Heavy cannabis use (HCU) is linked to changes in both brain structure and function, even in individuals without a cannabis-use disorder or other major mental illnesses. This study used multimodal MRI to examine grey matter volume and intrinsic neural activity in 24 heavy users and 16 controls. Two distinct brain component patterns differed between groups: one involving the cerebellum, temporal, and thalamic regions (structural), and another involving frontal and parietal regions (functional). These patterns correlated with specific cannabis-use behaviors. Additionally, the structural changes were associated with the serotonergic system, while functional changes were linked to serotonergic, dopaminergic, and μ-opioid receptor systems, offering new insights into the neural mechanisms of heavy cannabis use.
Patients with schizophrenia often experience fragmented time and distorted spatial perception, such as abnormal interpersonal distance and orientation, which can detach them from reality and complicate therapy. Despite this, these experiences remain understudied due to a lack of standardized measurement tools. Based on spatiotemporal psychopathology (STPP), a clinical rating scale called the Scale for Space and Time Experience in Psychosis (STEP) was developed. The German version of STEP assesses 14 spatial and 11 temporal phenomena across 25 items. It demonstrates high internal consistency (Cronbach's alpha = 0.94) and significant correlation with the Positive and Negative Syndrome Scale (PANSS; p < 0.001), offering a valuable instrument for German-speaking countries.
Mindfulness-based therapy (MBT) during the first month of opiate abstinence produces distinct changes in default mode network (DMN) connectivity. In 32 opiate-dependent patients assigned to either MBT or treatment as usual (TAU), those receiving MBT showed increased mindfulness scores after four weeks. Within the anterior DMN, MBT patients had decreased connectivity in the right inferior frontal cortex compared to TAU, and within the MBT group, decreased right superior frontal cortex connectivity emerged after treatment. Inferior frontal cortex function correlated with mindfulness measures. MBT may be useful during opiate abstinence, with specific DMN connectivity changes associated with the therapy.