Neurological impairment is usually present with inhalant abuse, but it is difficult to determine whether these problems precede or are the result of inhalant abuse. Abusers should be assessed for any learning difficulties that may interfere with treatment or contribute to disruptive behaviour. Testing should be repeated after several months to assess improvement. It is not known conclusively whether neurological damage from inhalant abuse is reversible, but anecdotal reports suggest that dramatic improvement in functioning can occur over several weeks of treatment.