Which dopamine pathway is responsible for negative symptoms of schizophrenia?

A. Dopamine. Tourette’s syndrome is primarily associated with dopamine dysregulation, particularly increased dopamine activity in the basal ganglia. This overactivity leads to excessive, involuntary motor and vocal tics. Dopamine-blocking medications, such as antipsychotics (e.g., haloperidol, risperidone), can help reduce tic severity.

B. Serotonin. While serotonin plays a role in mood regulation and impulse control, it is not the primary neurotransmitter involved in Tourette’s. However, selective serotonin reuptake inhibitors (SSRIs) may be used to treat co-occurring obsessive-compulsive disorder (OCD) and anxiety symptoms in Tourette’s patients.

C. Glutamate is the brain’s primary excitatory neurotransmitter, involved in learning and memory. While some research suggests glutamate imbalances may contribute to tic severity and compulsive behaviors, dopamine remains the key neurotransmitter in Tourette’s pathology.

D. GABA is the brain’s primary inhibitory neurotransmitter, responsible for reducing neural excitability. Though impaired GABAergic inhibition may contribute to tic generation, the main abnormality in Tourette’s involves dopamine overactivity in the basal ganglia and cortico-striatal-thalamo-cortical circuits.

A. Sudden onset of psychotic symptoms in less than a month. According to the DSM-5, brief psychotic disorder is characterized by a sudden onset of delusions, hallucinations, disorganized speech, or disorganized behavior that lasts at least one day but less than one month, with eventual full recovery.

B. Sudden onset of psychotic symptoms in less than two months. The DSM-5 criteria do not define brief psychotic disorder with a two-month duration. If symptoms persist beyond one month, another diagnosis, such as schizophreniform disorder, may be considered.

C. Sudden onset of psychotic symptoms in less than one year. Psychotic symptoms lasting up to one year are more indicative of schizophrenia or schizoaffective disorder, not brief psychotic disorder.

D. Sudden onset of psychotic symptoms in less than six months. Psychotic symptoms lasting longer than one month but less than six months are consistent with schizophreniform disorder, rather than brief psychotic disorder.