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 Table of Contents  
Year : 2016  |  Volume : 21  |  Issue : 1  |  Page : 55-57

Cannabis-induced psychosis or Cannabis-associated psychosis: Diagnostically no clear winner

Department of Psychiatry and NDDTC, All Institute of Medical Sciences, New Delhi, India

Date of Web Publication10-May-2016

Correspondence Address:
Siddharth Sarkar
Department of Psychiatry and NDDTC, Room No. 4096, 4th Floor, Teaching Block, All India Institute of Medical Sciences, Ansari Nagar, New Delhi - 110 029
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/0971-8990.182094

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Cannabis is the most commonly used illicit drug worldwide including India. The role of Cannabis in the causation of psychiatric disorders, especially psychosis remains debatable. Cannabis use has been reported to present with symptoms similar to those of schizophrenia and bipolar affective disorder. The distinction between Cannabis-induced psychoses and primary psychotic disorder is important from management perspective as it would determine the need and duration of antipsychotic medications, as well as relative focus on the management of substance use. At times, however, such a distinction may be difficult to make. We present a case where we were faced with difficulty labeling the origin of psychotic symptoms in a patient who was otherwise a heavy user of Cannabis. Management options considered in the presence of insoluble diagnostic problem have also been discussed.

Keywords: Cannabis, psychosis, schizophrenia

How to cite this article:
Rajkumar S, Balhara YP, Sarkar S. Cannabis-induced psychosis or Cannabis-associated psychosis: Diagnostically no clear winner. J Mental Health Hum Behav 2016;21:55-7

How to cite this URL:
Rajkumar S, Balhara YP, Sarkar S. Cannabis-induced psychosis or Cannabis-associated psychosis: Diagnostically no clear winner. J Mental Health Hum Behav [serial online] 2016 [cited 2022 Dec 2];21:55-7. Available from: https://www.jmhhb.org/text.asp?2016/21/1/55/182094

  Introduction Top

The association between Cannabis and psychotic symptoms is well documented.[1] However, the relationship of Cannabis use with psychotic symptoms may be either causal (as in Cannabis-induced psychosis) or just associational, explained by other factors (as in occurrence of Cannabis use disorder and schizophrenia together). The distinction between causality and association (noncausal) has management implications in patients with psychosis and Cannabis use. While cessation of Cannabis use is expected to improve the psychotic symptoms in Cannabis-induced psychosis, such spontaneous resolution of symptoms might not occur in patients with schizophrenia and Cannabis use. The teasing out of diagnosis between the two entities as mentioned above might be far from easy in the clinical setting. We present a case that posed considerable difficulty in the correct application of the diagnostic label, particularly with regard to the genesis of psychotic symptoms in an individual who had been using Cannabis in the background of other substances.

  Case Report Top

Mr. HK, a 28-year-old unmarried electrician, who had a history of tobacco use for 20 years and Cannabis use for 18 years, was brought to us with a 4 months history of behavioral aberrations. He started using tobacco in the form of beedies at the age of 8 years and progressed to its dependent use. He also started the use of Cannabis in the form of ganja at the age of 10 years that was introduced to him by his friends. He reported feeling happy and able to play or work for prolonged periods without fatigue after taking ganja filled in beedies and also rolled in paper. He initially smoked ganja about 1–2 times/week, but over time gradually progressed to daily use of ganja. He shifted to smoking ganja in chillum (pipe) after he saw other elder substance users take ganja in this manner. He reported a greater kick after taking ganja in chillum than in beedies. Patient's academic performance had deteriorated over time and he would while away his time. His parents came to know about his substance use from others in the neighborhood. However, he continued ganja use in spite of repeated advice and requests of his parents as he felt quite happy after taking ganja.

The patient would visit temples, help with cleaning work there, and also smoke ganja available there with sadhus (3–4 chillums per day). On days he would not be able to smoke, he reports his mind would be restless and he will not be able to focus. He dropped out of school not able to pass the 10th standard because of deteriorating academic performance. He took up the job of an apprentice with an electrician but continued Cannabis and tobacco use. He would be able to work fearlessly at heights under influence of Cannabis where others would be afraid to work. He denies history suggestive of auditory hallucinations, made phenomenon, and thought phenomenon at this time.

He says that started chasing heroin (“smack”) at around 24 years of age. He would feel calm and less fatigued after the use of heroin and gradually would require greater amounts to get the same high. He would develop withdrawal symptoms while stopping heroin in the form of body ache, lacrimation, and rhinorrhea and would have an intense desire to continue taking this substance. In case heroin was not available, he would substitute it with codeine-containing cough syrups or dextropropoxyphene. His Cannabis use continued in the form of ganja or charas during this time. Despite the use of substances, his sleep, appetite, and self-care were adequate and he kept on working and performed adequately.

About 4 months before contact at our center, his family members found him roaming around in a nearby town and he was brought back home. He had gone away from home after the contract of his work had finished about 7 months before contact at our center and had apparently gone to temples and continued smoking ganja there. He could not explain how he reached the place but recognized the family members. While at home, he had difficulty falling asleep and would be seen pacing even at midnight. He would speak more than usual and have an irritable affect. He would claim that he himself was god which he continued to believe even after repeated criticism and confrontation by family members. At specific spots near home at dusk, he would report instances of hearing voices of children screaming when there was no one around. The voices would be as clear as any other voice, emanating from a distance of 1–2 m, heard through his ears, lasting for 2–5 min at one instance, and heard once or twice per day. He would search around but would find no one. His family members would not hear these voices.

The patient would believe to be in control of everything around him. On one instance when he saw an airplane flying high in the sky, he fixed his gaze over it with an aim to bring it down and was confident that he shall be able to do so. He would also report that when he travelled around, girls would get sexually attracted to him, and he would come to know from their gestures such as hand movements and gaze. When he communicated these events to friends and family, they dismissed the events as rubbish. He firmly believed he was Shani Dev, the god for whom prayers are offered on Saturdays. His belief was based on the reason that since patient himself and Shani Dev both used supari; he had become Shani Dev despite friends and family members rejected this. On one rainy day, he was very upset as it reminded him of purpose in life to bring Shiva back to Haryana (his native place). Shiva, as per the patient is presently located in Mecca, where people go during Hajj pilgrimage. He wanted to bring Shiva from Mecca as he felt rain was the indication of Shiva bleeding due to the stones being pelted on him. This belief would not be shared by his family members, and the patient did not provide any reason for how rain is an indication for Shiva bleeding.

He firmly believed his thoughts were known to other people. His thoughts would escape his brain via invisible waves emanating from his forehead and both ears and be transmitted the same instant he thinks and people around would come to know. He would learn by experience that he could stop these waves by tying a towel over his forehead that would cover his ears too.

The family members report that during the past 4 months he was more irritable than his previous self and more authoritative on instances. He would collect waste papers and empty talcum powder bottle and keep with him. He would also bring damaged and abandoned idols of Gods lying on the street to home, clean it, do pooja and completely damage it after some time without any reason. His sleep would be less than his usual self, and his appetite was slightly reduced. His personal care was poor and he would have to be coerced to take bath. He would get into altercation with family members with minimal or no provocation while demanding money to buy Cannabis. Due to the oddities in behavior and speech, the family members would try to keep him at home but he would not stay. He would continue to use beedies and ganja even during this time though his opioid use had declined. He reported that smoking ganja in the past few months helped him stay to himself and free from the chaos around him and plan regarding his future with no effect on other symptoms patient was experiencing. He failed to recall any increase in the use of ganja just before the behavioral disturbances in recent past.

The patient was brought to our center and admitted due to difficulty in managing him at home. On evaluation, past medical and family history were noncontributory. On mental status examination, the patient was found to be authoritative, and his thought sample revealed delusion of special mission, grandiose delusion of being god and thought broadcast. His personal and social judgment was impaired and insight was absent. At admission, urine screen for drug use was done which was positive for Cannabis and benzodiazepines. His brief psychiatric rating scale score was 43 and mini mental status examination score was 29/30. The patient was started on olanzapine (10 mg/day) with nicotine gum and diazepam. A diagnosis of Cannabis dependence syndrome currently abstinent in a protected environment (F12.21), tobacco dependence syndrome currently on a clinically supervised or replacement regime (F17.22), and opioid dependence syndrome currently abstinent (F11.20) were made. A differential diagnosis of Cannabis-induced psychotic disorder, schizophrenia-like (F12.50) and schizophrenia, paranoid subtype (F20.0) was considered; the points in favor of each are highlighted in [Table 1].
Table 1: Diagnostic clarification

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  Discussion Top

The present case throws up a diagnostic challenge for patients with Cannabis use who subsequently go on to develop psychotic symptoms. Though the treating team could not be definitive about the diagnosis with the initial assessment, the condition of the patient required initiation of antipsychotics for management of the manifest behavioral problems and agitation. Improvement was observed in the psychotic symptoms, and the patient was subsequently discharged. The treatment team is still faced with the challenge of whether and when to taper off antipsychotics. Given the long-term substance use and possible high risk of relapse, it was decided that the best course of action would be to continue the antipsychotic treatment and provide the treatment on the lines of first episode psychosis.

The effect of Cannabis and its role in psychosis has been a topic of interest for a long time.[2] Individuals with schizophrenia have a higher prevalence of Cannabis use than the general population.[3] Although Cannabis has been reported to be a vulnerability factor for genesis of schizophrenia and cannabinoids have been reported to have psychotomimetic effects, Cannabis use has also been reported as a means of self-medicating negative affect in patients experiencing prodromal or clear psychotic symptoms.[4]

In the current patient, the age at exposure to Cannabis was 10 years and his habit size was large considering the regular use at increasing quantities until presentation. This is consistent with the study findings that earlier the age of exposure, particularly in adolescence, greater is the risk of developing psychosis. One study concluded that the early age can be a risk only if Cannabis use began by age 14.[5] Another study found that the average duration between exposure to Cannabis and incidence of first episode psychosis was 7–8 years and brain of individuals aged 12–19 years were continually sensitive to Cannabis.[6] Hence, the role of Cannabis in genesis of psychotic symptoms in the current patient seems to be in line with the existent literature. Various studies have suggested that higher the concentration of cannabinoids, greater the incidence of psychotic symptoms.[7],[8] Although this patient's habit size increased, the quality of Cannabis he was using and the content of cannabinoids in it were not known.

It is also important to pay close attention to the symptom profile of patients with substance-induced psychosis as studies have shown that Cannabis-induced psychosis usually presents with psychomotor agitation, increased verbal output, irritable affect, the presence of delusions and hallucinations.[9] The current patient presented with delusions, auditory hallucinations, and irritable affect. However, the presence of thought broadcast being a rather core schizophrenic symptom suggested a diagnosis of schizophrenia in this case.[10] It must be reckoned that substance-induced psychotic disorder might not be a very stable diagnosis and conversion rates approaching fifty percent have been reported for this diagnosis.[11]

At present, there are no clear management guidelines for substance-induced psychosis in comparison to independent psychotic disorder. The decision for the management, with or without medications, would need to take into consideration the severity of psychotic symptoms, the certainty of the diagnosis and likelihood of consistently abstaining from substances of use. Since both substance use disorders and psychotic disorders are often chronic relapsing conditions, due diligence is required for close monitoring and follow-up of such patients.

Financial support and sponsorship


Conflicts of interest

There are no conflicts of interest.

  References Top

Radhakrishnan R, Wilkinson ST, D'Souza DC. Gone to pot – A review of the association between Cannabis and psychosis. Front Psychiatry 2014;5:54.  Back to cited text no. 1
Ames F. A clinical and metabolic study of acute intoxication with Cannabis sativa and its role in the model psychoses. J Ment Sci 1958;104:972-99.  Back to cited text no. 2
Morgan VA, Waterreus A, Jablensky A, Mackinnon A, McGrath JJ, Carr V, et al. People living with psychotic illness in 2010: The second Australian national survey of psychosis. Aust N Z J Psychiatry 2012;46:735-52.  Back to cited text no. 3
Henquet C, van Os J, Kuepper R, Delespaul P, Smits M, Campo JA, et al. Psychosis reactivity to Cannabis use in daily life: An experience sampling study. Br J Psychiatry 2010;196:447-53.  Back to cited text no. 4
Schimmelmann BG, Conus P, Cotton SM, Kupferschmid S, Karow A, Schultze-Lutter F, et al. Cannabis use disorder and age at onset of psychosis – A study in first-episode patients. Schizophr Res 2011;129:52-6.  Back to cited text no. 5
Stefanis NC, Dragovic M, Power BD, Jablensky A, Castle D, Morgan VA. Age at initiation of Cannabis use predicts age at onset of psychosis: The 7- to 8-year trend. Schizophr Bull 2013;39:251-4.  Back to cited text no. 6
Moore TH, Zammit S, Lingford-Hughes A, Barnes TR, Jones PB, Burke M, et al. Cannabis use and risk of psychotic or affective mental health outcomes: A systematic review. Lancet 2007;370:319-28.  Back to cited text no. 7
Torjesen I. High potency Cannabis is associated with tripled risk of psychosis, study indicates. BMJ 2015;350:h939.  Back to cited text no. 8
Aggarwal M, Banerjee A, Singh SM, Mattoo SK, Basu D. Substance-induced psychotic disorders: 13-year data from a de-addiction centre and their clinical implications. Asian J Psychiatr 2012;5:220-4.  Back to cited text no. 9
Zhornitsky S, Tikàsz A, Rizkallah É, Chiasson JP, Potvin S. Psychopathology in substance use disorder patients with and without substance-induced psychosis. J Addict 2015;2015:843762.  Back to cited text no. 10
Kirkbride J. The risk of substance-induced psychosis converting to schizophrenia varies with substance used and patient age. Evid Based Ment Health 2013;16:65.  Back to cited text no. 11


  [Table 1]


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