Cannabis use predicts worse clinical outcomes in newly psychotic patients

A recent observational study found that feelings of hopelessness and clinical depression operate as psychological pathways that maintain psychotic symptoms in people who develop psychosis after heavy cannabis use. When patients continued using cannabis, their feelings of depression and negative future expectations worsened, predicting a markedly higher risk of psychiatric relapse. The research was published in the journal Addictive Behaviors.

Psychosis is a mental health condition where individuals experience a detachment from reality. This state often involves hallucinations, which are seeing or hearing things that are not present, or delusions, which are strongly held false beliefs. While some psychotic episodes are part of primary psychiatric disorders like schizophrenia, others are directly triggered by substance use. This phenomenon is known as substance-induced psychosis.

Over the past several decades, medical professionals have documented a relationship between frequent cannabis consumption and an increased risk of developing psychotic disorders. This risk appears to rise based on the frequency of use and the potency of the cannabis consumed. Patients who experience cannabis-induced psychosis often present with distinct features compared to those with traditional schizophrenia. They typically retain better awareness of their condition and suffer fewer cognitive deficits, which can make them acutely aware of their psychological distress.

While the link between heavy marijuana use and initial psychotic breaks is well documented, the underlying psychological mechanisms that keep these symptoms active remain incompletely understood. Valerio Ricci, a researcher at the University of Turin in Italy, and his colleagues designed a study to investigate the emotional components of this dynamic. They focused on two specific mental states: clinical depression and hopelessness. In psychological terms, hopelessness is defined as a persistent system of negative expectations regarding oneself and the future.

To understand how these factors relate, the researchers followed a group of 72 young adults over a two-year period across three psychiatric centers in Northern Italy. The participants were predominantly male and all between the ages of 18 and 35. Each individual had recently experienced their first psychotic episode, and clinical evaluations determined this episode was directly linked to heavy cannabis use rather than an underlying primary psychotic disorder. Prior to their mental health crisis, nearly three-quarters of the participants had consumed cannabis on a weekly basis, while a substantial portion used it every day.

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The research team evaluated the participants at the beginning of the study, and then conducted follow-up assessments at six, twelve, and 24 months. During these visits, clinicians measured the severity of the subjects’ depression, feelings of hopelessness, and overall psychotic symptoms using standardized psychological scales. To track drug consumption, the researchers used a calendar-based memory aid to help participants accurately recall how many days they had consumed cannabis in the preceding month. They also gathered information on the participants’ social functioning and their adherence to prescribed psychiatric medications.

The collected data revealed a strong relationship between the participants’ mood states and the trajectory of their psychosis. High levels of depression and hopelessness each independently predicted more severe psychotic symptoms over the two-year period. Participants who scored high in these two emotional categories at the beginning of the study were highly likely to experience a sluggish recovery.

The research identified three general recovery paths: rapid improvement, gradual improvement, and minimal improvement. Elevated feelings of depression and hopelessness early on were strong predictors that a patient would fall into the minimal improvement category. These emotional burdens also predicted worse global functioning, making it difficult for the individuals to return to typical social and occupational activities.

The research team used statistical modeling to determine if depression and hopelessness served as an active link between ongoing cannabis use and persistent hallucinations or delusions. They found that these two emotional states partially mediated this relationship, explaining a sizable portion of the statistical effect. This suggests that ongoing cannabis use elevates the patients’ feelings of depression and hopelessness. Those worsened mood states subsequently feed the continuation of the psychotic symptoms.

Avoiding cannabis after the initial psychotic episode was a challenge for many participants in the study. Just over 60 percent of the group continued consuming the drug during the two-year follow-up period. This ongoing use was consistently linked to greater levels of both depression and hopelessness at every evaluation point. Those who abstained from the drug fared substantially better emotionally and psychologically over time.

The combination of continued substance use and severe mood disturbances created a uniquely dangerous environment for psychiatric relapse. During the follow-up period, about 43 percent of the observed participants experienced a relapse of their psychotic symptoms. Patients who combined continued cannabis use with a sense of hopelessness and clinical depression confronted a relapse risk that was more than four times higher than those avoiding these compounded risk factors.

The study also highlighted a difference between how depression and hopelessness respond to traditional medical care. About 38 percent of the patients were prescribed antidepressant medications, alongside their primary antipsychotic treatments. When participants consistently took their prescribed medications, their depressive symptoms lessened notably. However, this high medication adherence was not statistically significant in improving their feelings of hopelessness.

This outcome implies that depression and hopelessness possess distinct foundations in the human brain. The researchers note that depressive symptoms are more responsive to pharmacological interventions that target chemical messengers. Hopelessness appears to be a more entrenched cognitive mindset shaped by personal beliefs, perceived stigma, and lifestyle coping resources. As a result, pills alone might be insufficient to alleviate a patient’s negative view of the future without the addition of specialized talk therapies.

The researchers also note the importance of pragmatic approaches for patients who struggle to immediately quit using drugs. Because a majority of the study population continued using cannabis despite the negative outcomes, medical professionals may need to embrace harm reduction strategies. These strategies might include helping a patient gradually reduce how often they use cannabis, or encouraging them to switch to lower-potency strains. Exploring why the patient uses the drug could help them build self-awareness and increase their motivation to change their habits.

The study features limitations that provide context for the findings. Because the research utilized an observational design, the authors cannot prove that cannabis use directly causes the mood disturbances, or that mood disturbances directly cause psychosis to outlast its typical duration. The researchers propose that a self-reinforcing cycle might exist in which mood disturbances prompt individuals to use cannabis to cope, which in turn worsens their psychiatric symptoms. They note this dynamic requires direct testing in future experimental environments.

Additionally, the study relied entirely on the patients accurately reporting their own substance use. The clinical team did not use biological markers, such as urine screenings or hair analyses, to verify how much active cannabis was in the participants’ bodies. Unmeasured variables, such as a genetic predisposition to mental illness or unseen environmental stressors, might also influence the mathematical relationships observed in the patient data. The relatively sparse number of actual relapse events in the data pool also limits the generalizability of the exact risk calculations.

Future research may utilize brain imaging technology to observe how cannabis impacts the specific neural circuits involved in emotional regulation. Scientists could also organize clinical trials that test specialized psychological therapies aimed specifically at reducing hopelessness in patients dealing with a recent psychotic episode. Testing these integrated approaches may help medical professionals develop better interventions for young adults navigating the aftermath of extreme mental health distress.

The study, “The role of hopelessness and depression in cannabis-induced first-episode psychosis: a 24-month prospective study,” was authored by Valerio Ricci, Giovanni Martinotti, and Giuseppe Maina.