Neurological Soft Signs in Cannabis Use Disorder with or without Psychosis: A Comparative Study from India

The purpose of this study was to assess and compare neurological soft signs in patients of cannabis use disorder (CUD) with and without co-occurring psychosis in a treatment-seeking sample.

We included 30 right-handed male subjects aged 18-65 years diagnosed with CUD (as per DSM-5) without any co-occurring psychiatric disorder in group I and those with co-occurring non-affective psychosis in group II. Group III consisted of 30 age and sex-matched, right-handed, healthy subjects with no psychiatric or medical conditions. Neurological Evaluation Scale (NES) was applied to measure neurological soft signs across the groups. We also used the Severity of Dependence Scale (in CUD with or without co-occurring non-affective psychosis groups) and Scale for the Assessment of Positive Symptoms, Scale for the Assessment of Negative Symptoms, Barnes Akathisia Rating Scale, Abnormal Involuntary Movements Scale, and Simpson Angus Scale (in CUD with co-occurring non-affective psychosis group) .

Our data suggested higher total NES mean scores in CUD with (20.53 ± 13.77) or without co-occurring non-affective psychosis groups (15.93 ± 9.86) as compared to healthy controls (6.20 ± 5.40) (χ² = 23.12; p < .001). However, there were no differences between cannabis use disorder with or without co-occurring non-affective psychosis groups. The mean of subdomain scores of motor incoordination, sequencing of complex motor tasks, sensory integration, and others was significantly higher in CUD with or without co-occurring non-affective psychosis groups compared to healthy controls.

Impairment in neurological soft signs is present in patients with CUD regardless of a co-occurring psychosis. Cannabinoids might be interacting with the brain circuits known to be involved in schizophrenia.