Lindsay Lohan still has access to Adderall in rehab.

The 'Mean Girls' actress - who is at the start of her 90-day court-ordered treatment at the Betty Ford Center in Rancho Mirage, California - will still be able to take the psychostimulant medication, which is used to treat attention deficit hyperactivity disorder (ADHD) and narcolepsy, according to TMZ.

Lindsay, 26, claims she has ADHD and requires the drug to alleviate symptoms, but doctors at the rehab facility are reportedly evaluating the actress alleged diagnosis and use of the medication and may decide to cut her off.

Meanwhile, the troubled star is expected to be under total lockdown for the remainder of her rehab stint and will not be allowed off the premises of the Betty Ford Center.

Leslie Place, a case manager at the facility, confirmed in a letter to Lindsay's lawyer: ''It is understood by the Betty Ford Center that your client is to remain on premises for the duration of her 90-day stay in treatment.''

Lindsay will be assigned a full team of carers - including a psychologist, dietician, chemical dependency technician and physician - who will devise a tailored care plan for the actress, and she will also be kept busy with a wide range of activities to fill her three month stay.

The letter explained: ''This team is responsible for assessing and working with each patient to an individualised plan of care and post-treatment recommendations designed to support ongoing recovery. These assessments take place within the first 72 hours of admission, depending on the medical and/or psychiatric state of the patient. An initial treatment plan is established upon admission and is developed as patient needs are identified and treatment progresses.

''Each day consists of a full schedule of treatment activities. These activities include, but are not limited to, individual therapy, speciality groups, fitness, educational lectures and group therapy.''