Psychiatric manifestations in Neuronal ceroid lipofuscinoses.

BACKGROUND

Neuronal ceroid lipofuscinoses (NCLs) are rare genetic neurodegenerative disorders characterized by progressive cognitive, motor, and visual decline. The transition from supportive care to emerging disease-modifying therapies has reshaped the clinical landscape of NCLs and highlighted the urgent need for sensitive and clinically meaningful outcome measures beyond traditional motor and survival endpoints. Psychiatric manifestations, which profoundly affect daily functioning and quality of life, represent a potentially valuable yet underexplored domain.

METHODS

We conducted a systematic review following PRISMA guidelines to synthesize current evidence on the prevalence, clinical spectrum, developmental trajectories, assessment strategies, and management of psychiatric manifestations across NCL subtypes.

RESULTS

Psychiatric symptoms are highly prevalent across NCL forms and encompass a broad clinical spectrum, including early emotional and behavioral dysregulation, neurodevelopmental-like features, anxiety and depressive symptoms, obsessive-compulsive phenomena, and psychotic-spectrum manifestations. Their expression varies according to age and disease stage and reflects a multifactorial interplay between neurodegeneration, disrupted neurodevelopment, autonomic and sensory dysfunction, cognitive decline, genetic modifiers, and environmental factors. Despite their clinical relevance, management remains largely empirical and palliative, relying on psychotropic medications and supportive interventions with limited evidence and frequent adverse effects. Furthermore, psychiatric assessment tools are inconsistently applied, predominantly in CLN3 disease, and terminology remains heterogeneous and non-standardized, hindering cross-study comparability and robust phenotypic characterization.

CONCLUSIONS

Psychiatric manifestations represent a core and developmentally modulated component of NCLs. The lack of standardized language and validated, age-appropriate assessment instruments constitute a major barrier to clinical care and research. Systematic phenotyping and harmonized measurement strategies are urgently needed to improve management and to integrate psychiatric outcomes into future natural history studies and therapeutic trials.