (emotional) disorders (bipolar, depression)
- Post-traumatic stress disorder (PTSD)
- Schizophrenia (a serious mental disorder involving disconnect with reality and thoughts and psychosis)
- Eating disorders
Risk factors for mental health disorders
Although people are resilient, individuals who are exposed to certain environmental factors such as poverty, disability, violence, and trauma are at a higher risk of developing a mental health disorder.
Additionally, there is also a genetic component to the development of mental health disorders.
In most cases, mental health conditions can be managed through a combination of therapy and medications.
If you or a loved one are struggling with your mental health, it is important to seek help. The sooner you get help, the better the chance for a long-term recovery.
The link between substance use disorder and mental health disorders
Both SUD and mental health disorders are chronic brain disorders that alter how the brain functions. However, the link between them is complex.
Although drug use can begin at any point in an individual’s lifetime, for many, it begins during adolescence, and this is also a period where symptoms of mental health disorders emerge.
Some research has suggested that the presence of mental health disorders may precede the development of substance use disorder.
Common risk factors contribute to both disorders
Current research proposes three key factors that contribute to the link between SUD and mental health disorders, as listed below.2
- It is suggested that there is a strong genetic component to both SUD and other mental health illnesses; research has attributed up to 40-60% of an individual’s vulnerability to SUD to their genes.3 There are some common genes that researchers believe contribute to both mental health disorders as well as addiction.
- Furthermore, neural circuits that are commonly disrupted in psychiatric disorders may also be affected by SUD.
- Many environmental stresses are associated with the development of SUD and psychiatric disorders.
Environmental stressors include:
- Chronic stress
- Adverse childhood experiences
Mental health disorders can contribute to substance abuse
Around 1 in 4 individuals with a significant mental health condition also have SUD. People struggling with mental health conditions, such as depression, anxiety and PTSD, may use substances to self-medicate. This has resulted in specific psychiatric disorders having been established by researchers as risk factors for developing SUD.5
Despite a temporary reduction in symptoms initially, symptoms are eventually worsened over time as a result of drugs. For example, the use of cocaine over time can worsen the symptoms of bipolar disorder.4
Substance use can contribute to the development of other mental disorders
The use of substances can result in changes to the brain that are also found in other psychiatric disorders, such as depression or schizophrenia.6
It can be challenging for clinicians to accurately diagnose co-occurring disorders because the symptoms are often shared. Sometimes, one disorder remains untreated because they have similar biological, psychological and social components.
It is best to discuss the treatment options for your symptoms with a healthcare provider.
There are two main treatment options available:
- Behavioural therapies – These help to identify and rectify the disturbing behaviour pattern
Behavioural therapies are effective in treating individuals with co-occurring mental disorders and addiction. Behavioural therapy may be given alone or in combination with medications.
Examples of behavioural therapies for individuals with SUDS and co-occurring psychiatric conditions include:
- Cognitive behavioural therapy (CBT)
- Dialectical behaviour therapy (DBT)
- Assertive Community Treatment (ACT)
- Therapeutic communities
There are effective medications that are available to help with the treatment of drug addiction, including opioid, alcohol and nicotine dependency - as well as drugs available to lessen the symptoms of psychiatric disorders.
There is a strong link between substance use disorder and mental health conditions. This is because of three key factors: similar risk factors, mental health conditions contributing to SUD and SUD affecting the brain in a way which can bring about the symptoms of different mental health conditions. Unfortunately, many fail to receive adequate treatment due to the complex nature of diagnosing these two disorders.
- Goldner EM, Lusted A, Roerecke M, Rehm J, Fischer B. Prevalence of Axis-1 psychiatric (With focus on depression and anxiety) disorder and symptomatology among non-medical prescription opioid users in substance use treatment: Systematic review and meta-analyses. Addictive Behaviors [Internet]. 2014 Mar 1 [cited 2024 Jan 11];39(3):520–31. Available from: https://www.sciencedirect.com/science/article/pii/S0306460313004140
- Common comorbidities with substance use disorders research report [Internet]. Bethesda (MD): National Institutes on Drug Abuse (US); 2020 [cited 2024 Jan 15]. Available from: http://www.ncbi.nlm.nih.gov/books/NBK571451/
- Wang JC, Kapoor M, Goate AM. The genetics of substance dependence. Annu Rev Genomics Hum Genet [Internet]. 2012 Sep 22 [cited 2024 Jan 11];13:241–61. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3474605/
- Post RM, Kalivas P. Bipolar disorder and substance misuse: pathological and therapeutic implications of their comorbidity and cross-sensitisation. The British Journal of Psychiatry [Internet]. 2013 Mar [cited 2024 Jan 11];202(3):172–6. Available from: https://www.cambridge.org/core/journals/the-british-journal-of-psychiatry/article/bipolar-disorder-and-substance-misuse-pathological-and-therapeutic-implications-of-their-comorbidity-and-crosssensitisation/E738EA29B65E77C984D076BE8934CFD3
- Baigent M. Managing patients with dual diagnosis in psychiatric practice. Current Opinion in Psychiatry [Internet]. 2012 May [cited 2024 Jan 11];25(3):201–5. Available from: https://journals.lww.com/00001504-201205000-00007
- Ross S, Peselow E. Co-occurring psychotic and addictive disorders: neurobiology and diagnosis. Clinical Neuropharmacology [Internet]. 2012 Sep [cited 2024 Jan 11];35(5):235–43. Available from: https://journals.lww.com/00002826-201209000-00007