Sensory integration
Unusual responses to sensory stimuli are more common and prominent in children with autism, although there is not good evidence that sensory symptoms differentiate autism from other developmental disorders. Several therapies have been developed to treat Sensory processing disorder.  Some of these treatments (for example, sensorimotor handling) have a questionable rationale and have no empirical evidence. Other treatments have been studied, with small positive outcomes, but few conclusions can be drawn due to methodological problems with the studies. These treatments include prism lenses, physical exercise, auditory integration training, and sensory stimulation or inhibition techniques such as "deep pressure"—firm touch pressure applied either manually or via an apparatus such as a hug machine or a pressure garment. Weighted vests, a popular deep-pressure therapy, have only a limited amount of scientific research available, which on balance indicates that the therapy is ineffective. Although replicable treatments have been described and valid outcome measures are known, gaps exist in knowledge related to Sensory processing disorder and therapy. Because empirical support is limited, systematic evaluation is needed if these interventions are used.

The term Multisensory integration in simple terms means the ability to use all of ones senses to accomplish a task. Occupational Therapists sometimes prescribe sensory treatments for children with Autism however in general there has been little or no scientific evidence of effectiveness.

A 2008 book My Stroke of Insight by Jill Bolte Taylor gives some insight, from a brain researcher's point of view, on what sensory processing disorder feels like. Other books on sensory integration include The Out of Sync Child - Recognizing and Coping with Sensory Processing Disorder by Carol Kranowitz and Lucy Jane Miller.

Animal-assisted therapy
Animal-assisted therapy, where an animal such as a dog or a horse becomes a basic part of a person's treatment, is a controversial treatment for some symptoms. A 2007 meta-analysis found that animal-assisted therapy is associated with a moderate improvement in autism spectrum symptoms. Reviews of published dolphin-assisted therapy (DAT) studies have found important methodological flaws and have concluded that there is no compelling scientific evidence that DAT is a legitimate therapy or that it affords any more than fleeting improvements in mood.

Neurofeedback attempts to train individuals to regulate their brainwave patterns by letting them observe their brain activity more directly. In its most traditional form, the output of EEG electrodes is fed into a computer that controls a game-like audiovisual display. Neurofeedback has been evaluated with positive results for ASD, but studies have lacked random assignment to controls.

Patterning is a set of exercises that attempts to improve the organization of a child's neurologic impairments. It has been used for decades to treat children with several unrelated neurologic disorders, including autism. The method, taught at the The Institutes for the Achievement of Human Potential, is based on oversimplified theories and is not supported by carefully designed research studies.

In packing, children are wrapped tightly for up to an hour in wet sheets that have been refrigerated, with only their heads left free. The treatment is repeated several times a week, and can continue for years. It is intended as treatment for autistic children who harm themselves; most of these children cannot speak. Similar envelopment techniques have been used for centuries, such as to calm violent patients in Germany in the 19th century; its modern use in France began in the 1960s, based on psychoanalytic theories such as the theory of the refrigerator mother. Packing is currently used in hundreds of French clinics. There is no scientific evidence for the effectiveness of packing, and some concern about risk of adverse health effects.

Transcranial magnetic stimulation
Transcranial magnetic stimulation, which is a somewhat well established treatment for depression, has been proposed, and used, as a treatment for autism. A review published in 2013, however, found insufficient evidence to support its widespread use for autism spectrum disorders.

Environmental enrichment
Environmental enrichment is concerned with how the brain is affected by the stimulation of its information processing provided by its surroundings (including the opportunity to interact socially). Brains in richer, more-stimulating environments, have increased numbers of synapses, and the dendrite arbors upon which they reside are more complex. This effect happens particularly during neurodevelopment, but also to a lesser degree in adulthood. With extra synapses there is also increased synapse activity and so increased size and number of glial energy-support cells. Capillary vasculation also is greater to provide the neurons and glial cells with extra energy. The neuropil (neurons, glial cells, capillaries, combined together) expands making the cortex thicker. There may also exist (at least in rodents) more neurons.

Research on nonhuman animals finds that more-stimulating environments could aid the treatment and recovery of a diverse variety of brain-related dysfunctions, including Alzheimer's disease and those connected to aging, whereas a lack of stimulation might impair cognitive development.

Research on humans suggests that lack of stimulation (deprivation—such as in old-style orphanages) delays and impairs cognitive development. Research also finds that higher levels of education (which is both cognitively stimulating in itself, and associates with people engaging in more challenging cognitive activities) results in greater resilience (cognitive reserve) to the effects of aging and dementia.

Massage therapy
A review of massage therapy as a symptomatic treatment of autism found limited evidence of benefit. There were few high quality studies, and due to the risk of bias found in the studies analyzed, no firm conclusions about the efficacy of massage therapy could be drawn.