This study, based on the ‘Servizi Territoriali Associati per la Ricerca’ (STAR) Network Depot Study nationwide baseline data, explored whether individual symptoms severity and clusters might influence the prescription of paliperidone palmitate 1-month (PP1M) vs. aripiprazole monohydrate. The Brief Psychiatric Rating Scale (BPRS) was used to assess psychopathology and relevant symptoms clusters. Drug Attitude Inventory, 10 items, was used to test attitude towards medications. Adherence to treatments was rated according to the Kemp seven-point scale. We assessed for eligibility 451 individuals and, among them, we included 195 subjects (n = 117 who started PPM1 and n = 78 aripiprazole monohydrate). Individuals were comparable in terms of age, gender, treatment years, recent hospitalizations, previous long-acting injectable antipsychotic treatments, additional oral treatments, attitude toward drugs, medication adherence, and alcohol/substance-related comorbidities. Subjects starting PP1M presented higher BPRS overall (P = 0.009), positive (P = 0.015), and negative (P = 0.010) symptom scores compared to subjects starting aripiprazole monohydrate. Results were confirmed by appropriate regression models and propensity score matching analysis. No differences were found comparing the other BPRS subscale scores: affect, resistance, and activation. Clinicians may be more prone to prescribe PPM1, rather than aripiprazole monohydrate, to subjects showing higher overall symptom severity, including positive and negative symptoms. No additional clinical factors influenced prescribing attitudes in our sample.