Mental Health and Substance Misuse: Why Are They Linked?

In short: Mental health problems and substance misuse often occur together, and the link runs in both directions. Some people use alcohol or drugs to ease distressing symptoms, while substance use can also trigger or worsen conditions such as anxiety, depression and psychosis. Shared risk factors, including trauma, genetics and social circumstances, contribute to both. When the two occur together (often called "dual diagnosis" or co-occurring conditions), the best outcomes come from support that addresses both at the same time.

This guide, written by a Ready Health prescribing pharmacist, explains why mental health problems and substance misuse are connected and where to find help in the UK.

How common is it to have both a mental health problem and substance misuse?

Co-occurring mental health and substance use problems are common, particularly among people with severe mental illness and among people in contact with drug and alcohol services. NICE guidance (NG58) recognises that people in this situation are often poorly served when services treat each problem separately, and recommends that care is coordinated around the person.

Why might someone with a mental health problem use drugs or alcohol?

To relieve symptoms (the self-medication idea)

Some people use substances to dampen symptoms or side effects. Examples include drinking to quieten anxiety, using stimulants to lift low mood or energy, or using nicotine or caffeine to counter the drowsiness some medicines can cause. Research shows this pattern is not consistent, though: people do not always choose a substance that matches their symptoms, and some cut down when they are unwell.

To cope with difficult feelings or experiences

Alcohol and drugs can offer short-term relief from stress, boredom, loneliness, painful memories or social anxiety. Over time, this way of coping tends to backfire: tolerance develops, withdrawal adds to distress, and the original symptoms often worsen.

Social factors and a sense of belonging

People living with mental illness can face isolation, unemployment, housing problems and stigma. Social groups where substance use is normal may offer acceptance and connection, which can make it harder to cut down even when harm is clear.

Can substance use cause mental health problems?

Yes. The relationship is two-way. For example:

• Cannabis: regular use, especially of high-strength forms and from a young age, is linked with an increased risk of psychosis and can worsen existing psychotic illness.
• Alcohol: heavy drinking is associated with depression, anxiety and increased risk of self-harm.
• Stimulants such as cocaine and amphetamines can cause anxiety, paranoia and, in some cases, psychosis.
• Withdrawal from alcohol, benzodiazepines and some other drugs can cause severe anxiety, low mood and sleep problems.

Are there shared causes behind both?

Often. Factors that increase the risk of both mental health conditions and substance misuse include:

• genetic and family factors, such as growing up with a parent who misuses substances;
• adverse childhood experiences and trauma, including abuse and neglect;
• chronic stress, poverty and social exclusion;
• untreated conditions such as ADHD, where impulsivity and difficulties with emotional regulation can increase risk.

What does good support for dual diagnosis look like?

Nobody should be refused mental health care solely because they use substances, and nobody should be refused substance use treatment solely because they have a mental health condition.

Where can I get help in the UK?

• Your GP, who can assess you and refer you to local mental health or drug and alcohol services.
• Local drug and alcohol services, many of which accept self-referrals.
• Talk to FRANK (0300 123 6600) for confidential drug information and advice.
• NHS 111 (select the mental health option) or Samaritans (116 123) if you are struggling.
• Call 999 or go to A&E in an emergency, including if you have taken an overdose or have thoughts of ending your life.

Do not stop alcohol or benzodiazepines suddenly if you are dependent, as withdrawal can be dangerous. Seek medical advice first.

Frequently asked questions

What is a dual diagnosis?

It describes a person who has both a mental health condition and a problem with alcohol or drug use at the same time.

Which comes first, the mental health problem or the substance use?

It varies. Either can come first, they can develop together, or both can stem from shared causes such as trauma.

Will I be judged if I tell a clinician about my drug or alcohol use?

Clinicians should respond without judgement. Being open helps them treat you safely, including checking for interactions with any medicines.

Can treating my mental health reduce my substance use?

For some people, yes, particularly when substance use is a way of coping with symptoms. Most people benefit from support that addresses both.

Key takeaways

• Mental health problems and substance misuse frequently occur together and influence each other.
• Self-medication, coping and social factors can all play a part, alongside shared risks such as trauma.
• Substances such as cannabis, alcohol and stimulants can trigger or worsen mental health symptoms.
• Coordinated, non-judgemental care that addresses both problems gives the best chance of recovery.

Sources and further reading

• NICE NG58: Coexisting severe mental illness and substance misuse
• NHS: Addiction support
• Talk to FRANK
• Mind: Recreational drugs, alcohol and addiction

Last reviewed: October 2026 by Shamir Patel, Independent Prescribing Pharmacist, Ready Health. This article is general information and does not replace advice from your own clinician.

If you would like confidential support with your mental health in Standish, Wigan, book a consultation with Ready Health. Our clinicians can talk through your situation and help you find the right next steps.