What it is: Cognitive behavior therapy (CBT) is based on the belief that our thoughts, feelings and actions all influence one another, so making changes on any of these three levels will affect the other two.“All situations we find ourselves in can be split into how we think about them, what we’re doing in them, and how we’re feeling in them,” says Simon Rego, Psy.D., director of psychology training at Montefiore Medical Center in New York. “CBT says, we know that how people feel is influenced by and at the same time can influence what they’re thinking and what they’re doing in situations.”CBT practitioners help people change their thought and behavior patterns, which influences their emotions. “Unlike the more traditional psychotherapies that really go back and look at root causes, CBT tends to start with the here and now,” Rego says. Therapists teach clients skills that they practice on a day-to-day basis, such that by the end of the process, they’ve internalized new beliefs and ways of acting. “You’re learning to almost—by the end of therapy—become your own little mini-CBT therapist, yourself,” Rego says.MORE: Building Better Sleep Habits with CBTHow it works: CBT starts with an assessment of the client’s history, meant to elucidate how the disorder developed and what’s keeping it going. In the next phase—what’s called a “psycho-education phase”—the therapist teaches the client about the diagnosis and about CBT itself.But the core of CBT is practice. Clients are given homework—both written assignments and activity assignments—each session, and are expected to return with notes. A client who’s dealing with anxiety might learn to identify the automatic, negative thoughts that take place when she’s anxious and, instead of letting them spiral out of control, challenge them by looking for errors in logic and coming up with more realistic thoughts to replace them. Simultaneously, she might practice new behaviors: instead of avoiding the things that make her anxious, which allows the worry to continually grow, she’d slowly increase her exposure until she could approach the problem with ease.“You have to be willing to invest in the process of learning,” Rego says. “It’s really seeing things and doing things in a brand new way, so we believe it takes a lot of practice to get there.”Who it fits: CBT asks clients to change the way they’ve always thought and behaved, so it requires a willingness to try new options that might seem scary at first. Clients also have to be ready to do the work between visits and “to follow a highly structured treatment,” Rego says.Shown to treat: Anxiety, depression, anorexia, bulimia, manic-depression, schizophrenia, insomnia, and substance abuse problems.Duration: 16-20 visits, starting weekly but gradually tapering to every two or three weeks to allow clients to practice on their own. Where to find a cognitive behavioral therapist: See the Association for Behavioral and Cognitive Therapies for an extensive list of CBT practitioners. The Academy of Cognitive Therapy and the American Board of Professional Psychology offer smaller lists of thoroughly vetted practitioners.MORE: Bust a Bad Mood with the ABCD Method