Individuals with situational phobias may develop residual problems as a result of their phobias. Because of the need to avoid the feared situation, social isolation may result. In addition, the inability to engage in certain activities may lead to depression, especially if the phobia interferes with relationships, jobs, and daily activities. For some individuals, their phobias can lead them to abuse alcohol or drugs, further complicating their condition and recovery. Although the success of treating individuals with specific phobias is very high, the existence of co-existing conditions may hinder or complicate treatment.