Multimodal therapy (MMT) is an approach to psychotherapy devised by psychologist Arnold Lazarus, who originated the term behavior therapy in psychotherapy. It is based on the idea that humans are biological beings that think, feel, act, sense, imagine, and interact—and that psychological treatment should address each of these modalities. Multimodal assessment and treatment follows seven reciprocally influential dimensions of personality (or modalities) known by their acronym BASIC I.D.: behavior, affect, sensation, imagery, cognition, interpersonal relationships, and drugs/biology.
Multimodal therapy is based on the idea that the therapist must address these multiple modalities of an individual to identify and treat a mental disorder. According to MMT, each individual is affected in different ways and in different amounts by each dimension of personality, and should be treated accordingly for treatment to be successful. It sees individuals as products of interplay among genetic endowment, physical environment, and social learning history. To state that learning plays a central role in the development and resolution of our emotional problems is to communicate little. For events to connect, they must occur simultaneously or in close succession. An association may exist when responses one stimulus provokes, are predictable and reliable, similar to those another provokes. In this regard, classical conditioning and operant conditioning are two central concepts in MMT.