Which of the following ADHD medications is not a stimulant?

A. Mesolimbic pathway is associated with reward, motivation, and emotions and is hyperactive in schizophrenia, leading to positive symptoms such as hallucinations, delusions, and disorganized thinking. Antipsychotic medications work by blocking dopamine (D2) receptors in this pathway, reducing psychotic symptoms.

B. Nigrostriatal pathway controls motor function and coordination. Dopamine blockade in this pathway leads to extrapyramidal symptoms (EPS) such as tremors, rigidity, and tardive dyskinesia, which are common side effects of first-generation antipsychotics (typical antipsychotics).

C. Tuberoinfundibular pathway regulates prolactin secretion. Dopamine inhibits prolactin release, so blocking D2 receptors with antipsychotics leads to increased prolactin levels, causing gynecomastia, galactorrhea, and menstrual irregularities.

D. Mesocortical pathway is responsible for cognition, motivation, and emotional regulation. In schizophrenia, this pathway is hypoactive, contributing to negative symptoms such as apathy, social withdrawal, and cognitive impairment.

A. Hallucinations are a core positive symptom of schizophrenia and involve false sensory perceptions without an external stimulus (e.g., hearing voices, seeing things that are not there). According to the DSM-5, hallucinations are one of the three essential symptoms that must be present for a diagnosis.

B. Delusions are fixed, false beliefs that persist despite evidence to the contrary (e.g., persecutory delusions, grandiose delusions). Delusions are a hallmark symptom of schizophrenia and are required as a diagnostic criterion if present.

C. Disorganized speech reflects disorganized thinking, a key symptom of schizophrenia. It includes incoherence, tangentiality, and word salad, demonstrating the cognitive dysfunction associated with the disorder. If disorganized speech is present, it fulfils one of the primary diagnostic criteria.

D. Negative symptoms such as avolition, anhedonia, alogia, and flat affect, are common in schizophrenia but are not required for diagnosis. According to the DSM-5, at least one of the following three symptoms hallucinations, delusions, or disorganized speech must be present to meet the diagnostic criteria for schizophrenia.