Dialectical behavior therapy (DBT) treatment is a cognitive-behavioral approach that emphasizes the psychosocial aspects of treatment.
Full-spectrum light is light that covers the electromagnetic spectrum from infrared to near-ultraviolet, or all wavelengths that are useful to plant or animal life; in particular, sunlight is considered full spectrum, even though the solar spectral distribution reaching Earth changes with time of day, latitude, and atmospheric conditions.
Lamps that produce only infrared for heating purposes do not exist to my knowledge. The reason is that the mechanism used by heat lamps to produce heat does not permit much control of the wavelengths of light emitted. The spectrum is determined by the temperature of the filament via blackbody radiation. There are LEDs and lasers that produce only infrared light, but these are not used for heating.