Akademik Veri Yönetim Sistemi
17th International Congress on Psychopharmacology & Child and Adolescent Psychopharmacology / Psychotherapy, Antalya, Türkiye, 15 - 18 Nisan 2026, ss.0-1, (Özet Bildiri)
Substance use disorders (SUDs) are among the most clinically consequential comorbidities in schizophrenia, substantially influencing illness onset, symptom burden, treatment response, relapse liability, and long-term functional outcome. In the context of an increasingly accessible and high-potency global drug market, this comorbidity has become even more clinically relevant. Rather than representing a coincidental co-occurrence, SUD in schizophrenia is best understood as a major determinant of poor prognosis, associated with impaired adherence, recurrent hospitalization, suicidality, and excess mortality. Large cohort and review data suggest that nearly half of patients with schizophrenia meet criteria for at least one SUD, with tobacco, alcohol, cannabis, and cocaine among the most commonly implicated substances (1, 2).
Schizophrenia and addiction appear to share, at least in part, a common neurobiological substrate centred on dysregulation of mesolimbic and mesocortical dopaminergic pathways. Psychoactive substances acutely enhance striatal dopamine transmission, whereas chronic exposure induces neuroadaptations that may increase psychosis vulnerability and sustain compulsive substance use (1). In parallel, hypodopaminergic states associated with chronic substance exposure may aggravate anhedonia and negative affect, thereby reinforcing repeated substance seeking. Within schizophrenia, impairments in reward processing, executive dysfunction, and hypofrontality may further promote self-medication and reduced control over use. At the behavioural level, recurrent intoxication, withdrawal, and non-adherence establish a cycle that increases relapse risk and may diminish antipsychotic responsiveness over time (1-3)
Clinical management should begin with systematic screening for substance use, careful distinction between primary psychosis and substance-induced phenomena, and an individualized relapse formulation incorporating current use patterns, withdrawal states, and psychosocial stressors. Treatment is most effective when delivered through an integrated model combining pharmacotherapy, motivational interviewing, cognitive-behavioural interventions, case management, and social rehabilitation. Compared with sequential or parallel models of care, integrated approaches appear more effective in sustaining engagement and reducing relapse (1, 2).
Antipsychotic selection is particularly important in this population. Available evidence suggests that the choice of antipsychotics may influence both the risk of developing comorbid SUD and subsequent relapse patterns. Clozapine appears to confer the strongest protection against relapse and may also reduce the risk or persistence of substance use (2, 3). Long-acting injectable antipsychotics may provide additional benefit, particularly in patients with poor adherence, by improving treatment continuity and reducing the likelihood of relapse. While second-generation antipsychotics remain the usual first-line option overall, partial dopamine agonists such as aripiprazole, cariprazine, and brexpiprazole also appear promising in selected patients, although long-term comparative data remain limited. Given the heightened burden of metabolic, infectious, and social morbidity in dual-diagnosis populations, ongoing physical health surveillance should be considered an integral component of care (1, 2).
In sum, SUD in schizophrenia is a major driver of treatment resistance and relapse. Early detection, individualized antipsychotic treatment, and integrated multimodal care remain the most defensible clinical framework for improving outcomes in this highly vulnerable population (1-3).
Keywords: schizophrenia, substance use disorders, treatment resistance, relapse, integrated treatment