Abstract
BACKGROUND: Anorexia nervosa (AN) is characterized by heterogeneous clinical manifestations, which complicates diagnosis and treatment. It is important to define the clinical variants and therapeutic targets for AN. AIM: To identify empirical patient phenotypes within the AN diagnostic category using Latent Class Analysis (LCA) of clinically assessed psychopathological symptoms. METHODS: Psychiatrists clinically assessed psychopathological symptoms of AN using an original checklist (57 symptoms in total) and the Mini-International Neuropsychiatric Interview (M.I.N.I.) was used to identify mental disorders. Patients completed the Symptom Check List-90-Revised questionnaire (SCL-90-R) to self-assess psychopathological symptoms and distress. Clinically homogeneous patient subgroups were identified using LCA. RESULTS: A total of 115 patients with AN were examined. Based on the LCA, four patient groups (C1-C4) were identified, with high classification certainty (R(2)=0.908), model significance (p<0.001), and clear separation of the latent groups (class separation index = 0.957). ED-related symptoms were key determinants of class formation only in 68 patients (59%) - those in C1 and C3. No statistically significant differences were found between classes on any SCL-90-R subscales or most M.I.N.I. diagnoses. In C1 (n=41), core ED symptoms dominated: dysmorphophobia, fears related to eating, weight gain, loss of control. In C2 (n=39), low frequencies are observed for core ED symptoms; this group was characterized by a high incidence of sleep disturbances, anxiety, apathy, melancholy, and anhedonia. C3 (n=27) represents a polymorphic clinical profile with a combination of core ED symptoms, affective symptoms, thought disorders, cognitive impairments, and sleep disturbances. C4 (n=8) was defined by the presence of hypochondriacal concerns, somatoform autonomic symptoms, and apathy; none of the core ED symptoms were typical for C4. CONCLUSION: Four empirically derived clinical phenotypes of AN were identified, each characterized by a distinct symptomatic profile. Each phenotype was defined by specific combinations of core ED symptoms and general psychopathological manifestations.