Influence of variables of cannabis abuse on psychotic symptoms and their severity: an Indian experience

Abstract:

Context: Cannabis is probably the most commonly used illicit drug. While not all cannabis users present mental health problems, heavy cannabis use may increase the risk of cognitive abnormalities, psychotic illness, and mood disorders. Cannabis-induced psychosis is not easily distinguishable from schizophrenic symptomatology, although it is characterized by more bizarre behaviour, violence, panic, more agitation, and less blunting of affect, and incoherent speech.

Aims: To evaluate severity of various psychotic symptoms in relation to variables of cannabis abuse.

Settings and Design: A cross sectional study of 30 male patients admitted at tertiary psychiatric centre, with diagnosis of cannabis induced psychosis was carried out.

Methods and Material: Cannabis abuse variables along with psychotic symptoms severity on BPRS scale was obtained.

Statistical analysis used: SPSS-17 was used for analysis, and significance level was at p-value <0.05. Correlation between variables of cannabis abuse and psychotic symptoms and total BPRS score were derived using Pearson correlation 2- tailed test.

Results: The symptoms that were associated with increased severity in majority of patients were hostility (83%), excitement (77%), and elevated mood, grandiosity, suspiciousness and motor hyperactivity were preset in more than 60% of individuals in range of severe to very severe form.

Conclusions: Patients with long duration and early onset of cannabis abuse were presented with more severe form of psychosis. Frequency of cannabis use was not significantly correlated with total BPRS score, although amount spent over cannabis was significantly associated with total BPRS score. Family history of cannabis abuse predicted early onset of cannabis abuse.

Introduction

Cannabis is probably most commonly used illicit drug. ^[1,2] It is widely used in India and is an integral part of Indian culture and religious customs.^[3,4] The correlation between cannabis and negative mental health outcomes has been unequivocally established ^[1,5,6,7,12]. While not all cannabis users present mental health problems, ^[5] epidemiological studies suggest that heavy cannabis use during adolescence may increase the risk of cognitive abnormalities and psychotic disorders.^[1,8-10] Use of cannabis at early age and high frequency are associated with a greater risk of problems ^[5,7,11]. Arendt et al. consider that this cannabis-induced psychosis is an early expression of schizophrenia in vulnerable individuals rather than part of the differential diagnosis ^[12]. Moore’s review reported a 40% higher risk of psychosis in subjects who occasionally used cannabis and a probability of 50% to 200% higher in regular cannabis users ^[13]. Swedish Conscripts Study (Andreasson et al.) of inductees into the military reported a risk for schizophrenia 2.4 times higher among those who had used cannabis by 18 years than among non-users ^[14,24]. This cannabis-induced psychosis is not easily distinguishable from Schizophrenic symptomatology, ^[15,19] although it has been characterized by more bizarre behavior, violence, panic, more hypomanic symptoms and agitation, and fewer hallucinations and less blunting of affect and incoherent speech.^[20,21]

Need of the current study

Studies have found cannabis associated psychosis a constellation of affective symptoms (euphoria, increased psychomotor activity), ^[16,17,18] whereas others have found similarity with schizophrenic symptomology of social withdrawal, thought disorder and disorganized behavior ^[19,22] so there is immense need to define the presenting features of this disorder in Indian population. Additionally phenomenology of the cannabis use disorder need to be explored to clearly define, identify and manage this population. Despite widespread use of cannabis there is lack of research data from most part of the world including India.

Aims and objectives:

Based on the existing literature we formulated following hypothesis that “Patients with cannabis associated psychosis have different symptom profile than other common psychiatric disorders, relating to variables of cannabis abuse e.g. dose, frequency, duration”.

To test the hypothesis following objectives were formulated

1. To assess variables of cannabis abuse in patients with cannabis associated psychosis.
2. To explore the relationship between variables of cannabis abuse, and individual symptom profile and total BPRS score.

Subjects and Methods:

Patients in whom there was temporal association of cannabis use with onset of psychotic illness were included in the study. The study included 30 consequentially admitted, Hindi speaking patients of 18-50 years of age at tertiary psychiatric centre in north India from March 2011 to July 2011. Patients with mental retardation, a significant medical condition compromising ability to participate, history of head injury with any documented cognitive sequele, and inability to provide informed consent were excluded from study. Patients having history of psychiatric illness prior to onset of cannabis abuse, predominant abuse/dependence of other psychoactive substance and having any other significant medical illness were also excluded from study.

Study design:

A cross sectional study of subjects who satisfied the inclusion criteria was carried out. After recording socio demographic data, each participant in the study was subjected to questionnaire regarding his cannabis abuse and brief psychiatric rating scale (BPRS). To measure the quantity of cannabis intake by individual indirect measure in form of average amount (INR) spent daily was inquired. The age of onset, duration of abuse, and cause of onset- accidental, casual, peer group and offer by elder family members were recorded. The history of cannabis abuse as well as psychiatric illness in other family members was inquired.

Results:

Majority of the participants were young male adults of the rural background. About 47 % (n-14) of them were unmarried and 60 % (n-18) were belonged to joint family. All the study participants were formally educated and at least one family member of about 43% (n-13) of participants had history of cannabis abuse.

As it has been shown in table 2 majority of the study participants were abusing cannabis for more than 10 years with mean duration of cannabis abuse 14.2 years. 50 % of the individuals experienced first cannabis intake before age of 13 years with average onset of cannabis use 14.5 years. Majority of the participants (66%) were daily cannabis abusers. More than 2/3 rd of the subjects was spending Rs. 15 per day on average over the cannabis. Onset of cannabis was occurred mostly due to influence of peer group (n-21). The symptoms that were associated with increased severity in majority of patients were hostility 25 (83%), excitement 23 (77%), and elevated mood, grandiosity, suspiciousness, distractibility and motor hyperactivity in more than 60% of individuals. Other symptoms that were present in severe to very severe form in more than half individuals were hallucinations, unusual thought content, uncooperativeness, and self neglect. Suicidability and tension was absent in 28(93%) of patients, depression and motor retardation was absent in 25(83%) of participants, guilt was absent in 70% of patients and blunted affect, conceptual disorganization and emotional withdrawal were completely absent in >60% of individual patients.

Correlation with duration of cannabis abuse

Long duration of abuse was negatively correlated with depression and hostility but other symptoms like suspiciousness, hallucinations, unusual thought content were positively correlated. Duration of cannabis abuse was significantly associated with total BPRS score (p-0.002). Patients with long duration of cannabis were presented with more severe form of psychosis than patients with short duration of cannabis abuse.

Correlation with Age of onset of cannabis abuse

Older age of onset of cannabis use was significantly associated with depression (p<0.001) and hostility (p-0.001). Younger age of onset was significantly correlated with anxiety (p-0.048), guilt (p-0.002), hallucinations (p-0.001), and unusual thought content (p-0.006). Total BPRS score was significantly correlated with younger age of onset.

Correlation with frequency of cannabis abuse

Frequency of cannabis abuse was significantly associated with self neglect (p-0.007) and tension (p<0.001). Majority of daily cannabis abuser patients (83%) had history of self neglect in range of severe to very severe form.

Correlation with amount spent over cannabis

The amount spent over cannabis was significantly correlated with anxiety (p-0.030), hallucinations (p-0.001), bizarre behavior (p<0.001), self neglect (p-0.01), blunted affect (p-0.024), emotional withdrawal (p-0.003), tension (p-0.001) and distractibility (p-0.028). Most of the symptoms significantly correlated with amount spent over cannabis belonged to the perceptual and thought spectrum. Frequency of cannabis use was not significantly correlated with total BPRS score (p-0.104) although amount spent over cannabis was significantly associated with total BPRS score (p-0.048). Individual in which onset occurred due to influence of peer group had more propensity of developing elevated mood (p-0.002), grandiosity (p-0.023), and conceptual disorganization (p-0.039). Family history of cannabis abuse predicted early onset of cannabis use onset compare to group with negative family history. Total BPRS score was positively correlated with significant value in regard to duration of cannabis abuse (p-0.002), amount spent daily over cannabis abuse. Earlier age of onset of cannabis abuse was associated with more severe psychotic disorder as measured by BPRS scale (p-0.037)

Discussion:

This study was aimed at determining clinical symptoms in relation to variables of cannabis abuse. All subjects were male. This could be attributable to low levels of substance use among females in general and cannabis in particular. Age range was wide and may be due to variation in genetic vulnerability to psychosis, dose of cannabis and duration of illness leading to variable age at presentation. Positive symptoms (motor hyperactivity, excitement, hostility, elevated mood, suspiciousness, grandiosity) were found at higher frequency than negative symptoms (blunted effect, emotional withdrawal and motor retardation). Hallucinations were present in only half of the participants. Other symptoms of the psychosis like conceptual disorganization and catatonic symptoms were absent. Our result was in support of Vani Kulhali and colleagues’ ^[23] finding that patients with cannabis associated psychosis had high positive scores (>5) on respective BPRS items were hostility 25 (83%), excitement 23 (77%), and motor hyperactivity, elevated mood, grandiosity, suspiciousness, distractibility in more than 60% of individuals. The least common symptoms were suicidability and tension 2 (6), depression and motor retardation 5 (15%), guilt was present in 30% of patients and blunted affect, conceptual disorganization and emotional withdrawal were completely absent in >60% of individuals. Most studies have reported that cannabis produces psychosis with prominent positive symptoms ^[16,1718]. Our findings are in keeping with these studies. Scores on BPRS reflected both the total intensity and the profile of psychopathology. Thus our findings largely confirm that reports of other authors that cannabis produces a psychosis with predominantly affective features and more of positive symptoms. Family history of drug disorders is regarded as risk factor for substance use including cannabis, whether it also results in increased vulnerability to cannabis psychosis is not clear.

Conclusions

The implication of this study is that cannabis contributes in causing and modifying psychosis. Several noteworthy findings emerged from this heterogeneous sample of cannabis associated psychosis. First the severity of psychotic episode was significantly associated with younger age of onset of cannabis abuse and increased spending was associated with more severe psychotic episode. Second family history of psychosis was not associated with increased severity of cannabis abuse, although family history of psychosis predicted more severe excitement, elevated mood and grandiosity and early onset of cannabis abuse.

Limitations of the study

1. As this was a cross sectional study and cannabis variables were obtained from interview possibility of “recall bias” can`t be ruled out.
2. It was not possible to measure the amount of cannabis in unit time.
3. Proxy used to represent this variable may not be representative of active ingredient of delta- 9THC.
4. We have to rely on the subjects `self- report` of not using any other substances and were unable to objectively verify this report. Thus, the possibility that some symptoms were related to abstinence from other drugs cannot be completely excluded.
5. Wide age range could be a drawback of study since homogeneity in duration of illness and amount of cannabis abuse could not be ensured.