Cognitive Impairment Associated with Schizophrenia: A Case Report

Introduction: First-generation antipsychotics could reduce the positive symptoms of schizophrenia but also impair cognitive function. Cognitive and negative symptoms in schizophrenia could be a significant burden experienced both by the patients and caregivers. Thus the treatment of cognitive impairment associated with schizophrenia should be addressed properly. The purpose of writing this article is to increase awareness in administering antipsychotics to elderly patients with schizophrenia, especially in the cognitive aspect and how to overcome possible cognitive decline. Case: An outpatient female schizophrenic patient who was on first-generation antipsychotic treatment complained of forgetfulness. The complaint started 5 years after she received her treatment. While she could still perform her activities of daily living independently, her instrumental activities of daily living were impaired. Her food got burnt while she was cooking, and she also took her medicine excessively because she forgot about it. Both of those events could be very dangerous for her. Discussion: Antipsychotics are the first-line pharmacotherapy for the treatment of schizophrenia but could also cause cognitive impairment. Management of cognitive impairment associated with schizophrenia could be performed both non-pharmacologically, by giving cognitive remediation therapy or physical exercise, and pharmacologically, by giving cholinergic agents such as donepezil. Conclusions: Cognitive impairment associated with schizophrenia should be managed as well as psychotic symptoms.

INTRODUCTION

Schizophrenia is a severe mental illness with a 1% lifetime prevalence[1],[2]. It is considered a leading cause of disability worldwide, so it needs to be treated properly[3]. Cognitive and negative symptoms in schizophrenia could be a significant burden experienced both by the patients and caregivers because they are closely associated with the patient’s functioning[4]. While giving antipsychotics as the main pharmacotherapy for schizophrenia, interventions for cognitive and negative symptoms are also needed to be adequately taken[5]. Cognitive decline in patients with schizophrenia could be caused by several factors, such as low cognitive/brain reserve due to schizophrenia itself, accelerated cognitive aging, increased cerebrovascular disease, or side effects of subsequent treatment with antipsychotics or other medications[6].

CASE

The patient was a 64-year-old Javanese female. She was married and had 3 children but currently lived alone with her husband. She came to the clinic for routine control. She suffered with schizophrenia and had been on regular medication for the past 12 years. Her first symptoms at that time were difficulty sleeping, feeling scared of a lot of people with no reason, and experiencing visual hallucination. She received antipsychotic with some dosage adjustments during her treatment and had been consuming Trifluoperazine 2.5 mg twice a day as her maintenance therapy until now. Currently she complained that she was being forgetful, especially if she got distracted while doing something. For example, she forgot that she had taken her medicine, so she took her medicine again, and sometimes she forgot that she had eaten and asked to eat again.

According to her husband, complaints of forgetfulness appeared more or less 5 years after the patient underwent treatment for schizophrenia. Complaints of forgetting appeared occasionally at first but increased frequently over time. The first sign that made him notice her forgetfulness was that she forgot that she was cooking and the food got burnt. She also took excess medication several times because she forgot that she had previously taken it and insisted on taking her medicine again. On a daily basis, she did not do much activity and spent more time watching television. Her Lawton Instrumental Activities of Daily Living scale score was 2 (dependent). She could still carry out her daily activities independently and properly. Her Katz Index of Independence in Activities of Daily Living score was 6 (independent). She could also perform her prayer movements correctly and in order. Prior to her illness, she was diligent, tidy, conscientious, and paid attention to details. After being sick, she became lazy and lacked the initiative to do things, only doing what her husband asked her to do.

The patient did not have a history of hypertension, diabetes, or other chronic disease that required routine medication or hospitalization. She was never hospitalized either due to physical or mental illness. Neither the patient nor the family had a history of prior psychiatric disorder. Her physical examination was within normal limits. Her Mini-Mental State Examination (MMSE) score at the time of examination was 14, which indicated severe cognitive impairment. There was Alzheimer's disease as her differential diagnosis at first, but considering that the onset of symptoms was 5 years after her antipsychotic consumption, at the age of 57 years old, with no disorientation in familiar places, no difficulty with language or finding words, no family history of dementia, and her lack of initiatives, we thought her cognitive decline is more likely caused by the side effects of antipsychotics rather than Alzheimer's disease.

DISCUSSION

Schizophrenia is a chronic neuropsychiatric disorder characterized by positive symptoms (such as hallucinations and delusions), negative symptoms (such as lack of motivation, social withdrawal, apathy, and amotivation), and cognitive impairments (including memory, attention, and executive functioning)[3],[7],[8]. 80% of schizophrenia patients show clinically significant cognitive impairment, and that is why it is called “dementia praecox” or premature dementia by Kraepelin many years ago[9]. While many patients suffering with schizophrenia experience cognitive impairment, the Diagnostic and Statistical Manual of Mental Disorders (DSM) has not included cognitive impairment as part of diagnostic criteria for schizophrenia[10]. After the onset of schizophrenia, usually it would lead to permanent socio-occupational decline, even if the psychotic signs remit[11].

Antipsychotics are the first-line pharmacotherapy for the treatment of schizophrenia[12]. The patient we discuss received Trifluoperazine as her antipsychotic for 12 years with some dose adjustments during the treatment over the years. Trifluoperazine belongs to typical or first-generation antipsychotics (FGAs) and is well known for treating positive symptoms of schizophrenia (such as hearing voices, seeing things, and having strange beliefs) by blocking postsynaptic D2 receptors in mesolimbic and mesocortical projection[12],[13]. It is inexpensive and widely accessible, although some studies say FGAs have the possibility to impair procedural learning and memory and may cause cognitive impairment worse in schizophrenia patients, especially at high doses[3],[13],[14]. A network meta-analysis on studies of antipsychotic effects found that haloperidol, which belongs to FGA, had negative effects on cognition[15]. One of the explanations for cognitive dysfunction under antipsychotic medication is the dopamine receptor blockade. Unbalanced dopamine receptor blockade leads to significantly less striatal and telencephalic activity when cognitive tasks are performed, with the most significant effects being on motor speed and attention[14]. The dose of antipsychotic medication also plays a role

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