in DSM). Empirical research into the efficacy of ISTDP, and other brief psychodynamic psychotherapies is active. There are now over 60 published outcome studies in ISTDP including 40 randomized controlled trials for depression, anxiety, personality, somatic symptom and substance use disorders. There are also over 20 studies showing the cost effectiveness of the method through reducing doctor visits, medication costs, hospital costs and disability costs. Summary of cost effectiveness studies to 2018 ISTDP has been investigated for: Personality Disorders Depression and Treatment Resistant Depression Anxiety Disorders Functional Neurological Disorders Somatic Symptom Disorders: at least 20 studies as of October 2019 Cost effectiveness studies: at least 22 studies as of October 2019: As an Adjunct to Care in Severe Mental Disorders Substance Use Disorders A Cochrane systematic review examined the efficacy of short-term psychodynamic psychotherapies for common mental disorders such as depression, anxiety and personality disorders. Without distinguishing between different forms of STDP from Davanloo's ISTDP, modest to large short-term gains were reported for a broad range of people experiencing common mental disorders. Further research is required to determine the effectiveness and long term benefits of psychodynamic psychotherapies for common mental disorders. Neuroscientist and Nobel Prize winner, Eric Kandel refers to Davanloo's technique and its effectiveness in providing relief from emotional disturbances. Relationship to Cognitive Therapy Cognitive therapy (CT), developed by Aaron T. Beck, focuses on illogical thoughts as the main driver of emotional difficulties. These beliefs, such as, "Everything I attempt inevitably fails," are postulated to cause emotional states like depression or hopelessness. The therapist collaborates with the patient to determine which faulty cognitions are currently accepted by the patient as true. Together, the patient and therapist discover these cognitions and collaboratively explore the evidence for and against them. Relief of symptoms comes from replacing unfounded cognitions with more reality-based thoughts. CBT has been shown effective in numerous trials, particularly for depression and anxiety disorders. While ISTDP accepts the presence of faulty cognitions, the causality is thought to be reversed. The ISTDP therapist would posit that unconscious emotions lead to unconscious anxiety, which is managed by unconscious defences. These defences can certainly include hopeless, helpless, or self-deprecating cognitions. Rather than examining evidence for and against a thought like, "I am unable to know my own true feelings," an ISTDP therapist might say, "If you adopt that position, which is essentially a position of helplessness, we will not get to the