These difficulties are less frequently identified and thus undertreated when compared with the neurological symptoms. Most problems are associated with more severe intellectual delay or associated with childhood and adolescence, and some (for example depressed mood) may be unreported if the person is unable to communicate. TAND can be investigated and considered at six levels: behavioural, psychiatric, intellectual, academic, neuropsychological, and psychosocial.Behavioural problems most commonly seen include overactivity, impulsivity and sleeping difficulties. Also common are anxiety, mood swings, and severe aggression. Less common are depressed mood, self-injury, and compulsive behaviours.People with TSC are frequently also diagnosed with psychiatric disorders: autism spectrum disorder (ASD), attention deficit hyperactivity disorder (ADHD), anxiety disorder and depressive disorder. TSC is one of the most common genetic causes of autism spectrum disorder, which affects nearly half of people with TSC. ASD is more common in TSC2 than TSC1 and more common with earlier and more severe epilepsy, and with lower intellectual ability. ADHD is nearly as frequently seen in TSC as ASD (up to half of all people with TSC). Anxiety and depressive disorders, when they occur, are typically diagnosed in early adulthood and among those intellectually able to express their moods. Schizophrenia (and symptoms like hallucinations or psychosis) is no more common in TSC than the general population.The intellectual ability of people with TSC varies enormously. About 40–50% have a normal IQ. A normal IQ is much more commonly seen in TSC1 than TSC2, and profound intellectual disability seen in 34% of TSC2 compared with 10% of TSC1 in one study.
Neurological
Three types of brain tumours are associated with TSC:

Giant cell astrocytoma: (grows and blocks the cerebrospinal fluid  flow, leading to dilatation of ventricles causing headache and vomiting)
Cortical tubers: after which the disease is named
Subependymal nodules: form in the walls of ventriclesClassic intracranial manifestations of TSC include subependymal nodules and cortical/subcortical tubers.The tubers are typically triangular in configuration, with the apex pointed towards the ventricles, and are thought to represent foci of abnormal neuronal migration. The T2 signal abnormalities may subside in adulthood, but will still be visible on histopathological analysis. On magnetic resonance imaging (MRI), TSC patients can exhibit other signs consistent with abnormal neuron migration such as radial white matter tracts hyperintense on T2WI and heterotopic grey matter.Subependymal nodules are composed of abnormal, swollen glial cells and bizarre multinucleated cells which are indeterminate for glial or neuronal origin. Interposed neural tissue is not present. These nodules have a tendency to calcify as the patient ages. A nodule that markedly enhances and enlarges over time should be considered suspicious for transformation into a subependymal giant cell astrocytoma, which typically develops in the region of the foramen of Monro, in which case it is at risk of developing an obstructive hydrocephalus.A variable degree of ventricular enlargement is seen, either obstructive (e.g. by a subependymal nodule in the region of the foramen of Monro) or idiopathic in nature. Neuropsychiatric
About 90% of people with TSC develop a range of neurodevelopmental, behavioural, psychiatric, and psychosocial difficulties. The "TSC‐associated neuropsychiatric disorders" are abbreviated TAND.