The Forced Swim Test is a specific behavioral test typically used in rodents to study feelings of apathy and motivation. First, the subject’s behavior is altered in some way, typically through a drug or a synthetic device. Then, the subject is placed in a bucket of water. The longer the rodent swims in the bucket, the greater its level of motivation. On the other hand, the longer the rodent spends without moving, the greater its level of apathy. This test has been used to study a wide variety of drugs to predict their impact on the central nervous system. For example, rodents who are exposed to SSRIs have higher levels of serotonin, which could cause them to swim harder for longer, indicating that the drug could be effective at treating depression.