diff --git a/bmt/toolkit.py b/bmt/toolkit.py
index 79bf629..b61da7a 100644
--- a/bmt/toolkit.py
+++ b/bmt/toolkit.py
@@ -441,22 +441,24 @@ def get_associations(
             A list of elements
 
         """
+        filtered_elements: List[str] = list()
+        inverse_predicates: Optional[List[str]] = None
         subject_categories_formatted = []
-        for sc in subject_categories:
-            sc_formatted = format_element(self.get_element(sc))
-            subject_categories_formatted.append(sc_formatted)
         object_categories_formatted = []
-        for oc in object_categories:
-            oc_formatted = format_element(self.get_element(oc))
-            object_categories_formatted.append(oc_formatted)
         predicates_formatted = []
-        for pred in predicates:
-            pred_formatted = format_element(self.get_element(pred))
-            predicates_formatted.append(pred_formatted)
         association_elements = self.get_descendants("association")
-        filtered_elements: List[str] = list()
-        inverse_predicates: Optional[List[str]] = None
-        if predicates_formatted:
+        if subject_categories:
+            for sc in subject_categories:
+                sc_formatted = format_element(self.get_element(sc))
+                subject_categories_formatted.append(sc_formatted)
+        if object_categories:
+            for oc in object_categories:
+                oc_formatted = format_element(self.get_element(oc))
+                object_categories_formatted.append(oc_formatted)
+        if predicates:
+            for pred in predicates:
+                pred_formatted = format_element(self.get_element(pred))
+                predicates_formatted.append(pred_formatted)
             inverse_predicates = list()
             for pred_curie in predicates_formatted:
                 predicate = self.get_element(pred_curie)
@@ -466,6 +468,8 @@ def get_associations(
                         inverse_predicates.append(inverse_p)
                 inverse_predicates = self._format_all_elements(elements=inverse_predicates, formatted=True)
 
+
+
         if subject_categories_formatted or predicates_formatted or object_categories_formatted:
             # This feels like a bit of a brute force approach as an implementation,
             # but we just use the list of all association names to retrieve each