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Page clinically reviewed by Dr William Shanahan, Medical Director and Clinical Director of Addictions, at Priory Hospital Roehampton in October 2022.

What is Drug Induced Psychosis?

Psychosis is a mental health problem which temporarily causes someone to interpret the world differently from those around them. Drug-induced psychosis happens when you experience episodes of psychosis, such as delusions or hallucinations, as a direct result of substance abuse. This can either exacerbate or trigger the onset of mental illnesses such as bipolar disorder and schizophrenia, which can be characterised by symptoms of psychosis, due to being predisposed to the condition.

Drug-induced psychosis is often caused by taking too much of a certain drug, so that its level of toxicity provokes paranoia and a psychotic episode. It can also occur if you have an adverse reaction from mixing different substances, or withdrawing from a drug, prescribed or otherwise.

Psychosis is often characterised by delusions or hallucinations, which are experiences that are far removed from reality. Delusions are irrational beliefs that a person holds, even when they are presented with evidence that contradicts these beliefs. Hallucinations refer to intense sensory perceptions of phenomena that are not real, and are characterised by individuals vividly feeling, seeing, smelling, or hearing things that do not truly exist.

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Symptoms of Drug Induced Psychosis

The symptoms of drug-induced psychosis are often gradual, with toxicity of the drug becoming more dangerous as the frequency and dosage of the drug increases with dependency. If you have an underlying mental health condition, then use of psychoactive drugs will likely worsen your symptoms, result in extreme paranoia, and can speed up the onset of psychotic disorders such as bipolar disorder and schizophrenia. Extensive use of drugs and alcohol can also cause symptoms of psychosis to occur even if you aren’t diagnosed with co-occurring mental illness.

Some of the symptoms of drug induced psychosis include:

  • Paranoia
  • Delusions
  • Auditory and visual hallucinations
  • Olfactory (smell) hallucinations
  • Anti-social behaviour
  • Panic attacks
  • Confusion

Symptoms of Delusion

Delusions are when you may believe that something is happening that isn’t reflective of the real world, and you may ignore any challenges to these beliefs from others, as to you, it will feel like a real scenario.

Delusions take on various forms, including:

  • Persecution delusions - where you might believe someone is spying on you
  • Jealousy delusions - often involving a partner, where you may believe they have been unfaithful, although there is no evidence for this
  • Grandiose delusions - where you may experience an exaggerated sense of power, such as believing that you have magical abilities or you have made a major discovery  

Hallucination Symptoms

Hallucinations are distorted sensory perceptions of what is happening around you. They usually involve visual or auditory changes but can also relate to smell and touch.

Hallucinations take on various forms, including:

  • Auditory hallucinations - involving hearing voices, such as a voice narrating your movements or actions, or two separate voices arguing between each other
  • Visual hallucinations - occurring when you see a different reality to that of others, with shadows, objects and people viewed that aren’t really there, and can be particularly distressing
  • Olfactory hallucinations - some might think that they are emitting strange odours or are rotting inside. The fear is compounded by a belief that other people can smell it as well

What Drugs can send you into Psychosis?

The drugs that are often reported in cases of drug-induced psychosis, and are most likely to result in psychotic symptoms, include cannabis, cocaine, amphetamines, methamphetamine, psychedelic drugs such as LSD, and club drugs such as ecstasy and MDMA. Symptoms of psychosis can vary depending on which drugs have been taken and the quantity that has been taken, but heavy and excessive use can result in prolonged symptoms.

Drugs such as cocaine, cannabis and hallucinogens can also worsen symptoms of existing mental illnesses. Taking substances like cannabis for a long period of time can also see you develop symptoms of psychosis, including paranoia, as in high doses, THCs can induce temporary schizophrenia-like psychotic symptoms such as paranoia, delusions, anxiety and hallucinations, as well as present other symptoms of a cannabis addiction

Drug-induced psychosis relating to prescription medication usually occurs when individuals are not taking the drug at the recommended dose or continuing to use the drug beyond the advised period of time, with drugs such as ketamine mimicking psychosis in the form of delusions and disordered thinking when abused.

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Cannabis Use Linked to Rise in Psychosis

According to Priory expert Dr Niall Campbell, cannabis misuse is on the rise, especially amongst teens, and it is strongly linked to increasing drug induced psychosis cases. 

“I am seeing an increasing number of young adults with paranoid psychoses – a schizophrenia-like illness and depression, which developed from marijuana use,” he said.

Read more about how cannabis and psychosis are linked.

Drug Induced Psychosis Recovery

If you are diagnosed with drug-induced psychosis, it will often be part of a co-morbidity or a diagnosis of substance addiction and an underlying mental illness, which will need to be treated as separate issues to aid effective recovery or reduction of symptoms. This means that you will undergo a medically assisted detoxification programme in order to become medically stable and manage drug withdrawal symptoms, before beginning an individual treatment plan for any underlying mental health issues which may have contributed to the onset of psychosis symptoms.

While removal of the drug from your system may remove symptoms of psychosis, if you have an underlying mental health condition such as anxiety or depression which prompted excessive use of a drug, or you have been diagnosed with an existing psychotic disorder such as bipolar disorder or schizophrenia, further treatment will be required to address these conditions and aid recovery.

If psychosis has been triggered through drug use in order to cope with underlying mental illness, a diagnosis will need to determine whether symptoms would continue without the drug present, as this would not be drug-related psychosis. Drug-induced psychosis is more apparent when your symptoms wear off after you have stopped using the drug, while the initial symptoms such as social withdrawal and lack of motivation may gradually build to include delusions and hallucinations.

If the underlying mental health condition features psychotic episodes as a symptom, then antidepressant, anti-psychotic or other medications such as clozapine (Clozaril) may be recommended for an extended period of time, particularly if delusions and hallucinations are frequent or particularly severe.

Drug Induced Psychosis Treatment

When treating drug-induced psychosis, the first step towards recovery must include termination of use of the drug that initially caused the episode. The medically assisted detoxification programme at Priory will ensure that you have no further interaction with drugs that could be habit forming or that could interfere with the drug being abused, with carefully selected drugs helping with symptoms of withdrawal only.  

Once you have been medically stabilised, the practical and problem-solving talking therapy, cognitive behavioural therapy (CBT), can help you to learn more about the thoughts and moods that you experience before psychotic episodes occur, helping you to manage your emotions and paranoia more readily, and be aware of triggers. Due to the serious nature of drug-induced psychosis and associated psychotic conditions, family therapy involving those closest to you, may also be used to treat drug psychosis, ensuring that there is sufficient support available at home to prevent relapse and manage associated symptoms, potentially reducing the need for extensive hospital treatment.

Priory’s experienced therapists and consultants are trained in treating drug-induced psychosis, and can offer you a safe and understanding treatment environment as part of a bespoke treatment plan, which is aimed at reducing associated symptoms of psychosis and drug addiction, before targeting any underlying health issues which may have been triggered by substance abuse.

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