An ounce of prevention is worth a pound of cure is how the old saying goes, and when it comes to mental health, nothing could be more true. The cost of depression is high, both for the people struggling with the disease and for all of those in their work, family and social circles. Depression can rob a family of its parents or a child of his or her childhood. It steals cash from businesses in terms of lost productivity, and robs individuals of enjoyment of life. And yet the lion\u2019s share of the depression-related research has focused on treatment, not prevention, of this disease. Understanding how to prevent depression, especially among those already considered to be at high risk for developing the disease, is an important and valuable contribution to the research literature. Enter cognitive behavioral therapy (CBT), revised for teens identified as at high risk for depression. Researchers selected a group of over 300 teens who had either experienced depressive symptoms (but never actually met criteria for full-blown clinical depression themselves) or had at least one parent who had been diagnosed with depression, or both. This \u201cdouble whammy\u201d of having experienced some symptoms plus having a parent diagnosed with depression increases the risk of developing depression significantly. The researchers then split the 300 teens into two groups, and one group received the prevention training program\u2014a course specially designed to help teens use CBT to prevent depression by training them to \u201crethink\u201d their symptoms and \u201cboss back\u201d the negative cognitions. The other group, the control group, did not receive the CBT intervention. CBT has been successfully used to treat young children struggling with impulse control, anger issues and anxiety. Teaching children, teens and adults to become aware of the relationship between thoughts, behaviors and emotions can be life changing and is frequently cited as one of the most helpful psychotherapeutic interventions used. The success reported in preventing depression in those identified as high risk was significant. After more than two years, the teens who received the CBT-based intervention were reporting fewer depressive symptoms and fewer depressive episodes than those who did not participate in the CBT program. An additional aspect contributing to the success of this program may have been the way in which the prevention service was delivered: the teens attended a group program that included weekly session for eight weeks, then additional follow up sessions every six months. For teens, this may have been as important as the content of the course, as contact with peers and developing positive connections with peers is a key element of the adolescent developmental process. The group setting probably helped ease a sense of isolation and stigma that can be such a debilitating aspect of depression. Learning skills and techniques to improve mood and prevent depression in a one-on-one setting in a therapist\u2019s office may also work well for some teens and adults, but a structured group setting is, in general, an excellent way to provide services to teens. What Is CBT? How Can It Be Adapted for Prevention? CBT is a very common therapeutic technique with ancient roots. There is a quote from Shakespeare\u2019s Hamlet that summarizes CBT and does a great job of showing the relationship between thoughts, mood and behavior. Hamlet is depressed after his father\u2019s untimely death and his mother\u2019s hasty remarriage. He lives in Denmark, and when chatting with his friends he refers to Denmark as a prison (how many times have you heard teens refer to their hometown, their high school or their family\u2019s rules in this way?) His friends are surprised and disagree; they say, \u201cI do not think it is.\u201d Hamlet\u2019s answer is the nugget of CBT, explained as well as any therapist could: \u201cThere is nothing either good or bad, but thinking makes it so. To me it is a prison.\u201d Translation? Your attitude, your thoughts or your way of thinking about things are what determine whether they or good or bad. For example, let\u2019s say you get a promotion at work. Is this a good thing or a bad thing? If you tell yourself it is a good thing because you\u2019ll have more people working for you to help with projects, you\u2019ll get more money, you\u2019ll enjoy more respect\u2014you\u2019ll think positively about the promotion and this will lead to happy, positive emotions. If you think that the promotion will be a disaster because people will be jealous or angry that they were passed over, your workload will increase but the raise in pay isn\u2019t enough, or you think you can\u2019t manage the increased responsibilities, then the promotion will be considered a bad thing, you\u2019ll think negative thoughts and you\u2019ll be likely to feel anxious and depressed. CBT has traditionally been used to treat mental illnesses once they have been diagnosed. Teaching healthy teens to question their thought processes and be critical about how they think, and to notice the relationship between thoughts and emotions before that relationship has become entrenched in negativity is a positive and proactive way to \u201cinoculate\u201d children and teens against mental illness.