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Can Substance Abuse Cause Psychosis?

  • Psychosis is a mental health problem which temporarily makes the person affected interpret the world differently from those around them.1 It is considered a symptom, whether it comes from a severe mental illness, a physical illness or from using a psychoactive substance.2
  • Psychotic episodes may include hearing or seeing things which are not actually there (hallucinations), false beliefs which may seem irrational to others (delusions) and other abnormal experiences, due to mental dysfunction, such as memory and sleep problems, lack of attention and incoherent speech.3

In this section

What is Substance-Induced Psychosis?

Substance-induced psychosis can happen as a result of excessively using various psychoactive substances, such as cannabis, alcohol, hallucinogens and cocaine4. Misuse of those drugs may produce psychotic reactions similar to those experienced in schizophrenia.5

The use of such substances has dramatically increased, particularly during early adolescence, when the brain is still developing and can be especially sensitive to environmental exposures.5 Several studies have shown that drug intoxication can initially produce temporary, mild effects, that may worsen with time.5-7

Almost any type of intoxicating substances can cause psychosis, although the specifics of the symptoms tend to vary, based on the drug consumed. Psychotic symptoms may recede upon substance withdrawal, or they may persist for an indefinite period of time, while developing withdrawal symptoms is also possible.8

Some of the most common forms of drug-induced psychosis include:

1.     Cannabis-induced psychosis.
While psychotic episodes following cannabis intake are rare, some users may experience a cascade of delusions and hallucinations, along with feelings of paranoia and anxiety.9 The symptoms are generally short-lived and total remission can be expected.9
2.    Methamphetamine (METH)-induced psychosis.
Research has shown that METH psychosis is a prevalent health concern among recreational users.9 Frequent abusers of methamphetamine can lapse into frightening hallucinatory and delusional states that may last for weeks even when the drug is no longer being used.10 Recreational METH users are two to three times more likely to experience psychotic symptoms than non-users, especially if they started METH at young age.10,11
3.     Cocaine-induced psychosis.
Cocaine consumption can induce transient psychotic symptoms, expressed as paranoia or hallucinations.12 Up to half of all regular cocaine users may experience at least some psychotic episodes.12 Severe cocaine-induced psychosis may be marked by hostility, aggressiveness, and extreme paranoia.12
4.    Ecstasy-induced psychosis.
Ecstasy and other analogous substances have neurotoxic properties and can trigger psychosis.13 Most of the symptoms are positive, but negative symptoms are also present.13

Who is At Risk of Experiencing Substance-Induced Psychosis?

Drug-induced psychotic disorder is primarily related to substance abuse rather than substance consumption.14 In most cases people who experience these symptoms are either addicted to these substances or have been using them in unusually heavy amounts.12
The prevalence of psychotic episodes relates to:

Genetic abnormalities or family history of mental illness.15 Previous history of mental health disorders and/or psychiatric hospitalisation in the family, are widely accepted as the major risk factors for such episodes.15 Other factors, such as variation by place of birth and upbringing, migration history and minority status continue to court controversy, despite an increasingly robust empirical base.16,17 There is evidence that urban settings are associated with higher rates of psychotic symptoms18.  Selective migration to western countries may also contribute to a higher prevalence of psychosis.19 The association between migrant status and increased risk of psychosis has stimulated a great deal of research; the results from different studies around migration status point to the same direction, there is a higher prevalence of psychosis among minority ethnic groups compared with white population.18-20

Gender and age.18,20 Most studies claim that men and women have the same tendency to be affected. Psychotic episodes are more likely to be experienced by men at a younger age compared to women, but the association is still unclear. A systematic review in England indicated that the first psychotic experience appears at a younger age in men, often in their teens and early 20s, than in women.20 The exact mechanism has not been identified.21

Vulnerability. Several studies concluded to the hypothesis that, there is a shared genetic aetiology between cannabis use and schizophrenia, and schizophrenia risk increases the risk of cannabis use.31,32 Also, patients with schizophrenia or schizophrenia-like disorders have an increased vulnerability to compulsive use of drugs.22,23 Another explanation of the increased incidence of substance-abuse among patients with schizophrenia is the self-medication hypothesis. Narcotics are primarily used in order to deal with the negative symptoms of the disease, as well as drug use, in an attempt to decrease discomfort from the side effects of antipsychotic medication.23

Can Substance Abuse Cause Schizophrenia?

There is evidence that substance-induced psychosis is associated with the later development of schizophrenia.24
Substance abuse does not cause schizophrenia, but it can act as an environmental trigger.25 Using drugs such as cocaine, amphetamines and cannabis can increase the risk for or even induce schizophrenic symptoms and/or worsen their severity.26

As mentioned above, people with psychotic disorders choose ‘’self-medication’’ and use alcohol or other drugs to help them cope with their symptoms of psychosis.21,22  While this may provide some short-term relief from symptoms, alcohol and other drug use can make a person’s existing symptoms worse. In addition, some people find that they develop alcohol or other drug problems because they use greater amounts more frequently to cope with their psychosis. As a result, a cycle is generated where psychosis symptoms and substance abuse feed off each other (Figure 1).27

Cycle of psychosis symptoms, cravings, and drug useCycle of psychosis symptoms, cravings, and drug use

Cycle of psychosis symptoms, cravings, and drug use

What Treatment Should Be Offered?

The main focus of treatment for these patients focuses on stabilisation of psychotic symptoms, hostility, and agitation.23
Several new antipsychotic medications have been introduced and appear to be safer and more effective than typical antipsychotics.28 In the early stages of recovery, people may transition from medical detox for the safe management of drug withdrawal to psychiatric hospitalisation.29 Addiction and mental health clinics host inpatient treatment programmes to help the patient to achieve a more stable state of mind, while removing the influence of the illicit substances that provoked the disturbing outbreak of psychotic symptoms.26

After this programme is complete, the person affected by substance-induced psychosis will move on to outpatient treatment and aftercare.28 Complementary treatment methods, like holistic mind-body practices and life skills training, may also be offered based on the needs of each individual patient.30
Overall, substance-induced psychosis is a sign of serious mental health disturbance. But with expert support and intensive continuing care, people can overcome the worst of their symptoms and regain their ability to manage their own lives.


  1. [accessed on the 17th of October 2019]
  2.—for-young-people [accessed on the 17th of October 2019]
  3. Wolfgang and Jürgen. Dialogues Clin Neurosci. 2015; 17(1): 9–18
  4. [accessed on the 17th of October 2019]
  5. Mauri. Dual Diagn Open Acc 2016; 1:11.
  6. Forti et al. Lancet Psychiatry 2015; 2: 233–238
  7. Fattore. Biol Psychiatry 2016; 79: 539–548
  8. Hang et al. Medicine (Baltimore) 2017; 96(15): e6434.
  9. Arendt et al. BJP 2005, 187:510-515.
  10. McKetin et al. Drug Alcohol Rev. 2010; 29:358–63.
  11. Chen et al. Psychol Med. 2003; 33:1407–14.
  12. Roncero et al. Eur Psychiatry. 2013;28(3):141-6.
  13. Landabaso et al. Eur Addict Res 2002;8:133–140
  14. Bramness et al. BMC Psychiatry. 2012; 12: 221.
  15. O’Donovan et al. Nat Genet. 2008; 40(9):1053-5.
  16. Coid et al. Arch Gen Psychiatry. 2008; 65(11):1250-8.
  17. March et al. Epidemiol Rev. 2008; 30:84-100.
  18. Cheng et al. Psychological Medicine. 2011;41:949–958.
  19. Selten et al. Br J Psychiatry. 2001; 178():367-72.
  20. Kirkbide et al. PLoS One. 2012; 7(3): e31660.
  21. Ringen et al. Acta Psychiatr Scand. 2008; 118(4):297-304.
  22. Ringen et al. Psychol Med. 2008 Sep; 38(9):1241-9.
  23. Winklbaur et al. Dialogues Clin Neurosci. 2006; 8(1): 37–43.
  24. Schoeler et al. Lancet Psychiatry 2016; 3: 215–225.
  25. [accessed on the 17th of October 2019]
  26. [accessed on the 17th of October 2019]
  27. [accessed on the 17th of October 2019]
  28. Starzer et al. Am J Psychiatry. 2018; 175(4):343-350.
  29. Green J Subst Abuse Treat. 2008 Jan; 34(1):61-71
  30. Dickey et al. J Ment Health Policy Econ. 2000;3:27–33.
  31. Power RA, Verweij KJ, Zuhair M, Montgomery GW, Henders AK, Heath AC, Madden PA, Medland SE, Wray NR, Martin NG, Mol Psychiatry. 2014 Nov; 19(11):1201-4.
  32. Psychol Med. 2017 Apr; 47(5):971-980. doi: 10.1017/S0033291716003172. Epub 2016 Dec 8. Assessing causality in associations between cannabis use and schizophrenia risk: a two-sample Mendelian randomization study. Gage SH1, Jones HJ1, Burgess S2, Bowden J1, Davey Smith G1, Zammit S3, Munafò MR1
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Studies show that people with schizophrenia may be at high risk of attempting suicide. In particular, symptoms of depression, active hallucinations and delusion

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Schizophrenia is a severe neuropsychiatric disorder with heterogeneous clinical outcomes. It affects people differently, as the symptoms can vary from person to

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