Marijuana Makes Schizophrenics Smarter

OK, so it’s not as simple as the title above suggests. However, Spanish researchers have found that cannabis use among patients with schizophrenia is associated with greater cognitive function and premorbid adjustment than seen with patients with schizophrenia who were not cannabis users.

"Studies in healthy individuals have established that acute and chronic consumption of cannabis is associated with cognitive impairments and to transient schizophrenia-like positive, negative, and cognitive symptoms," explained José Manuel Rodríguez-Sánchez, University Hospital Marqués de Valdecilla, Santander, Spain, and colleagues. The researchers added that previous studies looking at cannabis use in patients with early-phase schizophrenia have come to conflicting conclusions.

Thus, the researchers conducting the current study looking at 104 patients with a first episode of non-affective psychosis and 37 mentally healthy controls, all age 15-60 years. Cannabis users made up 47 of the 104 schizophrenia patients and none of the controls. They found that on almost all cognitive test—aside from the Finger Tapping and Grooved Pegboard tests—controls outperformed patients with schizophrenia.

However, among those with the disease, non-cannabis users were outperformed by users on tests of attention and executive function at both baseline and 12 months of treatment. Further, cannabis users displayed better social premorbid adjustment than did non-users, particularly in early life.

The team concluded that first-episode “schizophrenia patients that use cannabis do not seem to show a worse cognitive performance with respect to patients that do not use the substance. On the contrary, they apparently perform better in certain cognitive functions…Cannabis user patients appear to comprise a subgroup of patients with a better premorbid adjustment and baseline frontal cognitive functions.”

For More on This and Related Stories:

• Read the article published September 9 online in Schizophrenia Research
• EEG Predicts Response to Medication for Schizophrenia
• Association Between Urban Living and Psychotic Disorders
• Combining Medication and Psychosocial Treatments may Benefit Patients with Early-Stage Schizophrenia