can psychoactive substances cause poor mental health? 

Psychoactive substance use can increase the risk of developing mental health problems and worsen existing conditions.

Increased risk of mental health problems
Individuals who use substances are more likely to experience self-harm and suicidal thoughts. Substance use can contribute to impulsive behaviours and feelings of hopelessness, which may increase the chances of self-injury or suicide attempts. People experiencing poor mental health are more likely to use substances to self-medicate as a means of coping with distress, hence creating a negative feedback loop.  

Long-term mental health consequences
In some cases, using recreational drugs can lead to the development of long-lasting mental health problems. For example: 

• Certain substances may trigger or worsen depression:  

There is evidence that some cases of depression are substance-induced – meaning they are directly caused by the effects of alcohol or drugs. In many cases, these symptoms may improve or resolve once the substance use is reduced or stopped, but only when controlled. 

• Some drugs, particularly stimulants and hallucinogens, can induce psychosis, a severe condition characterised by losing touch with reality.

 People may temporarily lose touch with reality. For example, this can include experiencing hallucinations (like hearing voices) or delusions (false, often paranoid beliefs) due to substance-induced psychosis. 

This can happen during intoxication or withdrawal from substances like amphetamine, cocaine, cannabis or LSD. For example, high doses of amphetamines can cause intense paranoia and agitation that closely resembles symptoms of schizophrenia.  

While symptoms often improve after the drug wears off, repeated use or high doses can cause longer-lasting effects, especially in vulnerable people who might have a personal or family history of poor mental health.   

• There is also evidence linking drug use with increased risk for conditions like schizophrenia:

Adolescent cannabis use is a significant risk factor for psychosis. People who use a lot of cannabis are almost four times more likely to develop schizophrenia or other psychosis-related mental health problems compared to people who don’t use it at all.  

However, it can be more complicated. Research shows that adolescents who later develop schizophrenia are more likely to pick up cannabis in the first place (for example, to self-medicate), resulting in a bi-directional relationship between cannabis use and schizophrenia risk.  

Substance Use Disorder (SUD)

Substance Use Disorder (SUD) is a complex condition where a person continues using a substance despite harmful consequences. It’s often called an addiction. People with SUD develop an intense focus on using substances – such as alcohol, tobacco or other drugs – that interferes with their daily life, relationships and wellbeing. 

How do I know if I am using substances? 

Recognising substance use can be challenging, especially if you are using substances to cope with mental health issues. Here are some signs that you may be using substances: 

Increased tolerance: Needing more of the substance to achieve the same effect.

Withdrawal symptoms: Experiencing physical or psychological symptoms when not using the substance. These can include sleeping problems, nausea, sweating, dissociation, shaking or sensory disturbances.

Neglecting responsibilities: Failing to fulfil obligations at work, school or home due to substance use.

Loss of control: Consuming more of the substance than intended or being unable to cut down despite wanting to.

Social problems: Facing issues in relationships or social activities because of substance use.

Addiction: Feeling a persistent desire or craving for the substance, spending a significant amount of time obtaining, using or recovering from its effects.

How to support yourself with substance use

If you are struggling with both substance use and mental health issues, it is essential to take proactive steps towards recovery: 

• Seek professional help: Contact a healthcare provider to discuss your symptoms and receive a proper diagnosis. In Scotland, integrated treatment programmes that address both mental health and substance use simultaneously are highly recommended. You can read more about this on the NHS inform website. 
• Practise self-care: Engage in activities that promote physical and mental wellbeing, such as regular exercise, a healthy diet and sufficient sleep. Mindfulness practices like meditation or yoga and learning grounding techniques can also be beneficial. 
• Build a support network: Surround yourself with supportive friends and family who understand your struggles and can offer encouragement. Try to integrate with different social circles that might not revolve around substance use. Support groups specifically for substance use and mental health like those listed at the bottom of this page can provide additional communal support. 

How to help others 

Supporting someone with co-occurring substance use and mental health issues requires empathy, patience and understanding:

Gain a deeper understanding

Learn about their conditions to better understand what they are going through and how you can help.

Offer non-judgmental support

Listen to them without judgement and offer a safe space for them to express their feelings. Avoid giving unsolicited advice and instead offer to help them in finding professional support.

Encourage treatment

Recommend that they seek professional help and support them in attending appointments or following treatment plans. Be patient and understand that recovery is a process that takes time.